I. AUTHORS COMMENTS
respiratory disease has emerged as a major nationwide health
problem. Chronic obstructive pulmonary diseases have increased
to epidemic proportions and are currently significant causes
of morbidity and mortality in this country. These conditions
have revolutionized the practice of pulmonary medicine and
have promoted the emergence of the allied health specialties,
such as respiratory therapy and pulmonary nursing.
has also developed increasing recognition of the dangers of
occupational lung diseases and much has been done to prevent
them and promote early diagnosis. Despite these new developments,
tuberculosis remains a significant worldwide health problem.
Many advances, however, have made treatment much easier (more
available drugs and shorter treatment programs).
disease is not restricted to any age group. Each year tens
of thousands of children under the age of five die from various
pulmonary causes and even more adult deaths occur annually
due to chronic lung disease.
is true in many other organ diseases, prevention and early
diagnosis are the keys to ultimate control and cure. Respiratory
therapists can play a very important role in assisting physicians
in gathering clues in the clinical history, examination and
physiologic measurements that may lead to early detection
and treatment. To accomplish this end, respiratory therapists
must learn about lung disease. Learning involves not only
reading and studying didactic information, but devoting time
to clinical rounds with a teacher well versed in the spectrum
of lung disease.
II. LEARNING OBJECTIVES
completion of this module, the student will:
Differentiate between the various chronic obstructive pulmonary
Differentiate between the various restrictive pulmonary
the pathophysiology of the infectious respiratory disease
the pathophysiology of pulmonary embolic disease.
the effects of pulmonary pathology due to trauma.
III. ASSIGNED READING
there are no clinical procedures to perform for this module,
the student is expected to spend more time on assigned readings.
Because of the wide array of disease states the therapist
encounters, familiarity obtained by these readings will aid
in proper diagnosis and treatment.
For your own benefit, we highly recommend reviewing the supplemental
reading, however it is not required.
and Hodgkin, Respiratory Care - A Guide to Clinical Practice.
Philadelphia: J.B. Lippincott Company.
Obstructive Pulmonary Disease:
Small Airways Disease
Thoracoskeletal Disease of the Chest Wall
Infectious Pulmonary Disease:
Pulmonary Fungal Infection
Pathology Due to Trauma:
Penetrating Chest Wounds
Flail Chest/Rib Fractures
V. INSTRUCTIONAL CONTENT
cover the entire topic of pulmonary diseases in a single module
is a difficult if not impossible task. In order to provide
the respiratory therapy student with a sound general concept
of the pathophysiology of the majority of pulmonary disease,
this module has been broken down into several major categories:
Chronic obstructive pulmonary disease
2. Restrictive pulmonary disease
3. Infectious pulmonary disease
4. Pulmonary embolic disease
5. Pulmonary pathology due to trauma
beginning the discussion of the individual diseases, it is
important for the student to be able to differentiate between
obstructive and restrictive disease and acute and chronic
disease states. Obstructive pulmonary disease is generally
defined as a state in which there is an obstruction to expiratory
air flow. This disorder can be determined by simple spirometry.
On the other hand, restrictive pulmonary disease is defined
as disease processes in which there is a restriction to inspiratory
air flow. Both obstructive and restrictive diseases can occur
acutely and chronically.
pulmonary disease is defined as one in which the onset of
symptoms is rapid and severe. An acute disease usually will
follow a shorter course than chronic disease states. Chronic
disease is defined as any disease with a long, drawn-out course.
Acute and chronic are antonyms.
adult pulmonary disease will be further discussed according
to certain major characteristics. The following terms will
be used in the discussion:
Etiology: The cause of the disease.
The frequency of occurrence of the disease in relation to
The origin and development of the disease.
Pathology: The conditions produced by the disease.
Manifestations: Those manifestations which can be clinically
observed by actual patient observation.
Radiographic Examination: Data obtained by x-ray.
Sputum Examination: Data obtained from sputum collection.
Laboratory Findings: Data obtained from laboratory
Pulmonary Function Studies: Data obtained from PFTs.
Diagnosis: Establishing the name of the disease by
evaluation of the above data.
Management: How the disease is treated.
Disease Course: The progression of the disease.
Prognosis: Prediction of the final outcome of the
attempt will be made to cover each of these aspects of the
individual pulmonary diseases. A great deal of additional
information may be obtained from the resource readings and
it will be most important for the student to study these sources
to obtain in-depth knowledge of pulmonary pathology.
2. Chronic Obstructive Pulmonary Disease:
obstructive pulmonary disease (COPD) is a title given to a
number of disease entities that are all similar and often
difficult to distinguish from one another. This is due in
part to the fact that they often overlap; the patient may
well have more than one of the disease entities.
COPD includes chronic bronchitis, pulmonary emphysema and
asthma. Closely associated with these diseases are bronchiectasis,
cystic fibrosis, bronchiolitis and small airway disease. Bronchiolitis
and cystic fibrosis are predominantly pediatric disorders
and should be covered at length in a pediatric module.
chronic obstructive pulmonary diseases have much in common.
They tend to be chronic illnesses and exhibit an obstructive
component in pulmonary function studies. Because of these
similarities, treatment is often much the same for each of
the COPD states.
bronchitis is best defined as a chronic productive cough for
at least three months of the year for two successive years.
The patient with asthmatic bronchitis suffers
from chronic bronchitis accompanied by frequent bouts of bronchospasm.
bronchitis is found in 10 to 20% of the adult population.
It is more common in men than women (a 10:1 ratio).
key factor in the etiology of chronic bronchitis is cigarette
smoking. There is also an increased incidence of the disease
in areas associated with air pollution. Infection can cause
exacerbation of the bronchitis into an acute state. Anything
causing prolonged irritation of the bronchial mucosa can cause
primary pathological feature of chronic bronchitis is inflammation
of the airways. This inflammation leads to hypertrophy of
the bronchial mucosal glands and an increase in the number
of goblet cells. Increased amounts of mucus are produced.
The bronchial mucosa becomes edematous.
increased mucus production, mucus gland hypertrophy and edematous
tissues cause increased airway resistance. This is the cause
of the obstructive component of chronic bronchitis.
above changes are accompanied by mucociliary impairment and
some actual loss of cilia. Phagocytic activity is decreased
by the increase in mucus production and decreased mucus infection.
chronic bronchitis is accompanied by vascular changes due
to the hypoxia that it causes. Pulmonary hypertension and
an increase in pulmonary vascular resistance may occur and
lead to right ventricular hypertrophy or cor pulmonale.
major symptom of chronic bronchitis is the cough accompanied
by excessive expectoration. The cough is usually loose and
rattling, worsening in the morning and at night.
Sputum is mucoid and difficult to expectorate. It varies in
color from white to yellow or gray.
difficulties often appear at about thirty years after the
onset of lung injury. Shortness of breath is not marked, however,
unless CHF is involved. The chronic bronchitis patient often
suffers frequent attacks of acute bronchitis in periods of
damp or cold weather.
physical examination reveals either a normal or barrel
chest. Rhonchi and wheezes may be heard throughout the lung
fields and expiration time is often prolonged. In extreme
cases, cyanosis may present, along with clubbing of the digits.
In the later stages, pulmonary hypertension may cause neck
vein distention and peripheral edema.
function tests indicate obstructive airway disease. The flow
rate measurements (including FEV1, FEV1/FVC and FEF25-75)
are decreased. The degree of abnormality determines whether
the disease state is mild, moderate or severe.
blood gases may exhibit a carbon dioxide retention accompanied
by hypoxemia. A second polycythemia may also be present due
to the chronic hypoxemia.
chest x-ray is normal in 20 to 40% of the cases of chronic
bronchitis. This usually will occur if mainly the larger airways
are affected. If the more peripheral bronchi are involved,
hyperinflation and a flattened diaphragm may be observed.
Increased bronchovascular markings may be present and, on
bronchography, dilated bronchial glands may be seen.
first step in the treatment of chronic bronchitis is to have
the patient stop smoking. Air pollution and occupational hazards
should also be avoided.
patient should be taught to maintain good bronchial hygiene.
Effective cough methods should be taught, along with postural
drainage. A high fluid intake should be encouraged to promote
hydration of secretions. If the patient develops an upper
respiratory infection, early antibiotic therapy should be
therapy and expectorants may be helpful. In the patient with
asthmatic bronchitis, steroid therapy is often
is a pathological process characterized by an abnormal increase
of the respiratory portion of the lung beyond the terminal
bronchioles with attenuation and loss of pulmonary septal
tissues. It is characterized by dilation and destruction of
all or part of the acinus, the tissue distal to the terminal
are may different types of emphysema. The following types
will be discussed:
2. Panlobular emphysema
3. Focal dust emphysema
4. Paraseptal emphysema
5. Alveolar-duct emphysema
6. Paracitatrical (scar) emphysema
7. Unilateral (Swyer-James syndrome, hyperlucent lung
syndrome and MacLeods syndrome) emphysema
addition, Alpha-1 antitrypsin deficiency will be discussed.
is considered to be an obstructive disorder not because the
airways are narrowed, but because there is premature airway
closure on expiration due to disruption of the alveolar septum
and a subsequent loss of lung elasticity.
emphysema primarily affects the middle of the acinus and
the respiratory bronchioles. The centrilobular type of emphysema
is often found in patients with chronic bronchitis. It is
common for patients with this variety of emphysema to retain
secretions and develop respiratory infections. This type of
emphysema occurs primarily in the upper two-thirds of the
lung fields and is seldom seen in nonsmoking patients.
(panacinar) emphysema involves the entire acinus. The
alveoli tend to enlarge and appear very similar to the alveolar
duct. This type of emphysema is found mainly in the lower
lobes. Panlobular emphysema often occurs in the elderly and,
like centrilobular emphysema, is more often found in males
than in females. However, females with emphysema are more
likely to have panlobular emphysema than centrilobular emphysema.
dust emphysema is characterized by inhaled coal dust in
the respiratory and terminal bronchioles accompanied by dilation
of the bronchioles. There is little, if any, impairment of
(lineal) emphysema is usually a localized, asymptomatic
form of emphysema and is thought to be a major cause of spontaneous
pneumonthorax. The lung periphery and the pleura are primarily
involved. Bullae may develop from disrupted alveoli and it
is thought that this type of emphysema may be an element of
emphysema is commonly found in elderly patients and is
characterized by an increase in the diameter of the alveolar
ducts. The patient with alveolar-duct emphysema is rarely
symptomatic. The cause of the disease is most likely due to
airway dilation as a direct result of the aging process.
(scar) emphysema occurs in areas of pulmonary scarring
and is characterized by small areas of alveolar destruction
emphysema is also known as MacLeods syndrome, hyperlucent
lung and Swyer-James syndrome. This disease is characterized
by one lung being more radiolucent than the other. The affected
lung is often afflicted with bronchitis, bronchiolitis and
air trapping. Patients with this disease, however, are often
asymptomatic. The hyperlucency is most likely due to decreased
vascular markings and widespread emphysema in that lung. The
etiology in the majority of cases is most likely infection.
(a-1) antitripysin deficiency is a genetic abnormality
resulting in emphysematous lung tissue. Alpha-1 antitrypsin
is the major proteinase inhibitor in normal adult plasma.
When a deficiency of this substance is present, the lung parenchyma
is destroyed by leukocyte proteases. Panlobular emphysema
is usually seen and affects mainly the lower lobes.
with severe deficiency are usually homozygous (possess like
pairs of genes with the genetic abnormality) and often develop
the disease at age thirty five or older. Those with a milder
deficiency are usually heterozygous and become symptomatic
at approximately fifty years or older.
antitrypsin deficiency is responsible for less than 5% of
the reported cases of emphysema. One-third of the patients
thirty five years old or less exhibit an alpha-1 antitrypsin
deficiency. Genetic counseling should be given to patients
with this disorder to prevent reoccurrence.
etiology of emphysema is questionable, but cigarette smoking
and environmental pollutants are definitely key causative
factors. Infection, retained secretions in the small airways
and subsequent air trapping can all cause destruction and
distention of the alveolar tissue. As mentioned earlier in
the various types of emphysema, old age, repeated respiratory
infections, heredity and congenital anomalies can also be
begins with small holes or fenestrations in the alveolar membranes.
Eventually as these fenestrations increase in number, they
become larger; breaking, tearing and rupturing the alveolar
membrane. Septal destruction also appears due to frequent
coughing, hyperinflation and air trapping.
this alveolar destruction occurs long before the patient becomes
symptomatic. As the alveoli undergo these changes, there is
a subsequent loss of surface area available for diffusion
of gases. When this occurs, arterial blood gas values become
abnormal and hypoxemia and carbon dioxide retention may present.
Diffusing capacities decrease and compliance increases as
elasticity decreases. The lung tends to over-expand and become
larger as the loss of elasticity continues. A barrel
shaped appearance of the chest results. The ribs have a tendency
to separate and the diaphragm flattens to allow for the increased
of breath on exertion is the earliest clinical sign of emphysema.
Work of breathing is greatly increased as more and more effort
is required to exhale, due to airway collapse and air trapping.
Cough and expectoration may be present, but are generally
not severe in the early stages of emphysema. Eventually, the
patient will experience generalized symptoms of orthopnea,
weight loss, loss of appetite, inactivity and depression.
On physical examination, a prolonged expiratory phase is encountered.
End-expiratory wheezing may be present and breath sounds may
be decreased to absent. There is hyper-resonance to percussion
and a decrease in tactile fremitus. Chest expansion decreases,
A-P diameter increases, work of breathing increases and there
is often a barrel chest appearance.
chest x-ray shows a flattened diaphragm, overall hyperinflation,
a vertical heart and a possible decrease in pulmonary vascular
markings. There is an overall hyperlucency of the lung fields.
The chest x-ray is not a good tool in the diagnosis of emphysema,
as these symptoms are also seen in other pulmonary diseases.
function studies, of course, show obstructive pulmonary disease.
If an element of bronchitis is present, airway resistance
will increase; DLCO decreases, TLC increases (as does FRC
and RV) and VC may be normal or decreased. If pulmonary emphysema
is the only disease present, there will generally be a poor
response to bronchodilator therapy due to the nonreversible
components of airway collapse. Helium and nitrogen washout
tests show poor distribution of ventilation.
blood gases usually indicate hypoxemia and possible carbon
dioxide retention. The degree of severity of these abnormalities
is dependent upon the extensiveness of the emphysema, the
presence of other diseases and the occurrence of exacerbations.
is an irreversible disease state, but with treatment the parenchymal
damage may be prevented from going any further. Treatment
includes avoidance of smoking and airway irritants. Good bronchial
hygiene, nutrition and adequate fluid intake are encouraged.
If there is a significant response to bronchodilator therapy,
it should be instituted. A good pulmonary rehabilitation program
is indicated in the patient with emphysema. If necessary,
supplemental oxygen and respiratory therapy may be used in
the patients home.
is a disease characterized by permanent irreversible dilation
of either the bronchi, bronchioles or both. It is diagnosed
with bronchography. A cardinal symptom is expectoration of
antibiotic therapy has been introduced, bronchiectasis occurs
much less frequently than in the past.
can be caused by a number of pulmonary insults. As a rule,
bronchiectasis occurs following a primary insult accompanied
by pulmonary infection. The following processes have been
implemented as predecessors to bronchiectasis: necrotizing
pulmonary infections, repeated pneumonias, cystic fibrosis,
immunologic deficiency status, pulmonary neoplasm, tuberculosis,
Kartagners disease (bronchiectasis and sinus inversus),
foreign body aspiration and Agammoglo bulinema.
are three types of bronchiectasis:
1. Cylindrical bronchiectasis
2. Saccular bronchiectasis
3. Mixed Bronchiectasis
the cylindrical or tubular type of bronchiectasis,
fusiform (tapered at the end) dilations occur within the airway.
The dilated airways then fill with purulent secretions. This
type of bronchiectasis often occurs as a result of severe
bronchiectasis is characterized by irregular grape-like
dilations and narrowing in the airways. Again, these airways
fill with pooled purulent secretions.
third type of bronchiectasis is a mixture of the other two
types and is rightfully termed mixed bronchiectasis.
exact mechanisms causing bronchiectasis are unknown. It is
thought that repeated attacks to the airway by various disease
states cause damage to the epithelial tissue, inflammation,
narrowing of the airway alternating with dilation of the airway
and finally erosion of the bronchial wall.
patient with bronchiectasis presents with a productive cough
of large amounts of foul-smelling purulent sputum. Sputum
production peaks in early morning and immediately after the
patient rises. In 50% of the cases of bronchiectasis, hemoptysis
is present. A characteristic of sputum in severe cases of
bronciectasis is its quality of settling into three layers:
cloudy on top, saliva in the middle and purulent mucus on
may be present for a period of time with no symptoms noted.
Dyspnea will not normally be present in the bronchiectasis
patient. Often in more advanced cases, clubbing, malnutrition,
sinusitis, cor pulmonale, rales and hypoxemia may be present.
function studies are nonspecific in the diagnosis of bronchiectasis
and usually indicate obstructive airway disease. Significant
hypoxemia may be present due to a shunt effect.
chest x-ray results are generally negative, although increased
markings may be present within localized areas. The x-ray
may show some cystic spaces with recognizable air-fluid levels
and honeycomb appearance of fibrosis surrounding
bronchogram, however, is a more definite test for a diagnosis
of bronchiectasis. Bronchography is the process of instilling
a radio-opaque substance into the lung which will illustrate
the size and appearance of the tracheobronchial tree. In bronchiectasis,
the narrowing and dilation of the airways can be seen along
with pooling of secretions within these areas.
major component of a treatment regimen for bronchiectasis
is a good bronchial hygiene program and chest physiotherapy
to remove retained secretions. Appropriate antibiotic therapy
should be institued to treat pulmonary infections. A good
general rule in the treatment of bronchiectasis is to treat
it much the same as chronic bronchitis.
than twelve million Americans suffer from asthma, a chronic
obstructive pulmonary disease that makes the lungs extremely
sensitive. In response to allergens or exertion, the airway
mucosa becomes inflamed, the smooth muscles spasm, and the
secretory cells increase their production. The mechanism behind
asthma is a normal reflex of the sentries that protect the
human body against invasions by allergens or infection. Its
simply a defense that has become too powerful for the bodys
own good. For some reason, the immune cells that guard an
asthmatics bronchial tubes are in a perpetual state
of inflammation. And like jittery soldiers firing at a shadow,
the immune cells compound the problem by overreacting to triggers.
exposure to these perceived enemies, the cells fire so many
antibodies that airways to the lungs become jammed with mucus
and squeezed by bands of constricting muscle, triggering an
can produce severe shortness of breath, inability to perform
routine activities, and if improperly treated, can result
in respiratory failure and death. Each individual suffers
a different level of severity. Almost all patients with asthma
do enjoy a reversal of symptoms until something triggers the
next episode. Estimates of direct and indirect costs incurred
by asthmatics in 1990 totaled $6.2 billion. Asthma related
morbidity and mortality have increased in recent years in
the United States. The incidence of asthma is rising. Asthma
kills fourteen Americans of all ages every day. Asthma is
the number one chronic disease afflicting American children.
seven and twenty million Americans have asthma, and approximately
5% of all Emergency Room visits are due to asthma (National
Asthma Education Program Expert Panel, 1999). Asthma affects
4% to 5% of the population. There are at least two genetic
influences. One associated with the capacity to develop allergies
(atopy) and the second associated with the tendency to develop
hyper-responsiveness of the airways independent of atopy.
Genetic researchers have recently identified a region (locus)
on chromosome eleven that is associated with atopy. This locus
may contain an abnormal gene that encodes a part of the IgE
receptor. In asthma, the normal airway function designed to
protect the lungs (muscle contraction, mucosal swelling and
mucus formation), becomes excessive. For reasons not entirely
known, the airways become abnormally sensitive to infection,
weather, exercise, irritants and allergens. The muscles tighten
(bronchospasam) and the mucosa begins to swell, which reduces
the diameter of the airway. In addition, mucus production
is increased, sometimes forming sticky plugs in the bronchial
is a common chronic lung disease that affects individuals
of all ages. It is an inflammatory disease characterized by
hyper-responsiveness of the airways and episodic periods of
bronchospasm (spasm, or prolonged contractions, of the bronchial
smooth muscle). Asthma, is the Greek word for panting, imposing
a heavy burden of misery and danger. The disease is characterized
by the presence of reversible airway obstruction, airway inflammation,
and a variable degree of airway hyper-responsiveness. Allergens,
viral illnesses, exercise, cold, weather, certain medications,
and stress are all factors that exacerbate intermittent episodes
of bronchospasm. Biochemical, autonomic, immunologic, infectious,
endocrine, and psychologic factors are involved in varying
degrees. Most asthmatic episodes of bronchospasm are short-lived,
with freedom from symptoms between episodes; although airway
inflammation is present, even in asymptomatic individuals.
symptoms of asthma arise when the caliber of the
tiny air passages that conduct the air in and out of the lungs,
is reduced. These tubes, or bronchi and bronchioles, are narrowed
by the contraction of the thin layer of muscles that sheathes
each airway. In addition, the bronchial walls become inflamed
or swollen, from the secretion of thick, tenacious mucous
in the bronchial tubes. The inflammation resulting in hyperresponsiveness
of the airways is the major pathological feature of all types
of asthma. The release of inflammatory mediators produces
bronchial smooth muscle congestion, microvascular congestion,
increased tracheobronchial secretions, and muscosal edema.
is a unique combination of clinical and pathological findings.
It combines bronchial hyperresponsiveness with a distinctive
form of airway inflammation associated with increased mucous
production. The bronchial biopsy of even the mild asymptomatic
individual with asthma demonstrates epithelial disruption,
eosinophilic proliferation, actively degranulating mast cells,
and an increase in activated T-lymphocytes.
way the asthmatic inflammatory process manifests itself is
disease specific with the eosinophil playing a major role
and activated cytokines orchestrating the inflammatory component
of this illness. Asthma may be clinically indistinguishable
from bronchiolitis in infants and toddlers, becomes a more
easily definable illness from childhood to middle age and
then blends with a component of chronic obstructive lung disease
in older adults.
in asthma is an immediate or type I hypersensitivity reaction
that requires the presence of specific immunoglobulin E (IgE)
class of antibodies. This type of reaction occurs in individuals
who have atopy, which is a hypersensitivity state with a genetic
predisposition characterized by the production of an excessive
amount of IgE antibodies and against a variety of antigens.
About 10% to 20% of the general population are atopic and
have the tendency to develop hay fever, asthma, eczema, and
other IgE- mediated allergic reactions. These types of hypersensitivity
reactions result from the interaction of antigens (allergens)
with their specific IgE antibodies, which tend to attach to
the mast cells, basophilic ganulocytes, and perhaps other
cells. Mast cells have the highest concentration of IgE molecules
on their surface. The cross-linking of two IgE antibody molecules
by specific antigen signals the initiation of a series of
intracellular biochemical events resulting in the release
of several mediators. Some of these mediators are preformed
and stored at specially stainable granules, and many others,
before being released, are rapidly synthesized as a result
of the signal from the antigen-antibody interaction.
Among the many chemical mediators identified thus far, important
ones are: histamine, eosinophyil chemotactic factor of anaphylaxis
(EFC-A), neutrophil chemotactic factor (NCF), leukotrienes
(formerly known as slow-reacting substance of anaphyulaxis,
or SRS-A), prostaglandins, and platelet-activating factor.
In addition to mast cells, other cells, including macrophages,
neutrophils, eosinophils, and endothelial cells, are known
to produce many of these mediators as well as many cytokines.
Both T lymphocytes and B lymphocytes are also active participants
and interact with other cells in causing and maintaining airway
inflammation and other heightened reactivity. Plasma cells,
made from B-lymphocytes, are responsible from production of
pathophysiologic changes during an asthmatic episode are based
on the narrowing of the airways by contraction of smooth muscles,
mucosal and submucosal edema, and increased secretions. Increased
respiratory airway resistance results in decreased forced
expiratory flowrates and hyperinflation. Increased respiratory
work load is related to the increase in airway resistance.
In addition to mechanical dysfunction, abnormal distribution
of both ventilation and perfusion with their mismatching,
results in alteration of the arterial blood gases, particularly
hypoxemia. More severe and prolonged episodes may culminate
in hyercapnia from worsening of ventilation-perfusion mismatching
and ventilatory muscle fatigue.
the exact mechanism of airway hyperresponsiveness is unknown,
several factors, including genetic predispositon, autonomous
nervous imbalance and the alteration of adrenergic receptors
have been implicated in its development. Since everyones
asthma is different, asthma medications come in different
forms: liquids, pills, powders, vapors, and injections. Medications
are given in different ways to different people. Although
drug companies sell asthma medications under many brand names,
there are only a few major types: inhaled bronchodilatiors,
oral bronchodilators, corticosteroids, phosphodiesterace inhibitors,
cholinergic blockers, anti-leukotrienes, and prophylactic
bronchodilators to prevent the degranulization of the mast
TRIGGERS AND TREATMENTS
what triggers the asthmatic episode, and following a proper
medication plan, even on days when asthma isnt a problem,
are an asthmatics keys to maintaining a normal lifestyle.
Reliever medications act quickly to relieve bronchoconstriction
and its accompanying acute symptoms.
Controllers are medications taken daily on a long term
basis that are useful in getting and keeping persistent
asthma under control.
Ventolin, Maxiar, Alupent, Brethaire
Flovent Tilade, Beclovent, Vanceril Aerobid, Intal
Unidur, Theodur, Uniphyl
Phenylephrine: NEO- SYNEPHRINE
Racemic Epinephrine: ASTHMANEFRIN
Bitolterol mesylate: TORNALATE
Pirbuterol acetate: MAXAIR
Sameterol Xinafoate: SEREVENT
Cromolyn Sodium: INTAL
episodes can be brief and infrequent, or long and debilitating.
Most fatalities result from a condition termed status
asthmaticus in which the airways become completely plugged.
The diameter is reduced and the airway resistance is increased.
FOR SUFFERERS, KNOWLEDGE IS POWER
is now receiving the attention it deserves as a potentially
life-threatening but controllable disease.
is a major public health concern in the United States. As
indicated earlier in this monograph, Asthma morbidity and
mortality has risen substantially over the past 10 to 15 years,
as have costs associated with treatment. Considering the significant
clinical and financial implications surrounding this disease,
health providers need to recognize that patient education
is one of the most powerful tools for helping patients gain
more adequate control of their disease. A dedicated, collaborative
effort on the part of various members of the health care team
to educate patients, will ensure their compliance to self-management
and allow for attainment of therapeutic goals.
blood gases will show hypoxemia with severity dependent on
the severity of the attack. Hypercapnia may also be present
if the attack is severe. Sputum culture may
show eosinophilia in extrinsic asthma. If the asthma is extrinsic,
skin test will be positive for specific antigens.
function studies during an attack will show decreased VC,
FVC and flow rates; FRC, TLC and RV, however, will be increased
due to air trapping.
chest x-ray will show hyperinflation and an increased A-P
diameter. Areas of atelectasis may be present.
of the asthma attack deals mainly with bronchodilation. This
consists of a loading dose of aminophylline followed by an
intravenous drip, aqueous epinephrine (adrenaline) injection
and aerosolized bronchodialators (i.e., Albuterol).
addition, corticosteroid therapy may be instituted for several
days to reduce inflammation in the airways. If infection if
present, antibiotic therapy is instituted. Fluid intake should
be encouraged to promote secretion hydration.
blood should be analyzed and, if necessary, intubation and
assisted ventilation should be instituted.
treatment of asthma includes avoidance of contact with specific
allergens, inhaled irritants, extremes in humidity and temperature,
emotional upset and several medications (aspirin, inderol,
indocin and motrin).
medications may be used for long-term therapy including bronchodilators,
expectorants, antibiotic, corticosteroids, cromolyn sodium,
antihistamines and tranquilizers.
airways disease has also been referred to as early bronchitis
or bronchiolitis. It is said to be early as there
is a pulmonary abnormality present, but it cannot be detected
by routine pulmonary function studies.
etiology of small airways disease would be the same as for
bronchitis, including such factors as cigarette smoking, air
pollution, recurrent infection, or similar conditions capable
of causing prolonged irritation of the bronchial mucosa.
small airways less than 2 mm in diameter demonstrate early
closure and are inflamed. This early airway closure is increased
with inhaled irritants.
patient with small airway disease may not even be aware of
the problem. Minor symptoms, such as dyspnea on exertion,
may be present, along with rales, expiratory wheezing and
a prolonged expiration.
function studies show restrictive flow patterns. The chest
x-ray will likely be normal with the exception of those patients
with small areas of atelectasis.
major treatment of small airway disease is removal of the
causative agents, such as cigarettes or irritants in the air.
pulmonale is usually caused by chronic respiratory failure,
as seen in the COPD patient. It is defined in the function
and structure of the right ventricle of the heart resulting
from lung disease.
and hypercarbia cause constriction of the pulmonary arterioles
and an increased pulmonary vascular resistance. This causes
an elevation of the pulmonary artery pressure. A chronic elevation
causes a chronic stress to the right ventricle, which could
result in hypertrophy due to overwork. Right heart failure
artery pressure will be high. Hypoxemia, tachypnea, orthopnea,
dyspnea, thoracic pain, cyanosis, neck vein distention, a
fourth heart sound and a right ventricular gallop (S-3) are
found on clinical examination. The patient will exhibit the
clinical signs of severe dyspnea. Wheezing, prolonged expiration
and rales will be heard with auscultation.
EKG is the most valuable diagnostic tool in cor pulmonale.
The EKG may indicate right ventricular enlargement. Right
heart catheterization will show increased pulmonary arterial
pressures and a normal pulmonary capillary wedge pressure.
Again, arterial blood gases will show severe hypoxemia and
chest x-ray may be useful in indicating increased pulmonary
vascular markings. If the cor pulmonale is long standing,
right ventricular enlargement may be viewed.
of cor pulmonale involves decreasing the workload of the right
ventricle by decreasing pulmonary artery pressures. If the
increased workload is due to hypoxemia and acidosis, these
abnormalities should be treated. In other words, if the underlying
cause is found and treated, the symptoms should resolve.
fibrosis or mucoviscidosis is a hereditary disease characterized
by dysfunction of exocrine glands and manifested by chronic
pulmonary disease, pancreatic insufficiency, abnormally high
electrolyte concentration in sweat, and sometimes abnormalities
of other organs. Although characteristically a disease of
early childhood, cystic fibrosis is seen more and more in
adolescents and young adults because of improvement in early
diagnosis and management. With early recognition and institution
of proper treatment, pancreatic insufficiency rarely constitutes
a serious problem nowadays; whereas, the pulmonary complications
of cystic fibrosis escape pulmonary involvement and most patients
Etiology and incidence
fibrosis is a hereditary disease transmitted as a Mendelian
recessive trait. The single-gene carriers (heterozygotes)
have no clinically demonstrable disease. If both parents are
carriers, their children, regardless of their sex, would have
a 25% chance of having cystic fibrosis and a 50% chance of
being carriers. Thus both parents of a child with cystic fibrosis
fibrosis is more common in whites than blacks. Its incidence
in whites has been estimated to be 1 in 2000 live births.
It is the most frequent lethal hereditary disease in the United
States. The basic defect in cystic fibrosis has remained unknown,
but it has been postulated to be due to an inborn error in
Pathogenesis and pathology
two separate and distinct pathophysiologic features of cystic
fibrosis are high concentration of sweat electrolytes and
abnormality of mucus secretion and elimination. Sweat electrolyte
abnormality is present at birth and continuously throughout
the patients life. It has no relationship to severity
of disease or extent of involvement of other organs. Chloride
and sodium content of sweat are particularly increased, sometimes
being several times normal. As a diagnostic tool, the determination
of sweat electrolytes has been most valuable. Clinical consequence
of this abnormality has not been of significance, except for
excessive and sometimes dangerous salt loss with prolonged
exposure to heat.
abnormality of mucus, its secretion and elimination, and the
resultant obstructive changes constitute the basic mechanism
of the pathologic process in cystic fibrosis. Because of the
presence of large numbers of mucus-secreting elements in the
pancreas and tracheobronchial tree, these organs are particularly
susceptible and are almost always involved in cystic fibrosis.
fibrosis originally referred to the pathologic changes in
the pancreas, where dilated glands and ducts, fibrosis, and
degeneration of parenchyma are characteristic features. Pancreatic
insufficiency, causing inadequate digestion and absorption
of food, may result in severe malnutrition in these patients,
mostly when they are not properly treated.
lungs are involved to varying degrees in virtually all patients
with cystic fibrosis. Secretion of viscous and tenacious mucus
throughout the tracheobronchial tree causes airway obstruction,
which is the basis for the wide variety of pathologic changes
seen in the lungs of patients dying from cystic fibrosis.
Atelectasis, pneumonia, bronchiectasis, peri-bronchitis, emphysema,
abscess, and fibrosis are seen in various combinations. Obstruction
and retained secretions lay the ground for bacterial infection,
which plays a major role in development of most of these pulmonary
complications. Staphylococcus aureus and Pseudomonas aeruginosa
are frequently cultured from the sputum of these patients.
insufficiency is the cause of most gastrointestinal manifestations
of cystic fibrosis, which include abdominal distention, despite
ravenous appetite. Sometimes obstructive complications of
the gastrointestinal tract may occur. Meconium ileus is due
to plugging of the distal end of the small intestine by putty-like
meconium. The intestinal obstruction in this condition is
present at birth. There are other less common extrapulmonary
manifestations whose discussion is beyond the scope of this
lesson. Pulmonary complications, which are by far the most
important and potentially fatal manifestations of cystic fibrosis,
eventually develop in all patients. The time of onset of clinical
pulmonary manifestation is quite variable; they may be apparent
within a few weeks of birth or may occur years later. Cough
is the earliest and most common symptom. It is initially nonproductive,
but may shortly be productive of thick and tenacious sputum.
Repeated bouts of respiratory-tract infection cause frequent
exacerbation of these symptoms. With progressive and irreversible
damage to the lungs, dyspnea is soon added to the clinical
picture. Dyspnea may become quite severe with advancing disease.
Hemoptysis, which may be massive, is not uncommon in these
physical examination, in addition to signs of malnutrition
and poor body development, signs of pulmonary involvement
are frequently present. The chest may be barrel-shaped and
hyper-resonant to percussion. Changes in breath sounds with
varying adventitious sounds are often detected. The patient
may be in respiratory distress, using the accessory respiratory
muscles. Cyanosis and other signs of respiratory failure,
including cor pulmonale, may be apparent in more advanced
stages of the disease. Clubbing of fingers and toes is a common
examination of the chest in patients with pulmonary involvement
usually shows evidence of diffuse hyperinflation, increased
lung markings, and irregular densities. Mucoid impaction and
areas of atelectasis may be demonstrated. Frequent pulmonary
infection usually manifests radiographically as new infiltration
and occasionally by abscess formation. Pneumothorax and/or
mediastinal emphysema may be manifest in some.
insufficiency can be confirmed by special examination of stools
and pancreatic secretion. The sweat test is the simplest and
most reliable method for the diagnosis of cystic fibrosis.
If performed properly, a positive test (i.e., a sweat chloride
concentration of over 60 meq per liter in children) is diagnostic.
pulmonary function test usually shows evidence of obstructive
ventilatory impairment and hyperinflation. Vital capacity
is markedly diminished, while residual volume is increased
up to four or five times predicted normal.
greatest challenge in management of a patient with cystic
fibrosis is related to pulmonary complications. Gastrointestinal
manifestations are usually controlled by proper diet, vitamins,
and pancreatic enzymes. Despite significant advances in knowledge
and understanding of pulmonary problems in cystic fibrosis
and availability of effective therapeutic measures, patients
with this dreadful disease still succumb to pulmonary complications.
Treatment of these patients should be started very early in
the course of their disease before development of irreversible
pulmonary damage. As was indicated earlier, the common denominator
of lung lesions is obstruction of airways due to bronchial
secretions. Therefore, the principle of management will center
around the removal of these secretions and alleviation of
obstruction. The role of antibiotic in treatment of these
patients is evident from the importance of bacterial infection
in causing many of the pulmonary complications.
considering the measures for removal of mucopurulent secretions,
it should be recalled that these secretions are thick and
very tenacious; therefore, the importance of proper humidification
and other methods for their loosening should be emphasized.
Dry air and respiratory irritants should be avoided. Use of
mist tents and other methods of humidity therapy has resulted
in some success in helping to reduce sputum viscosity and
in making coughing and postural drainage more effective. However,
the argument for and against regular use of mist tents at
night continues. The results of the studies question the effectiveness
of this form of therapy. Expectorants such as potassium iodide
of glycerol guaiacolate have been commonly used with limited
results. Mucolytic and enzymatic agents, such as acetylcysteien
and pancreatic dornase, used in inhalational form, have shown
some benefit. These treatments should be followed with effective
cough and postural drainage. These maneuvers should become
part of the patients daily routine. Patients responsible
family members should be thoroughly instructed in their proper
use. Gentle chest tapping, cupping, or use of mechanical devices
may help the effectiveness of postural drainage. IPPB should
be administered with great caution.
therapy is one of the most important aspects of management
of patients with cystic fibrosis. The antibiotic is usually
given therapeutically and, occasionally, prophylactically.
Stahylococcal infection, which is the most common bacterial
infection in cystic fibrosis, should be treated with a proper
antistaph agent. Pseudomonas aeruginosa, which is frequently
isolated from the sputum of these patients, is very difficult
to eradicate despite use of potent antibiotics.
lavage with normal saline solution has resulted in variable
success in some patients with severe and life-threatening
pulmonary involvement. Surgery has been rarely considered
for resection of localized lesions to control massive hemoptysis.
Course and Prognosis
most cases of cystic fibrosis, the severity of pulmonary complications
determines the outcome. The degree of pancreatic insufficiency
has no significant effect on the ultimate outlook if properly
treated with adequate nutrition and replacement therapy. The
increase in survival from less than 2 years to about 16 years
in the past 30 years is mostly the result of early recognition
and proper treatment. Still, some patients die in infancy
or early childhood; and increasing large number survive to
ages of 20 or 30 years, occasionally even longer. Death beyond
the neonatal period is due to pulmonary complications such
as overwhelming infection, or, frequently, respiratory failure.
3. Restrictive Pulmonary Disease:
lung disease is characterized by a loss in lung volume. The
primary factor in restrictive lung disease is a decrease in
lung compliance (distensibility). This can be a result of
changes in the lung tissues (parenchyma), the chest wall,
or both. This decrease in lung compliance is usually the result
of lung inflammation, fibrotic lung disease, neoplasms, kypohoscoliosis,
and neuromuscular diseases. As a result, lung volumes are
decreased. The only single diagnostic parameter for restrictive
lung disease is a significant reduction in the total lung
in this discussion are: interstitial pneumonia, pneumoconioses,
sarcoidosis, thoracoskeletal diseases of the chest wall, neuromuscular
disorders, Pickwickian syndrome, pneumothorax, pleural effusion,
ARDS and pulmonary edema.
pneumonia is characterized histologically by alveolar wall
fibroses. These pneumonias are also known as interstitial
fibrosis, honey-comb lung, Hamman-Rich syndrome and cryptogenic
pneumonia is usually seen in a person between 20 to 40 years
of age regardless of sex or race.
About 50% of the cases of interstitial pneumonia are caused
by; Drug toxicity or hypersensitivity, ARDS, farmers
lung, connective tissue disease, sarcoidosis and genetic disorders.
The other 50% are thought to be idiopathic.
pneumonia occurs within the alveolar walls and the cells of
the alveolar lining. These are the gas exchanging tissues
of the lung. The alveolar capillaries are disrupted and the
alveolar wall increases in thickness.
are four classifications of interstitial pneumonia according
to their pathology:
1. Usual interstitial pneumonia
2. Lymphocytic interstitial pneumonia
3. Desquamative interstitial pneumonia
4. Bronchiolitis obliterans or bronchial interstitial pneumonia
patient with interstitial pneumonia will present with dyspnea
on exertion; a dry, hacking, nonproductive cough; possible
clubbing of digits; rales; and possibly cor pulmonale. Complications
associated with interstitial pneumonia are spontaneous pneumothorax
chest x-ray shows a pattern of diffuse reticular or nodular
reticular infiltrates primarily in the basilar segments of
the lung. In the advanced stages, small cystic spaces (honeycombing)
are seen. Lung volumes appear reduced. Pulmonary vascular
markings may be increased if cor pulmonale is present.
function studies will show a decrease in lung volumes with
normal flow rates. DLCO will be reduced, especially after
exercise. Static lung compliance will also be reduced.
blood gases will show hypoxemia and hyperventilation. Again,
exercise will worsen these values. The cause of hypoxemia
is due to a ventilation/perfusion mismatch rather than a diffusion
the early stages of interstitial fibrosis, the above tests
may be normal; however, with exercise, impairment is evident.
treatment of choice for interstitial pneumonia is corticosteroid
therapy. However, once the damage is done, it is usually permanent.
pneumoconioses are defined as a group of diseases characterized
by any change in the lung caused by inhaled dusts. These are
also known as occupational diseases.
various diseases in this group are classified according to
their etiology. Table 2 shows some of the pneumoconioses and
their causative factors.
Pneumoconioses and There Causative Factors
alone to a dust does not necessarily indicate occurrence of
the disease state. Many factors come into play, such as the
nature, intensity and duration of exposure; the particle size
of the dust; other irritating factors (i.e., cigarette smoking,
air pollution); pulmonary clearance; and others.
following pneumoconioses will be discussed:
2. Asbestosis pneumoconiosis
3. Talcosis pneumoconiosis
4. Berylliosis pneumoconiosis
5. Coal workers pneumoconiosis
is caused by inhalation of toxic silica dust. It is found
predominantly in people who do sandblasting, foundry work
and underground mining. Depending on the intensity of the
dust, the symptoms of silicosis may show up in as little time
as 18 months or up to 30 years.
can be divided into two categories: simple and complicated.
Simple silicosis is present without underlying lung disease
(i.e., COPD) and is usually asymptomatic. Complicated silicosis
is the more advanced stage of the disease and is usually accompanied
by parenchymal fibrosis in the form of lump-like densities.
free crystalline silica is inhaled into the lung, the toxic
particles are ingested by macrophages and destroy the macrophages.
More macrophages are produced and they too are destroyed after
ingesting the free silica particles. Eventually, silicotic
nodules are produced as the particles form collagen fibers
and hyaline membranes. As more silica particles are inhaled,
the amount of nodules increases and they begin to join together,
enlarge and form cavitations. An added complication to silicosis
presents clinically in varying degrees according to its severity.
The patient with complicated silicosis will show symptoms
of cough with expectoration, chest pain, dyspnea, wheezing
and repeated respiratory infections. The patient in the late
stages of the disease will show restrictive disease in pulmonary
function studies along with impaired diffusion studies. Hypoxemia,
pulmonary hypertension, cor pulmonale and death may ensue.
treatment of silicosis deals mainly with preventative measures.
Oxygen therapy and treatment of the congestive heart failure
can be used as supportive therapy.
is caused by the inhalation of asbestos. This has occurred
in the past in many industries, as asbestos is a commonly-used
material (e.g., insulation, brake linings). There are two
types of asbestos fibers: amphiboles and chrysolile. The amphibole
fibers are the most dangerous to the lung as they are long
and difficult for the macrophage to ingest.
inhaled, asbestos irritates the tissues causing a pulmonary
fibrosis in the terminal airways, pleura and alveoli.
symptoms of asbestosis are dyspnea and a nonproductive cough.
Roentgenographic changes may be seen in the lower lung fields
and the pleura. Pleural effusions may be present. Pulmonary
function tests indicate restrictive disease and decreased
perfusion. In patients who suffer from asbestosis and smoke
cigarettes, there is an added risk of complicating brochogenic
is thought to be caused by inhalation of talc accompanied
with tremolite fibers. Talcosis is characterized by large
fluffy densities found usually in the mid-portion
of the lung. Fibrosis may ensue and progress to the degree
of disablement. Symptoms may be relieved with steroid therapy.
can be caused by the inhalation of high concentrations of
beryllium over a short period of time. Following exposure,
symptoms do not necessarily occur rapidly; in some cases,
it may take several weeks after exposure to become symptomatic.
include acute rhinitis, pneumonitis and tracheobronchitis.
Severe hypoxemia results. Oxygen therapy and sometimes assisted
ventilation are required, but there is an 80% recovery rate
from the disease. The mortality rate is 10% and the remaining
10% of the victims of berylliosis suffer from a chronic condition.
beryllium granulomatosis is characterized by granulomata
found in the lungs and throughout the body. The exposure to
beryllium may only be slight and pass unnoticed. Susceptibility
varies between, individuals and the appearance of symptoms
may occur some time from the initial exposure. Symptoms of
chronic berylliosis include a persistent dry cough, weight
loss, severe dyspnea and sometimes fever and anorexia. Pulmonary
function shows no restrictive or obstructive component, but
diffusion is impaired markedly. Chest x-ray resembles sarcoidosis
with hilar adenopathy. The symptoms may be temporarily relieved
with steroid therapy.
Coal workers pneumoconiosis (Black Lung)
is the most common form of pneumoconiosis. It is caused by
inhalation of coal dust and is seen in coal workers. The severity
of the disease is relative to the amount of exposure.
workers pneumoconiosis has two forms: early and late.
In the early form, coal particles are seen accumulated around
the respiratory and terminal bronchioles. These small airways
are sometimes dilated and areas of focal emphysema are present.
the late form of coal workers pneumoconiosis (progressive
massive fibrosis), large areas of fibrous tissue, black with
dust, are present.
early forms are often asymptomatic unless the worker has an
underlying disease (COPD). In the later forms, the victim
presents with dyspnea possibly leading to respiratory failure.
The pulmonary function studies in the patient with the progressive
form of the disease show a mixture of obstructive and restrictive
chest x-ray shows fine nodulation and the stages of the disease
may be determined by the density of the shadows.
treatment of coal workers pneumoconiosis consists solely
of preventative and supportive measures for ensuing respiratory
is an ill-defined granulomatous disease affecting multiple
body systems. Etiology is unknown. It is found throughout
the world, predominately in women, with a high incidence in
the southeastern United States. This is an area with a high
black population, yet Sweden has almost the same rate of incidence.
sarcoid lesion (3 to 4 cm in diameter) is a noncaseating granuloma.
It is made up of epitheloid cells, giant cells and lymphocytes.
This lesion is found primarily in the lungs and on the lymph
nodes. It will either resolve uneventfully or cause hyaline
fibrosis and structural change in the target organ. In the
lung, thickening of the alveolar membrane and fibrotic changes
is difficult to picture clinically. The patient with sarcoidosis
may present with dyspnea, irritating cough, general malaise
and weight loss. Sarcoidosis can be determined with the chest
chest x-ray may show hilar lymph node enlargements with or
without pulmonary involvement. When a pulmonary abnormality
is seen, it usually has a bilateral, diffuse, ground
glass appearance and is distributed from the upper lung
fields to the bases. As the disease progresses, pulmonary
fibrosis and scaring will present.
specific skin test for sarcoidosis, the Kviem tet, can be
performed. It takes four to six weeks to determine the results.
Other tests that can be performed are the Mantoux test and
function testing will demonstrate a restrictive pattern, normal
flow rates and a decreased DLCO. Arterial blood gases may
be normal. If abnormal, there may be a slight hypoxemia.
treatment of sarcoidosis is limited to treating the acute
symptoms. In this case, an analgesic may be used. Occasionally,
steroid therapy can be helpful.
of the chest wall can also cause restrictive lung disease.
These conditions can be congenital as a result of tuberculosis
or neuromuscular disease. A backward curvature of the spine
is termed kyphosis. A lateral curvature of the spine is called
scoliosis. Kyphoscoliosis is both a lateral and backward curvature
of the spine.
disease of the chest wall which impedes the chest expansion
is termed restrictive. This is because of a moderate to severe
reduction of VC and TLC in these patients.
neuromuscular disorder that affects the respiratory muscles
or their nerve supply is classified as a restrictive disease.
Diseases falling into this category include poliomyelitis,
Guillaine-Barre syndrome, myasthemia gravis and muscular dystrophy.
diseases can cause paralysis of the accessory muscles of ventilation
and the diaphragm, causing a severe reduction of VC, TLC and
Diseases Affecting Respiration
mechanisms which respiration is affected by during neuromuscular
diseases are variables that include reduced muscular force
for adequate ventilation, disturbance of certain reflexes
important for protection of the lung from aspiration of food,
gastric content, and upper airway secretions. Mechanisms are
also affected by impairment of effective cough for clearing
of air passages, diminished or absent periodic, voluntary
or involuntary, deep-breathing maneuvers, lack of mobility
with its inherent problems, and dysfunction of the respiratory
center. Frequently, more than one of these mechanisms is involved.
this section of the lesson, we shall briefly discuss some
of the important conditions affecting these functions through
the involvement of the muscles, neuromuscular junctions, peripheral
nerves, and spinal cord.
of the Muscles
major primary muscular diseases that may involve respiratory
function are muscular dystrophies and inflammatory myopathies.
dystrophies are a group of hereditary conditions characterized
by a progressive degeneration of the striated muscles, resulting
in increasingly severe weakness. They have been classified
according to certain clinical and genetic features. The most
common form is Duchenne dystrophy, which is inherited as X-linked,
recessive trait, and therefore, is essentially a disease of
males. Other forms, which have autosomal type of inheritance,
are seen in both sexes.
onset of muscular weakness, which is the only presenting symptom
in most cases, is quite variable. In Duchenne dystrophy, the
weakness starts early in life in the proximal muscles of the
extremities. Once the child starts to walk, certain abnormalities
can be detected, which become more evident as he grows older.
Movements such as getting up from a sitting position or climbing
stairs, which require proximal muscular strength, become more
and more difficult. In early adolescence, the victim is usually
unable to walk. In other forms of muscular dystrophy, the
onset is later, and they are usually designated according
to the group of muscles that are primarily involved.
myotonic muscular dystrophy, in addition to progressive muscular
weakness, there are certain distinctive features. Difficulty
of relaxing the contracted muscles such as a hand grip, known
as myotonia, is quite characteristic. Early development of
cataract, testicular atrophy, and frontal baldness are other
complications are much more common in myotonic dystrophy than
in other forms. In addition to the difficulties related to
respiratory muscle involvement, there are frequent problems
with swallowing and aspiration. Pulmonary function studies
in most cases of muscular dystrophy demonstrate some abnormalities.
Reduced vital capacity, maximum voluntary ventilation, and
maximum expiratory and inspiratory forces are quite common.
The severity of these abnormalities depends on the degree
of respiratory muscle involvement.
infection is a common cause of death in these unfortunate
individuals. Respiratory insufficiency is frequently aggravated
by an intercurrent infection, which may result in fatal respiratory
failure. In overall management of these patients, the importance
of proper respiratory care cannot be overemphasized.
Disorders of the Neuromuscular Junction
junction of the motor nerve endings with the striated muscle
(muscle end plate) is the area through which the nerve impulses
are transmitted to the muscle. This transmission is accomplished
by liberation of acetylcholine from the nerve ending and its
reaction with the special receptor at the muscle cell membrane.
This interaction results in increased permeability of this
membrane to such cations as sodium, potassium, and calcium.
The crossing of these ions through the membrane results in
depolarization of muscle and initiation of its action potential
and contraction. An enzyme, called acetylcholinesterase, inactivates
acetylcholine by hydrolysis; thus the muscle is repolarized
and becomes ready for reception of another nerve impulse and
initiation of another contraction. The proper function of
this junctional region is, therefore, essential for orderly
Certain agents are known to disrupt the normal function of
the neuromuscular junction. Drugs that interfere with the
action of enzyme acetylcholinesterase (e.g. neostigmine) result
in accumulation of acetylcholine in this region, thus facilitating
the transmission of impulses through the myonerual junction;
but large doses of these drugs will result in muscle weakness.
On the other hand, neuromuscular blocking agents paralyze
the muscles by blocking the access of acetylcholine to the
motor end plate. Tubocurarine and other curare-form drugs,
such as Pavulon, act through this mechanism. Succinylocholine
(Anectine), another type of paralyzing agent, causes depolarizing
of muscles as acetylcholine, but is inactivated much more
slowly. Repolarization, which is essential for transmission
of impulses from the nerve endings, is there- fore prevented.
These paralyzing agents are used as an adjunct in general
anesthesia and for facilitation of management of patients
undergoing intubation and mechanical ventilation.
botulism (a form of food poisoning from absorption of a toxin
produced by a bacterium, Clostridium botulinum) the paralysis
is due to the effect of the toxin on the nerve endings, preventing
them from releasing acetylcholine. Rapid ventilatory failure
due to respiratory muscle paralysis is the usual cause of
death in botulism.
A certain group of antibiotics, such as kanamycin, gentamycin,
neomycin, and streptomycin, may result in neruomuscular blockade
by interference with the release of acetylcholine.
gravis is a disease of the neuromuscular junction manifested
by a muscular weakness and fatigability. The exact cause and
pathogenesis have not been clearly understood, however, immunology
seems to play an important role in this disease. Recent studies
suggest the production of autoantibodies against the acetylcholine
receptors in the muscle-cell membrane. The relationship of
the thymus gland and myasthenia gravis has long been demonstrated;
70 percent of the patients have hyperplasia of this gland
and another 10 percent have thymoma (neoplasm of the thymus).
frequently involved are the muscles of the face, eyes, pharynx,
and larynx. However, every skeletal muscle may be affected.
Involvement of the respiratory muscles may result in abrupt
development of ventilatory failure. This grave complication
is the most common cause of death from this disease.
gravis occurs at all ages; females are affected more often
than males. The highest incidence is during the third decade
onset of myasthenia gravis is usually slow and insidious,
but occasionally it may be abrupt. Weakness of the eye muscles,
which is the most common manifestation, may result in drooping
of the eyelids and double vision. Characteristic facial appearance
results from the involvement of the facial muscles. Abnormal
speech may be due to weakness of facial, tongue, or laryngeal
muscles. These symptoms are more apparent at the end of the
day or following repetitive movements of the involved muscles,
and they improve with rest. Difficulty with chewing, swallowing,
and choking upon eating, causes problems with nutrition. Excessive
fatigability of muscles of the trunk and extremities can be
demonstrated with exercise. Sometimes the weakness may be
extreme, and the patient may seem to be totally paralyzed.
crisis refers to the rapid development of weakness to the
extent of impairment of respiration. It is usually provoked
by infections, especially those involving the respiratory
tract. Emotional upset, surgery, discontinuation of medications,
or the intake of certain drugs known to increase neuromuscular
blockade are other causes of myasthenia crisis. A similar
picture may develop in patients who have taken an excessive
amount of anticholinesterase drugs.
The course of myasthenia gravis is usually unpredictable;
it may progress rapidly or slowly, remain unchanged, or remit
spontaneously. Certain factors, such as infection, general
fatigue, lack of sleep, menstrual period, or other causes
of physical or mental stress, may aggravate its course. Respiratory
complications as a result of impairment of respiratory muscle
function, difficulty with clearing the secretions, aspiration,
and frequent respiratory-tract infections are continuous threats
to these patients.
of myasthenia gravis is strongly suspected by the characteristic
history and usually made by demonstration of muscular weakness
and fatigue upon repetitive or sustained contraction of certain
muscles, particularly the eye muscles. Regaining of strength
after a period of rest further supports the diagnosis. With
the administration of certain anticholinesterase drugs such
as neostigmine or , preferably, edrophonium chloride (Tensilon),
regaining of strength can be demonstrated in dramatic fashion.
This test is also useful in differentiating the weakness of
myasthenia from that of excessive anticholinestrase therapy.
characteristic muscle fatigability can also be demonstrated
by electric stimulation of muscles and recording their response
treatment of patients with myasthenia gravis has undergone
significant changes in recent years; however the principles
of management remain essentially the same. These include proper
and adequate treatment of acute episodes of severe muscle
weakness, including myasthenia crisis, and measures directed
to alter the basic pathophysiologic process and prevent the
recurrence of symptoms.
almost every patient with myasthenia gravis is hospitalized
for further studies, observation of the course of the disease,
and evaluation of the response to treatment. More severely
involved patients are usually put in the intensive care unit.
Diligent respiratory care is the most important part of the
management of these patients during the acute phase of their
illness. Unpredictability of the progress of the disease requires
frequent and regular monitoring of the patients respiratory
function, such as measuring inspiratory and expiratory pressures.
They should be closely watched for problems such as difficulty
with swallowing, aspiration, and clearing the airways. Infections
should be detected early and treated properly. Tracheostomy
is usually preferred to endotracheal intubation for this purpose.
An occasional patient may need prolonged ventilatory support.
main pharmacologic agents in treatment of acute attacks are
anticholinesterase drugs, especially pyridostigmine (Mestinon)
or sometimes meostimine, which result in significant improvement
in most cases. Difficulty with arriving at a proper maintenance
dosage, variability in response, and occasional development
of refractoriness make these agents less than ideal for continuous
long-term therapy. However, less severe cases can be managed
safely with these agents. Mild forms may relapse. Corticosteroids,
particularly predniosne, given in large single dose every
other day, have been demonstrated to result in remission of
cases that respond poorly to other forms of therapy.
of the thymus gland (thymectomy) has been performed regularly
in many centers as the treatment of choice. Although the result
of surgery of the thymona is less than satisfactory, the majority
of the patients with thymic hyperplasia show long-term benefits
from thymectomy. In recent years, transcervical approach for
removal of the thymus gland has been adopted by many surgeons.
This method has obviated the need for thoracotomy, which has
significant operative and postoperative morbidity and mortality
in patients with myasthenia gravis.
Diseases of Peripheral Motor Nerves: Guillain Barre
nerves maybe affected by various toxic agents, metabolic disorders,
inflammatory states, vascular disease, trauma and other unknown
sources. Despite frequency of peripheral nerve disease in
clinical practice, involvement of the respiratory motor nerves
is very uncommon or insignificant. However, a form of acute
polyneuritis, known as Guillian-Barre Syndrome, frequently
involves the respiratory muscles, resulting in ventilatory
difficulties. The cause of death in this disease, almost often
is due to respiratory complications.
syndrome is a relatively common condition, which has its highest
incidence in the young and middle-aged. There is frequently
a history of preceding upper respiratory tract infection,
although the etiology remains unknown. Its association with
certain viral diseases, including infectious mononucleosis,
has been demonstrated in some cases. Pathologically, there
is segmentation of the myelin sheath of the peripheral nerves
and mononuclear cell infiltration. Delayed hypersensitivity
against the myelin sheath has been implicated in its pathogenesis.
the onset is rapid with progressive, more or less symmetrical,
weakness, starting in the legs and spreading upward to affect
the trunk, arms, and face. It may, however, start in the face
or upper extremities. Respiratory muscles are involved in
more severe cases. The paralyzed muscles are flaccid. Sensory
changes may also be present. After the establishment of maximum
weakness, which is quite variable in individual cases, spontaneous
recovery begins. This is usually expected with 3- 4 weeks.
Delayed onset of remission often results in incomplete recovery.
A certain form of the disease may have a chronic relapsing
Involvement of the muscles of the pharynx and larynx may result
in swallowing difficulty and aspiration. Weakness of the abdominal
and chest muscles impairs the cough mechanism, and, thus,
airway clearance, predisposing the patient to respiratory
infection and atelectasis. Other respiratory muscles, including
the diaphragm, may be affected. Vetilatory failure is expected
under these circumstances.
management of patients with Guillain- Barre syndrome
is primarily respiratory. These patients should be hospitalized,
preferably in an intensive- care unit, and proper respiratory
care given. This includes regular monitoring of the respiratory
function, with frequent measurement of vital capacity and
maximum inspiratory and expiratory pressures, careful broncho-pulmonary
toilet, and ventilatory assistance. These patients recoveries
will depend on adequate maintenance of their respiratory status;
therefore, the importance of respiratory care in their management
cannot be overstressed.
there is evidence of respiratory difficulty, as judged by
significant reduction in vital capacity and respiratory forces,
and other signs of ventilatory failure; mechanical ventilatory
support should be instituted. Tracheostomy is the preferred
mode of intubation for this purpose. As the vast majority
of patients will eventually recover despite marked impairment
of their muscle function, every effort should be made to support
their lives until remission takes place. The respiratory therapists
and nurses play crucial roles in this rewarding endeavor.
An occasional patient may require prolonged mechanical ventilation
before any sign of improvement can be demonstrated. Definite
beneficial result from the use of corticosteroids in this
disease has not been unequivocally demonstrated. The most
important and essential measure is still supportive therapy,
particularly maintenance of adequate respiration until remission
Disorders of the Spinal Chord
anterior poliomyelitis, commonly known as polio, used to be
the most important cause of ventilatory failure of neruomuscular
origin. Fortunately, it is now almost totally eradicated,
and its importance has become historical. A catastrophic epidemic
of poliomyelitis, which occurred in 1952 in Copenhagen, was
an important impetus in the movement of mechanical ventilators.
The ventilators continued to improve, while poliomyelitis
continued to vanish.
other diseases of the spinal cord may occasionally result
in respiratory difficulty. Diseases such as amyotrophic lateral
sclerosis, multiple sclerosis, and various forms of inflammatory
or neoplastic diseases of the spinal cord may result in respiratory
muscle weakness and ventilatory failure. As the origin of
the phrenic nerves is from the high cervical cord, diseases
that involve only the lower regions spare this important inspiratory
muscle, and adequate ventilation is maintained. However, significant
weakness of other respiratory muscles, especially abdominals,
may result in impairment of effective cough, and, thus, cause
injury to the cervical spinal cord below the fourth cervical
vertebra results in quadriplegia with maintenance of respiration
by the unaffected diaphragm. Injury above this level, however,
will result in complete respiratory paralysis. Even with intact
diaphragmatic function, quadriplegics are predisposed to respiratory
difficulties from frequent bouts of pneumonia and atelectasis
as a result of impairment of cough and clearing the airways,
as well as a lack of mobility. In addition, these patients
are prone to develop thrombophlebitis and repeated pulmonary
embolism. Most early deaths following acute traumatic quadriplegia
are due to pulmonary complications; therefore, the importance
of adequate respiratory care in management of such patients
should be stressed. Continuous respiratory care should be
included in overall chronic management and rehabilitation
of these unfortunate patients.
Pickwickian syndrome is a term applied to excessive obesity
which restricts the movement of the chest wall. Tissue mass
alone causes the patient to hypoventilate.
patients present with cyanosis, polycythemia, hypoxemia, hypercapnia,
pulmonary hypertension and often cor pulmonale. These patients
may complain of somnolent episodes and nocturnal apnea.
Treatment of the Pickwickian patient involves ventilatory
support and weight loss. This can be achieved with proper
diet, counseling and much work on the part of the patient.
pneumothorax is caused by air entering the pleural space causing
the lung to partially or totally collapse. The degree of collapse
is quantitatively assessed as a percentage (e.g., 30% pneumothorax,
50% pneumothorax). Air can enter the pleural space either
through the chest wall, such as with a penetrating injury,
or from the lung as occurs when a bleb or bullae ruptures.
spontaneous pneumothorax occurs when there is a rupture of
visceral pleura without evidence of pulmonary disease. An
open pneumothorax indicates that a free flow of air exists
in and out of the pleural space with each ventilation. A closed
pneumothorax is one in which there is no air movement. A tension
pneumothorax is described as one in which air enters the pleural
space during inspiration and cannot escape during exhalation.
most common type of pneumothorax is the spontaneous pneumothorax.
It is usually cased by rupture of a bleb, bullae or a weakened
area in the lung periphery. Disease in which these pathologies
are common are chronic obstructive lung diseases, status asthmaticus
and end-state sarcoidosis.
pneumothorax is often seen in young males between twenty and
forty, particularly those who are tall and thin. This is thought
to be due to an increased stress to the upper lung fields.
pneumothoraces usually occur while the patient is in a resting
state, rather than with the strain and increased physical
effort as would be expected.
pneumothrorax is also caused when there is penetration through
the chest wall and the visceral pleura. This type of pneumothorax
can be caused by rib fractures, stab wounds, gun-shot wounds,
thoracotomy procedures, thoracentesis, transthroracic needle
biopsy or similar events.
the intrathoracic pressure (within the pleural space) is negative
and less than the intrapulmonary pressure (within the airways).
When a pneumothorax occurs, this pressure gradient slowly
or rapidly decreases. If collapsed lung tissue does not block
the source of the pneumothorax, the pressure gradient can
reach zero. If a tension pneumothorax occurs and air enters
the space on inspiration through a valve-like
opening but cannot escape on expiration, the pressure within
the pnuemothorax can increase enough to compress the opposite
lung by a mediastinal shift.
major clinical features of pnuemothorax are dyspnea, chest
pain on the affected side, a decrease in chest expansion,
distant or absent breath sounds and hyper-resonance. In addition,
there may be subcutaneous emphysema over the neck and chest;
in the tension
pnuemothorax, hyperdistention of the thorax and cyanosis may
occur. If any or all of these signs are present and a pnuemothorax
is suspected, a chest x-ray should be taken
immediately to assess the presence or absence of a pneumothorax.
The patient with COPD may normally exhibit these signs, especially
in the presence of a respiratory infection. If the pnuemothorax
is small, it can be difficult to clinically diagnose. For
this reason, the chest x-ray is an important tool in the diagnosis
of a pneumothorax.
chest x-ray confirms the diagnosis of pneumothorax, regardless
of its cause. A P-A film will show the area of collapsed lung
accompanied by a peripheral area of translucency bordered
by the visceral pleural line. The translucent area is caused
by the air in the pleural space.
the pneumothorax is large, the trachea and mediastinum will
shift away from the affected side. The hemidiaphragm on the
affected side may be depressed. A small pneumothorax can be
more difficult to identify due to the presence of skeletal
shadows, which can obliterate the line of the visceral pleura.
symptoms of the pneumothorax that can be determined by arterial
blood gases are hypoxemia and hypocapnia. Hypoxemia may occur
from the interruption of gas exchange, which could cause the
patient to hyperventilate with a resultant hypocapnia. A pulmonary
function test will show a reduction of FVC and FC.
treatment of a pnuemothorax is to re-expand the lung and prevent
further pnuemothoraces. A small, spontaneous pnuemothorax
(less than 20%) can resolve itself. With sufficient rest,
the body can fully reabsorb the air in the pleural cavity.
Serial chest x-rays must be performed to monitor progress
and spot a recurrent pneumothorax.
tension pneumothorax is considered a medical emergency and
must be treated immediately with the introduction of a large-bore
needle into the pleural space. If positive pressure exists
in the pleural space, a rush of air will exit upon insertion
of the needle. The needle should be replaced with a chest
tube connected to underwater seal drainage.
chest tube permits air to leave the pleural space and prevents
additional air from entering. In this way, pleural pressures
can return to normal and the lung is allowed to re-expand.
When the lung is fully expanded, the suction is discontinued
and the tube is clamped. This allows assessment of the pleural
space for normal function prior to removal of the tube. When
the lung is capable of remaining re-expanded without the use
of a chest tube, the tube is removed and the incision covered
tightly with a bandage and allowed healing.
pneumothorax greater than 20% should be treated with the use
of a chest tube for re-expansion. This is especially true
in the pneumothorax that causes dyspnea. The tube should remain
in place at least 24 hours and then until re-expansion is
pleural effusion is the presence of fluid rather than air
in the pleural space. This is a common occurrence usually
seen in conjunction with another disease entity.
pleural effusion is caused by fluid passing across the pleural
membrane due to the hydrostatic and osmotic pressure grandients
across the membrane. Examples of pleural effusion are empyema
(pus in the pleural space), hemothorax (blood in the pleural
space) and chylothorax (lymph in the pleural space).
nature of the pleural fluid can be determined through aspiration
and laboratory analysis. The types of fluid can be divided
into transudates (having few cellular elements) and exudates
(having more cellular elements), according to the protein
content. A transudative effusion can be formed with congestive
heart failure, cirrhosis and the nephrotic syndrome. A transudative
effusion is a localized tendency for edema fluid to form.
exudative effusion can result if the pleural membranes are
irritated. This type of effusion can occur with lung infections,
pneumonia, lung abscess, fungal diseases, tuberculosis and
is commonly due to pneumonia or lung abscess. It is defined
as purulent fluid in the pleural cavity. Hemothorax usually
is caused through chest trauma, and subsequent hemorrhaging
into the pleural space.
chylothorax is due to a leakage of chyle (lymph) into the
pleural space. This can be due to blockage of the thoracic
duct or trauma.
there is a large effusion, the patient will complain of dyspnea
and pleuritic pain. There will be a dullness to percussion
over the effusion, absent breath sounds and a decreased movement
of the chest wall. The symptoms of a pleural effusion will
vary with the extent of the effusion.
upright chest x-ray can be used to diagnose a pleural effusion.
It will appear as a shadow which fills the costophrenic angle.
If the effusion is large, a triangular shadow will appear,
lying against the lateral chest wall.
the presence and location of a pleural effusion is detected
by chest x-ray, a diagnostic thoracentesis can be performed.
The pleural fluid is then analyzed for type of fluid and its
origin is determined. If the cause of the effusion is known,
such as in congestive heart failure, this invasive procedure
may be omitted.
the effusion is large enough to cause dyspnea, hypoxemia and
hypocapnia can be present. A pulmonary function test would
show a reduction of FVC and VC.
treatment for a pleural effusion should deal with determining
the cause of the effusion and treating the underlying disease.
Occasionally, if the pleural effusion impairs lung function
enough to cause dyspnea, a thoracentesis can be performed
to evacuate the fluid from the pleural space.
(Acute) Respiratory Distress Syndrome (A.R.D.S.):
Respiratory Distress Syndrome is a term which refers to a
collection of clinical, physiologic and pathologic features
occurring in the setting of an acute injury or illness. The
initial lung injury damages the pulmonary capillary endothelium,
stimulating platelet aggregation and intravascular thrombus
formation. Platelets release substances that attract and activate
neutrophils. Other chemotactic factors include endotoxin,
present in sepsis, a common cause of A.R.D.S., tumor necrosis
factor and interleukin-I (IL-1). Endothelial damage also initiates
the complement cascade simulating neutrophil activity and
the inflammatory response. The role of neutrophils is central
to the development of A.R.D.S. Activated nutrophils release
a battery of inflammatory mediators, including proteolytic
enzymes, toxic oxygen, arachidonic acid metabolites (prostaglandins,
thromboxanes, leukotrienes), and platelet-activating factor.
These mediators extensively damage the alveolcapillary membrane
and greatly increase capillary membrane permeability. This
allows fluids, proteins, and blood cells to leak from the
capillary bed into the pulmonary interstitium and alveoli.
The resulting pulmonary edema and hemorrhage severely reduces
lung compliance and impairs alveolar ventilation. Mediators
released by neutrophils and macrophages also cause pulmonary
vasoconstricion. Pulmonary hypertension results, and because
vasoconstriction occurs to varying degrees in the vascular
beds, V/Q mismatching occurs.
syndrome has been described as a distinct form of diffuse
pulmonary injury of various causes, characterized by rapidly
progressive dyspnea, tachypnea, refractory hypoxemia, diffuse
pulmonary infiltration, and reduced lung volumes and compliance.
This generalized inflammatory response results from the soft
tissue damage followed by an episode of hypotension. The sympathetic
response to systemic hypotension is pulmonary vasoconstriction.
Subsequent vigorous fluid resuscitation is required to maintain
systemic permeability (noncardiogenic pulmonary edema), a
decrease in pulmonary compliance and a widening of the Alveolar-arterial
gradient. On average, the amount of extravascular water in
the lungs of patients with A.R.D.S. is about three times the
upper limit of normal (which is approximately 500 ml.) but
may be as much as six to eight times the upper limit.
changes are a collection of atelectasis, interstitial and
alveolar edema, and hemorrhage, and sometimes, hyaline membrane
formation. Regardless of how it started, the ensuing events
result in more or less similar pathologic and physiologic
alteration of the lungs. Both endothelium and epithelium are
damaged resulting in leaky alveolar capillary membrane. As
part of the host defensive response and reparative effort,
local and systemic inflammation develops. The inflammatory
reaction itself causes further lung injury.
ACUTE LUNG INJURY AND/OR A.R.D.S:
IF WE ARE TO INCREASE OUR SURVIVAL RATE IN THIS PATIENT
POPULATION, EARLY INTERVENTION IS IMPERATIVE.
conditions that result in lung injury directly, inflammation
is secondary, whereas in sepsis the lung injury is the consequence
of inflammation. Sepsis, which is the most common cause of
ARDS, is defined as the systemic inflammatory response to
infection that may be local or systemic (septicemia). Among
the infectious agents, gram-negative bacteria are notorious
for inciting severe systemic reaction. Endotoxin produced
by these microorganisms is a major reason for their characteristic
pathogenic features. In addition to infection, other clinical
conditions may also result in systemic inflammatory response
syndrome (SIRS). They include multiple trauma, extensive burn,
acute pancreatitis, and shock from noninfectious causes. When
severe enough, SIRS affects the function of several organs
including the lungs (multiple-organ dysfunction syndrome)
and may even cause their failure (multiple-organ system failure).
Lung injury and A.R.D.S. almost always represent the predominant
feature of these events.
According to the European- American Consensus Conference on
A.R.D.S. (1994) the following working definitions were developed.
Since both conditions involve impaired oxygenation, defined
as a ratio of the partial pressure of arterial oxygen to the
fraction of inspired oxygen, and since RESPIRATORY THERAPY
IS A SCIENCE, the following components are useful in establishing
an operational definition:
infiltrates on CXR
Pulmonary capillary wedge pressure
less or equal to 18 mm.Hg.
And calculation of the PAO2/ FIO2
a patient has a high pulse rate, he or she is ANXIOUS. One
of the classic signs of refractory hypoxemia is tachypnea
and TACHYCARDIA accompanied by a clear chest film. If you
encounter a trauma patient who has a rapid pulse:
1. COMPUTE A-a DO2
2. If the patient is on a ventilator,
compute the patients compliance
the patient has a PaO2/FIO2 of <300
the patient for Acute Lung Injury
the patient has a PaO2/FIO2 of <200
the patient for A.R.D.S.
the exact mechanism is unclear (toxic molecules including
oxygen radicals/ proteases), A.R.D.S. is a complex inflammatory
response, there is evidence that overall survival has improved
in recent years due, in part, to early intervention.
as a primary cause of or contributing factor in A.L.I, inflammation
has been regarded as the major pathogenic mechanism in ARDS.
Despite extensive animal and human research in recent years,
the exact mechanisms of lung injury by various inflammatory
cells and mediators are not fully understood. Although many
inflammatory cells and mediators of lung injury have been
recognized, their exact role, the sequence of their involvement,
and the degree of their importance have remained speculative.
Among the cells involved, polymorphonuclear neutophils (P.M.N.s)
play the central role in inflammation. They are sequestered
in pulmonary microvasculature; become activated; and produce
various proteolytic enzymes, toxic oxygen metabolites, and
other inflammatory mediators. Other cells that participate
in the process are macrophages, lymphocytes, and fibroblasts.
They interact with the help of cytokines and produce various
mediators of inflammation. Complement activation, involvement
of coagulation factors, and participation of certain vasoactive
substances (including nitric oxide), have also been considered
to be important components of the pathogenic process in A.L.I.
resulting from the initial event and sustained by subsequent
inflammation is the basic mechanism of structural change and
a functional impairment characteristic of A.R.D.S. In addition
to accumulation of fluid and inflammatory cells in the lungs,
other changes also take place. As a result of injury to alveolar
cells and presence of edema fluid in the alveoli, surfactant
is markedly reduced and becomes qualitatively abnormal. Some
of the small vessels are obliterated from fibrin-platelet
aggregation. Certain growth factors released by inflammatory
cells results in early proliferation of fibroblast and beginning
fibrosis tissue formation.
the underlying etiologic factors are quite varied, pathologic
changes are almost similar. Diffuse alveolar damage with resultant
changes secondary to alveolar-capillary leak and inflammatory
reaction are the bases of morphologic abnormalities as seen
in the lungs of patients with A.R.D.S. Early acute changes
include destructive lesions and loss of endothelial and Type
1 alveolar epithelial cells, edema, hemorrhage, infiltration
with inflammatory cells, microatelectasis, and hyaline membrane
formation. These changes are not homogeneous; whereas some
alveoli are severely damaged or filled with proteinaceous
fluid and cells, others may be more or less intact. Pathologic
lesions have a predilection for chronic changes of the organizing
stage, in which Type II alveolar cells proliferate. Increased
numbers of fibroblasts denote the beginning of fibrosis that
may develop rapidly. At this stage, there are also changes
in pulmonary microvasculature characterized by disruption
of the vascular bed and thrombotic or embolic occulsion of
some of the small vessels. Bronchoalveolar lavage (B.A.L.)
fluid recovered from patients with A.R.D.S. contains large
numbers of P.M.N.s. B.A.L. fluid surfactant is deficient in
its surface- tension lowering activity as a result of its
hypoxemia, an essential component of A.R.D.S., is the result
of marked maldistribution of ventilation and perfusion and
their mismatching. Intrapulmonary shunting from perfusion
of unventilated lung regions is the hallmark of pathophysiologic
change of the syndrome. Alveolar and interstitial edema, inflammatory
changes, reduced and ineffective surfactant, and early fibrotic
changes are known causes of reduced lung compliance. Considering
the heterogeneity of lung injury, however, decreased compliance
may be in large part from reduced volume of ventilating lung
units. Such units, per se, may have normal compliance. This
notion is important for understanding the deleterious effect
of mechanical ventilation with large tidal volumes in A.R.D.S.
of vascular disruption and obstruction of some of the small
vessels, certain ventilated lung units may have reduced or
no perfusion resulting in increased dead-space ventilation.
High minute ventilation, together with reduced lung compliance
markedly increases the work of breathing. Tachypnea is the
result of increased minute ventilation and low tidal volumes.
Pulmonary hypertension, a common occurrence in A.R.D.S., is
secondary to vascular obstruction and increased vascular tone
from imbalance of vasoactive susbstances and hypoxemia.
initial assessment of arterial blood gas analysis will usually
reveal respiratory alkalosis and varying degrees of hypoxemia.
The hypoxemia is often relatively resistant to supplemental
oxygen (refractory hypoxemia). As alveolar fluid accumulates,
hypoxemia continues to worsen and mechanical ventilatory support
becomes necessary. After a latent period of 24 or more hours,
fluffy alveolar infiltrates develop and are visible on the
chest roentgenogram, and arterial blood gas analyses show
progressive hypoxemia due to a shunt-like effect. Pulmonary
compliance progressively falls. According to the European-American
Consensus Conference on A.R.D.S. (1994) the following working
definitions were developed. Since both conditions involve
impaired oxygenation, defined as a ratio of the partial pressure
of arterial oxygen to the fraction of inspired oxygen. The
following components are useful in establishing an operational
definition: (a) Bilateral infiltrates on frontal CXR, (b)
Pulmonary capillary wedge pressure less or equal to 18 mm.Hg.
and (c) calculation of the PAO2/ FIO2 ratio. If a patient
has a high pulse rate, or he or she is anxious, refractory
hypoxemia should be considered. One of the classic signs of
refractory hypoxemia is tachypnea and tachycardia accompanied
by a clear chest film. If one encounters a trauma patient
who has a rapid pulse, compute the patients A-a DO2.
If the patient is on a ventilator, compute the patients
pulmonary compliance. If the patient has a Pa02/FIO2 of <300,
treat the patient for Acute Lung Injury. If the patient has
a PaO2/FIO2 of <200, treat the patient for A.R.D.S Although
the exact mechanism is unclear (toxic molecules including
oxygen radicals/ proteases), A.R.D.S. is a complex inflammatory
response, which requires early assessment and intervention.
There is evidence that overall survival has improved in recent
years due, in part, to both early intervention and technological
pancreas is unique in that it has both endocrine and exocrine
functions. The endocrine pancreas secretes hormones: insulin,
glucagon, somatostatin, and pancreatic polypeptide. Arterial
blood is supplied to the pancreas by branches of the celiac
and superior mesenteric arteries. Venous blood leaves the
head of the pancreas through the portal vein, with the body
and tail being drained through the splenic vein. All hormonal
pancreatic secretions also pass through the portal vein to
the liver. Acute pancreatitis is a clinical syndrome resulting
from inflammation and destructive autodigestion of the pancreas
and peripancreatic tissues. Clinically, acute pancreatitis
is a common and important cause of upper abdominal pain, nausea,
vomiting, and fever. Laboratory findings of marked elevations
of serum amylase and lipase help to differentiate it from
other entities causing these symptoms. The severity of inflammation
varies, and the prognosis ranges from mild, and self-limiting
illness lasting 1 to 2 days to death from pancreatic necrosis,
hemorrhage or sepsis. Pleuropulmonar complications of acute
pancreatitis include pleural effusion, pulmonary edema, and
acute repiratory distress syndrome. Characteristically, the
pleural fluid is an exudate with high protein, LDH, and amylase
levels (normal serum amylase = 60-180 Somogyi units/ml. and
normal serum lipase = 1.5 Somogyi units/ml.)
ACUTE LUNG INJURY + VOLUME = VOLUTRAUMA
its introduction into clinical practice more than 40 years
ago, mechanical ventilation has utilized large tidal volumes
(10 to 15 ml./Kg.) to prevent the development of progressive
atelectasis and hypoxemia that was routinely seen with physiological
tidal volumes (5 to 7ml./Kg.). Recent insights into the pathophysiology
of acute lung injury has led to changes in routine approaches
to mechanical ventilation.
alterations in the anatomy and function of the lung are characteristic
of lung injury. Experimental evidence strongly suggests that
traditional approaches to mechanical ventilation with high
airway pressures produce insidious physiologic and morphologic
changes in previously normal lungs.
This process, termed VOLUTRAUMA, impedes lung healing and
may extend damage to previously unaffected areas. This realization
has led to a strategy that is designed to avoid tidal volume
collapse using physiologic transalveolar pressures while allowing
alveolar hypoventilation and hypercapnia. Debate continues
regarding the risks and benefits of pressure-limited versus
volume-limited mechanical ventilation to achieve this goal.
Research is ongoing regarding the role and techniques for
non-conventional methods of cardiorespiratory support for
this severely ill group of patients. The alterations which
ultimately produce acute lung injury can progress to multiple
Mechanical ventilation with high peak inspiratory pressures
and large tidal volumes in normal rats produces pulmonary
edema associated with severe permeability alterations, increased
filtration and diffuse alveolar damage. It has also been demonstrated
that lung overdistention, not the elevated airway pressures,
is the responsible factor for these findings, because negative-pressure
ventilation with excessively large tidal volumes will produce
similar injury. This finding was further confirmed by the
demonstration that tidal volume limitation via thoracoabdominal
binding during high-pressure ventilation inhibits the development
of permeability changes and edema. These experiments led to
the evolution of the concept that mechanism of high- pressure
ventilation inhibits the development of permeability changes
and edema. These experiments led to the evolution of the concept
that the mechanism of high pressure pulmonary edema
and lung injury is due to barotrauma, to VOLUTRAUMA.
It appears that end-inspiratory volumes are the primary determinant
of volutrauma, and thus measures to decrease pressure- volume
swings and high flow rates may not prove sufficient to protect
the lungs from ventilator induced injury.
OXYGEN IS THE FUEL OF THE BODY
chest x-ray will show diffuse alveolar infiltrates in a honeycombed
pattern in the later stages of ARDS. Early in the onset of
ARDS, the chest film can appear normal.
severe hypoxemia and an eventual hypercapnia (as the patient
tires) will be seen. Pulmonary artery wedge pressure will
be normal or high FRC will be decreased. Peak airway pressures
on the mechanical ventilator will steadily rise as compliance
involves supportive measures with oxygen therapy, fluid management
and steroid therapy.
edema is a term given to a condition where fluid collects
in the extravascular spaces and lung tissues.
edema is considered a complication of another disease entity.
Etiology of pulmonary edema involves an interruption of the
delicate pressure gradients across the alveolar capillary
membrane. Included in these causes are myocardial infarction,
mitral stenosis, fluid overload, oxygen toxicity, radiation,
silicosis, rapid removal of pleural effusion or pneumothorax,
over-transfuction, hypo-proteinemia, high altitude and heroin
pathophysiology varies with each causative agent, but the
alveolar-capillary (a-c) membrane is generally disturbed by
one of the following:
An increase in capillary hydrostatic pressure
2. An increase in capillary permeability
3. Lymphatic insufficiency
4. A decrease in interstitial pressure
5. A decrease in colloid osmotic pressure
of these disturbances of the delicate alveolar-capillary membrane
can cause fluid to leak out of the capillary into the interstitium
will be shallow and rapid and the patient will complain of
dyspnea. Orthopnea is often present along with paroxysmal
nocturnal dyspnea and Cheyne-Stokes respirations. A dry cough
may present. In acute pulmonary edema, frothy pink sputum
may be expectorated or aspirated from the trachea. The chest
wall will reveal diffuse fine inspiratory rales. There will
be an increase in tactile fremitus.
common sign of pulmonary edema is cardiomegaly and increased
vascular markings. Short horizontal lines (Kerley lines) may
appear in the lower lung fields. Blotchy shadowing will radiate
from the hilar areas in acute pulmonary edema.
will be present with a normal or low carbon dioxide level.
Pulmonary function studies would indicate an increased elastance,
airway resistance and a decreased compliance.
edema involves treatment of the underlying cause. Oxygenation
must be supported. If the underlying disease involves fluid
overload, the patient is diuresed. If the underlying problem
involves hypo-proteinemia of the blood, albumin is given.
4. Infectious Pulmonary Disease:
infectious pulmonary diseases are inflammatory processes brought
about within the lung by the introduction of an infectious
pathogen. The pathogenic agent can be bacterial, viral or
fungal. Included in this discussion are pneumonias, pulmonary
fungal infection and pulmonary tuberculosis. Treatment of
all these diseases involves identification and control of
the invading organism.
is defined as an acute inflammation of the lung parenchyma.
Pneumonia can be grouped into two major categories according
to the etiologic agent: bacterial or non-bacterial (atypical).
The non-bacterial pneumonias include mycoplasm pneumoniae,
adenovirus pneumonia and psittacosis. Most pneumonias are
of the bacterial type, acute in onset and associated with
alveolar filling by exudate.
pneumonias are classified according to their etiologic agent
and the area of involvement on the chest x-ray examination
(e.g., bronchopneumonia, interstitial, alveolar or lobar).
primary infecting agents in bacterial pneumonia are Streptococcus
pneumoniae (pneumococcus), Staphylococcus pyogenes (Staphylococcus)
and Klebsiella pneumonia (Friedlanders bacillus). Less
frequently encountered are Streptococcus pyogenes and Hemophilus
pneumonia is usually found in middle-aged to elderly patients.
Pneumonia tends to strike debilitated patients or those with
pre-existing illnesses. Several predisposing factors to bacterial
pneumonia include chronic airway infection, viral infections
of the upper respiratory tract, aspiration, or anything that
lowers an individuals resistance to infection.
transmission of the bacterial infecting agent is usually by
inhalation into the lung. Less commonly, the infection is
spread through the blood from an infection elsewhere in the
body. An inflammatory reaction occurs, usually in a large
bronchus. The infection can spread through a lobe or segment
to the lung periphery. Bacterial pneumonias are usually lobar
or segmental. If the infection is limited to the
bronchus and the airways, it is termed bronchopneumonia.
inflammatory reaction consists of local vasodilation followed
by production of an exudative fluid which fills the surrounding
alveoli and small airways. If an area of the lung becomes
filled with fluid and contains no air, it is called a consolidated
area; if the tissue begins to necrose, a lung abscess may
form; if the inflammation reaches the pleura, a pleural effusion
may form; and if the infection reaches the bloodstream, septicemia
may result. Leukocytes and macrophages appear and remove the
bacteria and debris by ingestion. Once the causative agent
(bacteria) is removed, the inflammation will eventually cease
and the pneumonic process will clear. However, some localized
complications may result (e.g., fibrosis, lung abscess and
bronchiectasis) due to lung injury.
symptoms of bacterial pneumonia and non-bacterial pneumonia
are similar, although a specific infection may present with
a certain group of symptoms.
patient with pneumonia will present with an acute onset of
malaise, fever, chills, sweating, shivering, pleuritic chest
pain, a productive cough, hemoptysis, headache and dyspnea.
The pleuritic pain is often localized to the site of the inflammation.
patient will be tachycardiac, tachypnic and febrile. The skin
will be hot, dry and flushed. Breath sounds may be decreased
over the affected area with rales and possibly a pleural rub.
If consolidation occurs, there will be dullness or flatness
to percussion, bronchial breath sounds egophany and whispering
pectoriloquy. Depending on the degree of inflammation, chest
expansion may be decreased.
Pneumonia can usually be visualized on the chest x-ray as
an abnormality. With the chest x-ray, it can be determined
whether the pneumonia involves the alveolar areas, the interstitium,
if it is lobar, segmental or bronchopneumonia. If consolidation
occurs, the chest x-ray will show opacification.
white blood cell count will be elevated in the patient with
an active bacterial pneumonia, ranging from 15,000 to 30,000
per cubic millimeter (microliter). The patient may exhibit
moderate to severe hypoxemia and possible hypercarbia in the
presence of an underlying lung disease.
sputum specimen must be obtained to determine the causative
organism. It is paramount that the sputum specimen obtained
is from the lower bronchial tree. If a good specimen cannot
be expectorated, a transtracheal aspiration will usually provide
a sputum specimen. Once the specimen is obtained, the causative
organism can be identified and appropriate antibiotic treatment
therapy can be used to control a bacterial pneumonic process
and destroy the causative organism. However, some of the symptoms
of pneumonia must be treated to aid in the effective removal
of the exudate. If the patient is hypoxemic, this should be
treated with supplemental oxygen. Pleuritic pain should be
treated with analgesics to the extent that cough and ventilatory
drive are not suppressed. Dehydration should be prevented
and/or treated with fluid replacement. The patient with bacterial
pneumonia requires aggressive respiratory care to promote
hydration and expectoration of retained secretions.
typical pneumonia includes mycoplasmal pneumonia, adenovirus
pneumonia and psittacosis. These types of pneumonia differ
from bacterial pneumonia in that the onset is not as acute.
pneumonia is common in younger people and may be epidemic
in schools and the community. Symptoms usually begin with
a sore throat and cough and soon the patient presents with
headache, general malaise, fever, shivering and lymphadenopathy.
The cough is dry and productive of small amounts of viscid
mucus. Dyspnea and chest pain are rare. The chest examination
is commonly negative. Chest x-ray shows a unilateral lower
and disease courses for mycoplasma, adenovirus and psittacosis
pneumonia are quite similar. Adenovirus pneumonia can be fatal
in small children and infants. However, adenovirus pneumonia
is usually benign in the child and adult.
is acquired by inhalation of droplets from bird droppings,
particularly sick birds in the parrot family. It differs from
the other non-bacterial pneumonias in that symptoms may be
more severe and prolonged.
of infectious fungal organisms can cause an illness termed
as mycoses that results from direct tissue invasion by the
organism. These infections are usually not spread from individual
to individual; however, the organism will spread within the
lung. These diseases commonly appear in the patient with a
chronic debilitating disease.
of the mycoses consists of sputum specimen collections and
analysis. Treatment involves administration of the appropriate
of the more common diseases caused by fungal infection are
discussed below. Histoplasmosis is caused by a fungus commonly
found in chicken, bat, pigeon and starling droppings. It is
found predominantly in river valleys and in the United States,
it is prevalent in the Mississippi River Valley.
presents as an influenza-type bronchopneumonia. The chest
x-ray is similar to that seen in tuberculosis with calcification,
fibrosis and cavitations. Treatment involves the administration
of Amphotericin B.
is caused by inhalation of a fungal agent found in the soil.
It is prevalent in the arid areas of Utah, California, New
Mexico, Arizona and Texas. It is also know as San Joaquin
fever, desert rheumatism, valley fever and the bumps.
The symptoms of coccidiomycosis are similar to those of atypical
pneumonia. Diagnosis can often be made with the coccidioidin
skin test. Treatment involves the administration of Amphotericin
is also caused by a fungal agent found in the soil. The agent
is inhaled and, if disseminated, can affect not only the lungs,
but the skin, bones, sinuses and genitourinary tract. Diagnosis
can be confirmed with sputum culture and/or tissue biopsy.
Treatment involves Amphotericin B and 2-hydroxystilbamidine.
also known as farmers lung, is caused by inhalation
of an airborne fungus often found in hay or compost piles.
Infection can cause an asthmatic-type illness or development
of VC, cysts and necrosis.
of the asthmatic-type of aspergillosis (allergic bronchial
aspergillosis) involves sputum culture and skin testing. Cavitating
aspergillosis (aspergilloma) can be diagnosed with sputum
culture, chest x-ray and tomography. Aspergillosis may resolve
spontaneously or be treated with Natamycin or Amphotericin
is caused by a fungus found in pigeon and bird droppings.
Infection is associated with pleural effusion, lung cavitation
and calcification. Treatment involves Amphotericin B, although
cryptococcosis often is fatal due to its predilection for
the brain and its meninges.
tuberculosis is an infection by Mycobacterium tuberculosis.
Once the host is infected, the living organism remains in
the lung for years. Depending on the immunologic status of
the host, the tuberculosis will exist in an active, contagious
state or an inactive, dormant state.
incidence of tuberculosis has declined sharply since the advent
of appropriate chemotherapy and improved hygiene. Tuberculosis
is a worldwide disease and affects all people regardless of
age, sex or race. There has been an increase recently in new
cases of pulmonary tuberculosis in the United States. This
is thought to be due, in part, to the Asian refugees who are
arriving in the United States after an exposure period to
over-crowded, poorly ventilated quarters and subsequent poor
tuberculosis is an obligate, aerobic, gram-positive rod and,
therefore, finds the lung to be an ideal, dark, moist and
tuberculosis is carried as an airborne droplet which is transmitted
from the tuberculosis patient as he coughs, talks and breathes.
The particle is inhaled, travels to the alveoli and is deposited
in the lower lung fields. The bacilli develop slowly over
a period and infiltrate into the lymph and blood, thereby
spreading to other organs.
the lung, a lesion appears that contains the bacilli, surrounded
by necrotic tissue and leukocytes. This is known as a caseated
lesion. A fibrous tissue forms around the tubercle lesion;
if long standing, the tubercle becomes calcified. Once the
tubercle has encased the bacilli, the infection usually will
not spread, but will remain in the lower lung field. This
type of tubercle is called a primary focus.
the patient is reinfected (usually by breakdown of a primary
focus), the new lesion will usually occur in an apical segment
of the lung. Frequently, more than one lesion will appear
and the disease again can spread throughout the body.
is difficult to diagnose clinically due to its insidious onset.
It should always be suspected in the elderly, chronically-ill
patient with unexplained febrile episodes.
include weight loss, persistent cough, hemoptysis, chest pain,
malaise, anorexia and dyspnea. Physical examination of the
chest reveals tracheal deviation to the affected side, post-tussive
rales at the apices and signs of pleural effusion consolidation
chest x-ray may show an area of calcification within a shadow
accompanied by fibrosis. This area is usually found in the
apices. Cavitation is commonly seen. In miliary tuberculosis,
widespread bilateral miliary shadowing is seen. If soft shadows
do not appear in a series of chest x-rays, tuberculosis should
diagnosis of pulmonary tuberculosis can be made by a histologic
biopsy of a tubercle, pleural effusion, liver or bone marrow.
The patient with tuberculosis is moderately anemic with a
normal or low white blood cell count. Commonly, a polymorphonuclear
leukocytosis will appear.
A tuberculin skin test can indicate exposure to tuberculosis.
A negative test usually will determine the absence of tuberculosis.
A positive test indicates the need for further testing, including
x-rays and sputum samples.
of tuberculosis involves extensive chemotherapy regimens including
the use of Isoniazid (INH), Streptomycin, Ethambutol, Rifampin
or Pyrazinamide. Treatment should continue for at least 12
to 18 months; two years of therapy may be necessary in the
5. Pulmonary Embolic Disease:
circulation slows, venous blood tends to pool and thrombosis
may occur. A thrombus is defined as a blood clot. When a blood
clot dislodges and travels through the bloodstream, it is
termed an embolus. When an embolus travels to the pulmonary
circulation and lodges there, it is termed a pulmonary embolism.
embolism is a common occurrence in the hospital patient who
spends much of this time lying inactive. The most common source
of venous thrombosis is the lower leg and calf area.
clinical signs of pulmonary embolism depend upon the size
of the embolus. It can be small, medium-sized or massive.
A small embolus may pass unrecognized; whereas, a massive
embolus can cause shock, pallor, unconsciousness, centralized
chest pain, hypotension, neck vein distention, acute dyspnea
and tachycardia. An EKG will indicate right ventricular strain.
Thirty percent of the cases involving massive pulmonary emboli
of pulmonary embolism involves support of the cardiopulmonary
system with supplemental oxygen therapy, treatment of hypoxemia
and use of anticoagulant therapy to prevent further embolization.
6. Pulmonary Pathology Due to Trauma:
trauma or injury can result in damage to the lung tissue itself,
the pleura and/or chest wall. Forms of trauma that will be
discussed here are burns/smoke inhalation, penetrating chest
wounds, flail chest/rib fractures, gastric aspiration, near-drowning
principle cause of death from burn injury is due to respiratory
failure. This can be directly attributed to inhalation of
toxic smoke and fumes accompanied by pulmonary injury to the
upper airway. Carbon monoxide inhalation causes death in a
number of burn victims. Burn victims rarely present with carboxyhemoglobin
levels over 15%, as death will usually occur before this level
burn victim will commonly present with pulmonary edema in
the first 24 hours following initial injury. A diffuse bronchitis
can occur. The pulmonary complications of burns/smoke inhalation
can be divided into three categories; early, intermediate
complications are associated with inhalation of steam,
flames and toxic fumes. Damage occurs in both the upper and
lower tracheobronchial tree and is thought to be caused primarily
by the toxic substances rather than the heat. Inhalation of
steam and high temperature gas can cause edema and lead to
upper airway obstruction. Inhalation of toxic substances can
cause acute tracheobronchitis, airway edema and interstitial
complications can develop anywhere between 24 and 72 hours
following the initial injury. These include atelectasis caused
by mucosal sloughing and pulmonary hemorrhage. A productive
cough will reveal flecks of carbon in the sputum.
complications of burns/smoke inhalation include pneumonia,
sepsis, pulmonary embolism and ARDS.
function studies will show a decreased TLC, increased airway
resistance and increased work of breathing. Arterial blood
gases initially reveal hypoxemia, hypercapnia and respiratory
acidosis. Later, a metabolic acidosis will cause respiratory
cessation and hyperventilation.
fluid loss due to the burns will cause low cardiac output,
increased oxygen consumption and tachycardia. Bronchospasm
may be caused by the pulmonary injury and auscultation will
reveal wheezing. If pulmonary edema is present, rales will
be heard. The chest x-ray on admission may be normal, but
within 12 to 24 hours abnormalities will appear if lung damage
has occurred. Treatment of burns/smoke inhalation injury involves
cardiopulmonary support and prevention of pulmonary complications.
This may involve an artificial airway, mechanical ventilation
oxygen therapy, PEEP, bronchodilation, massive fluid replacement,
antibiotic therapy or steroid therapy depending upon the degree
of pulmonary complications.
penetrating injury to the chest wall can cause a tension pneumothorax.
As discussed earlier in this module, this is a life-threatening
injury and must be treated immediately by insertion of a chest
chest is a condition caused by fracture of the ribs or sternum
in two or more places. The result is paradoxical respirations
or a flailing of the chest. Upon normal inspiration, the chest
wall moves outward and then inward on expiration. With flail
chest, the unstable chest wall will be pulled in on inspiration
and pushed out with expiration. If the rib fractures are limited
to one side of the chest, the movements of the right and left
sides will be paradoxical to each other.
chest can rapidly lead to respiratory insufficiency if not
treated immediately. Treatment consists of endotracheal intubation
and mechanical ventilation in order to stabilize the chest
wall. Frequently, PEEP is required to maintain oxygenation.
Mechanical ventilation is continued until the chest wall is
sufficiently healed to facilitate spontaneous ventilation.
fractures can also cause a penetrating injury to the chest
and a subsequent tension pneumothorax. Again, this must be
immediately treated with the insertion of a chest tube.
of gastric contents into the tracheobronchial tree can cause
severe upper respiratory burns and subsequent inflammatory
processes. Gastric aspiration can lead to respiratory failure
and serious pulmonary complications. Treatment involves vigorous
suctioning and saline lavage. The cardiopulmonary system must
be supported as adverse symptoms occur. The major treatment
of gastric aspiration is prevention with placement of a nasogastric
tube for suction in the debilitated patient.
near-drowning is a form of aspiration; however, 10% of deaths
due to drowning are caused by laryngospasm and asphyxiation.
In seawater drownings, a large amount of fluid will be found
in the lungs on autopsy. In a freshwater drowning, there
will be minimal volumes of water found in the lung due to
absorption of the hypotonic solution.
the body temperature accidentally drops below 35°C, there
is a 50% mortality rate. Hypothermia can occur as a result
of exposure, Addisons disease, hypoglycemia, pituitary
insufficiency, myxedema, stroke, myocardial infarction, near-drowning,
pancreatitis and cirrhosis. Hypothermia is more apt to occur
in the neonatal or bed-ridden patient.
effects of hypothermia include bradycardia, decreased cardiac
output, decreased oxygen consumption, atelectasis, hypoventilation,
increased blood viscosity and increased chance of thrombosis.
major complications due to hypothermia relate not to the cooling
process, but rather to the warming process in the treatment
of hypothermia. If rapid warming processes are instituted,
oxygen consumption will increase rapidly. Cardiac output will
not increase as rapidly and circulatory failure may result.
In the presence of pre-existing heart disease, this stress
may cause the ventricles to fibrillate and death may result.
An increase in carbon dioxide production and VD/VT may result
with rewarming of the hypothermic patient. Arterial blood
gases (temperature corrected) must be monitored closely and
ventilation and oxygenation must be supported.
the patient is rewarmed, he may again become comatose due
to an increase in the cerebrospinal fluid pressure. This may
be accompanied by pulmonary edema. Lumbar puncture and removal
of a small amount of CSF will reduce the pressure and relieve
rewarming process should involve insulation of the body to
prevent further heat loss and core rewarming.
Rewarming by external means has proven to be dangerous, especially
to the patient with heart disease. Core rewarming
can be accomplished with a heart-lung machine and cardiopulmonary
bypass. Blood is taken from the femoral vein, heparinized,
warmed and returned to the aorta. At 34°C, the heart is
defibrillated and the heart-lung machine is disconnected.
Gee and Hodgkin, Respiratory Care - A Guide to Clinical Practice.
Philadelphia: J.B. Lippincott Company.
Essentials of Respiratory Diseases. Great Britain: C. Tingling
and Company, Ltd.
The Lungs in Health and Disease. Philadelphia: J.B. Lippincott
Burgess, Feeley and Miller, Applied Physiology of Respiratory
Care. Boston: Little, Brown and Company.
and Petty, Synopsis of Clinical Pulmonary Disease. St. Louis:
C.V. Mosby Company.
Pulmonary Pathophysiology. Baltimore: The Williams and Wilkins
VI. CLINICAL PROCEDURES
to the specific content of this module, no clinical procedures
are presented. The student is encouraged to read and review
all current literature dealing with changes and development
in the field of respiratory pathology.
No. 1 Asthma in a 28-Year-Old Female:
28-year-old female is admitted to the emergency room with
severe dyspnea and bronchospasm. Her husband has recently
been painting the upstairs bedroom using oil based enamel.
She is a known asthmatic and uses albuterol metered dose inhaler
at home as necessary to relieve bronchospasm. She is also
being maintained on a low dose of Prednisone. She has had
to use her inhaler every one to two hours during the night,
the previous day and this morning. The treatment gave her
minimal relief from bronchospasm.
she presents as a thin, white female in acute respiratory
distress. Breathing is labored and shallow. Respirations are
28 per minute. Breath sounds are decreased to absent with
a faint end-expiratory wheeze over the posterior basal lung
fields. The expiratory phase is prolonged. There is hyper-resonance
to percussion. The patient is tachycardic, flushed and diaphoretic.
is immediately placed on oxygen via nasal cannula at 5 lpm
after an Oxygen Saturation of 88% on room air was measured
via pulse oximetry. Respiratory therapy is called to administer
2.5 mg albuterol via a nebulizer. This therapy is repeated
every 30 minutes for three treatments. She is begun on an
intravenous aminophylline drip and her Prednisone dose is
patient is admitted to the medical ward and the intense bronchodilator
regimen is continued. She is given Albuterol treatments every
four hours via nebulizer for the first 24 hours and then switched
to metered dose inhaler. The aminophylline is discontinued.
week later, she is discharged from the hospital with instructions
to gradually taper the Prednisone dose with physicians
instruction and use Albuterol inhaler PRN for relief of bronchospasm.
She is encouraged to avoid any inhaled irritants.
No. 2 Pneumonia in a 38-Year-Old Male:
38-year-old male is admitted to the emergency room with fever,
chills, general malaise and a left-sided pleuritic pain. He
has recently suffered a bout of viral influenza and just recently
returned to work after a seven-day sick leave.
examination reveals a moderately obese, white male in mild
respiratory distress. Skin is hot and dry. Temperature is
101.8°F. The patient is tachycardic and tachypneic with
a pulse of 120 and a respiratory rate of 24 per minute. Breath
sounds are unequal to auscultation with expiratory wheezes
throughout the left, but there is a marked decrease in aeration
in the left base. There is an accompanying dullness to percussion.
on 4 lpm are:
pH = 7.45
PaC02 = 35 torr
Pa02 = 67 torr
HC03 = 24 mEq/L
chest x-ray is taken and a left lower lobe pneumonia is diagnosed.
A sputum specimen is obtained and cultured. The culture results
are positive for Streptococcus pneumoniae. The patient is
started on appropriate antibiotic therapy. Respiratory therapy
is called to evaluate the patient and begin appropriate therapy.
patient is started on nebulizer treatments with 2.5mg albuterol
adding 400mg mucomyst with every other treatment, appropriate
hydration and continued antibiotic therapy. The patient begins
to expectorate thick, mucopurulent, green sputum and rales
are heard over the left base of the lung.
is continued and, after one week, the chest x-ray shows a
marked improvement in the pneumonic process. The patient is
a 7 day stay in the hospital, the patient is discharged home.
No. 3 ARDS following Viral Pneumonitis in a 28- Year-Old Male
28- year-old, previously healthy man was admitted to the hospital
complaining of high fever and total body aching. Upon examination
he was found to have a fever of 102.3, respiratory rate of
32, with elevated WBC of 28,000, HR of 143, and BP of 140/100.
On his third hospital day he became increasingly dyspneic,
tachypneic, and revealed a refractory hypoxemia to 100% oxygen.
His chest x-ray interpretation changed from resolving
interstitial pneumonitis to a typical ARDS pattern.
Upon transfer to the intensive care unit he was noted to be
very short of breath, using all accessory muscles, and unable
to speak more than three words at a time. Arterial Blood Gas
PaCO2 = 29
Pa O2 = 41
a careful explanation of the proposed therapy, the patients
nose was appropriately anesthetized and he was intubated by
the nasotracheal route. He was placed on a CPAP system with
5 cm H2O CPAP and 60% inspired oxygen; 15 minutes following
intubation ABGs were:
PaCO2 = 31
PaO2 = 45
was increased to 10 cm H2O; 5 minutes later:
PCO2 = 30
PaO2 = 43
was increased to 15 H2O: 10 minutes later;
PaCO2 = 32
PaO2 = 58
patient was observed for another 10 minutes, during which
vital signs, clinical condition, and blood gases remained
unchanged. CPAP was then increased to 20 cm H2O. Ten minutes
PaCO2 = 35
PaO2 = 110
patients breathing was significantly less labored, and
he communicated that he felt very much improved; 15 minutes
later on 20 cm H2O CPAP:
PaCO2 = 38
PaO2 = 180
FIO2 was decreased to .50; 10 minutes later vital signs were
unchanged and ABGs were:
PaO2 = 110
FIO2 was decreased to .40. 20 minutes later vital signs were
unchanged with ABGs:
PaCO2 = 37
PaO2 = 73
should be noted that at this time with proper levels CPAP
adjusted at 10 to 15 minute intervals the patients PaO2 was
corrected without the intervention of mechanical ventilation.
With initiation of CPAP therapy the clinical goals were reached,
Circulatory and perfusion status remained adequate and stable.
2. Adequate arterial oxygenation at FIO2 of .40
3. Work of breathing was significantly diminished; the patient
patient remained on CPAP therapy for an additional 48 hours
and was successfully placed on 21/m Nasal Cannula.
No. 4 Chronic Bronchitis ( Blue Bloater) in a 56-Year Old
56- Year-old male is admitted to the emergency room extremely
short of breath, with fever, chills and a non-productive cough.
He reports a hospitalization for pneumonia last month and
returned to work this past week, but complains of lethargy
and difficulty in focusing and concentrating. He has a 38-
year history of smoking a pack a day. He has tried to quit
on several occasions but has been unsuccessful. He also has
a history of high blood pressure, congestive heart failure
and Type II diabetes. The patient states that he has had a
chronic cough but has difficulty in raising secretions. He
has to use his inhaler every one to two hours during the night.
The M.D.I. contains albuterol and it gives him minimal relief.
he presents as an obese, Caucasian male in moderately severe
distress. His breathing is labored, rapid, and shallow. His
respirations are 28 breaths per minute. Breath sounds are
decreased to absent with a faint end-expiratory wheeze over
the posterior basal lung fields. The expiratory phase is prolonged.
There is a hyperresonance to percussion. Tactile fremitus
is present over both fields. The patient is tachycardic, and
at times flushed and diaphoretic.
37 ° C (98.6 °F)
= 32/ min
examination reveals a moderately obese patient with a barrel
chest. He has clubbing of his fingers. He is cyanotic and
2+ pitting edema of his ankles. Respirations are labored and
he is pursed lip breathing. He is using his accessory muscles
of respirations and appears tired and weak. He also appears
dehydrated. The patients skin is hot and moist. Breath
sounds are unequal to auscultation with expiratory wheezes
throughout both lung fields. He has a weak cough with small
amounts of a thick tenacious yellow secretion. A Chest X-ray
and an EKG were obtained and a venous blood sample was collected
for Hematology and Chemistry analysis.
blood gasses were drawn on room air and the results reveal:
HCO3= 32 mEq./L.
PaO2 = 42
patient is admitted to the hospital and he is immediately
placed on oxygen via a nasal cannula at 2 lpm. An I.V. is
started to rehydrate the patient and a catheter was inserted
to monitor his intake and output. The patient was placed on
the appropriate cardiac and pulmonary medications as well
as a diuretic and potassium replacement.
later, prior to discharge, Pulmonary Function studies were
performed. Spirometry revealed an FEV of 75% of predicted.
The patient was discharged from the hospital on 1.5 L./min.
of oxygen via a nasal cannula with instructions for referral
to enroll in a Pulmonary Rehabilitation Program. Prior to
discharge, the patients arterial blood gas values were:
HCO3 = 35
PaO2 = 65
No. 5 Bronchlectasis in a 25- Year Old Female:
25-Year-old female is admitted to the emergency room with
fever, chills, general malaise and a chronic cough. She has
a continuous productive cough of large amounts of foul-smelling,
purulent sputum. She also has some hemoptysis.
complains of constant and severe shortness of breath and appears
cyanotic. She is pursed-lip breathing and uses her accessory
muscles to breathe. During each coughing episode, she expectorates
large amounts of foul-smelling, yellowish-green sputum.
she presents as a well-nourished Hispanic female in moderate
distress. Her breathing is labored at times with a frequent
forceful cough. Respirations are 28 per minute. Breath sounds
reveal both sonorous rales and rhonchi. The expiratory phase
is prolonged. There is a hyperresonance to percussion. The
patient is tachycardic, flushed and diaphoretic. She reports
a productive cough whenever she changes positions, especially
when she is lying in bed. When she collects her sputum in
a container, it separates into three distinctive layers.
= 37.9° C (100.2° F)
examination reveals a moderately obese, female in mild respiratory
distress. The patients skin is warm and dry. Breath
sounds are equal to auscultation with expiratory wheezes throughout.
She appears somewhat cyanotic with some digital clubbing.
white count was elevated and a sputum sample was obtained
for a culture and sensitivity. Arterial blood gases were drawn
on 2 L/min. of oxygen and the results reveal:
PaCO2 + 54
HCO3 = 32m
chest X-rays revealed a generalized cystic bronchiectasis,
alveolar hyperinflation, and increased bronchovascular markings.
The current chest film revealed opacity in the left lower
lobe that is consistent with atelectasis or an acute pneumonic
was placed on oxygen via a nasal cannula at 3 lpm, given fluids
orally and started on a gram-negative antibiotic.
several days, the patient began to feel better. Pulmonary
Function studies were performed. Spirometry revealed a marked
improvement in both her static lung volume and her flowrates.
Her FEV1 increased to 73%.
sputum culture revealed Pseudomonas aeruginosa and some colonies
of Streptococcus pneumoniae. Her antibiotic regimen was modified
accordingly. She was placed in a Secretion Management Protocol,
which was used in conjunction with positive expiratory pressure
(P.E.P.), and the Percussionaire. This was maintained for
several days until the amount of sputum produced was less
than 5 ml. per therapy.
patient was discharged with instructions on how to perform
effective autogenic bronchopulmonary drainage. The patient
was also instructed on the use of a mechanical mucus clearance
device (Flutter Valve).
No. 6 Cystic fibrosis in an 18-Year-Old Male:
18- year old Caucasian male is admitted to the emergency
room with fever, chills general malaise and a chronic productive
cough. He has a continuous productive cough of large amounts
of sweet-smelling, purulent sputum. He also has some hemoptysis.
patient complains of constant and severe shortness of breath
and appears cyanotic. He utilizes his accessory muscles of
respiration. In addition he is pursed-lip breathing and appears
agitated. During each coughing episode, he expectorates large
amounts of sweet- smelling, thick, tenacious yellow-green
sputum. Clinically, he presents as a pale, thin emaciated
white male in moderate distress. He has a barrel chest and
his breathing is labored at times with a frequent, forceful
cough. Respirations are 28 per minute. Breath sounds are decreased
to absent with faint end-expiratory wheezes over the posterior
basal lung fields. Crackles and rhonchi are heard throughout
both lung fields. His expiration phase is prolonged. There
is a hyperresonance to percussion. The patient is tachycardic,
flushed and diaphoretic. He also has a huge appetite and fatty,
= 38.9° C (101.2 °F)
= 116 bpm
examination reveals a thin, pale white male in mild respiratory
distress. The patients skin is warm and dry. Breath
sounds are equal with inspiratory and expiratory wheezes throughout.
There is an accompanying hyperresonance to percussion. His
neck veins are distended and he shows mild to moderate peripheral
edema. He states that his shortness of breath has been getting
blood gasses were drawn and the results reveal:
pHa = 7.52
PaCO2 = 58mm.
HCO3 = 43
PaO2 = 62
is placed on oxygen via a nasal cannula at 4 lpm. The patient
is admitted to the hospital for a tune-up. Venous
blood was obtained for Hematology and Chemistry. Sputum was
obtained for culture and sensitivity. Patient was also started
on a pulmonary toilet regimen.
sputum culture revealed Pseudomonas aeruginosa and some colonies
of Streptococcus pneumoniae. His antibiotic regimen was modified
accordingly. He was placed in a Secretion Management Protocol,
which was used in conjunction with positive expiratory pressure
(P.E.P.), and the Percussionaire. This was maintained for
several days until the amount of sputum produced was less
than 5 ml. per therapy.
One week later the patient was discharged.
No. 7 Pickwickian Syndrome in a 25-Year-Old Female:
25-year-old, 5 foot, 350 pound female is admitted to the emergency
room in an obtunded state. She complains of a constant headache,
lethargy and the inability to focus, concentrate or stay awake.
Clinically, she presents as an obese white female in severe
= 37° C (98.6 °F)
= 130 bpm
examination reveals a morbidly obese, white female in respiratory
failure. The patients skin is cool and dry. Breath sounds
are decreased, but equal to auscultation.
Arterial blood gasses are drawn on room air and the results
pHa = 7.20
PaCO2 = 86
HCO3 = 18
PaO2 = 46
Alveolar-arterial (PaO2-PaO2) gradient is normal. The patient
is intubated, committed to mechanical ventilation and transferred
to the Medical Intensive Care Unit. The patient is placed
on a vigorous weight reduction program and a Gastro-Intestinal
consult is requested.
days later the patient was weaned from the ventilator. In
preparation for extubation, the procedure was explained to
the patient. The patient was then hyperoxygenated with 100%
oxygen for several minutes. Secretions were aspirated from
the trachea and then from the oro and nasopharynx. The cuff
was deflated and the tube removed at the point of end inspiration.
Then the patient was coached to cough as deeply as possible
to clear secretions.
Just prior to discharge, the patients arterial blood
gas values were:
pHa = 7.40
PaCO2 = 40mm.
HCO3 = 24
PaO2 = 92
patient was discharged on a nutrition-exercise program and
referred to a behavior modification support group.
No. 8 Pneumonia (Bacterial) in a 25-Year-Old Male:
25-year-old Caucasian male schoolteacher is admitted to the
emergency room with mild fever, chills, general malaise and
a hacking, non-productive cough. He complains of constant
lethargy and flu-like symptoms for the past five
days, and he is getting progressively worse. He is very short
of breath and his cough is becoming more frequent.
he presents as a tall, thin, white male in moderate respiratory
distress. His breathing appears labored at times with a frequent,
forceful cough. Respirations are 28 per minute. Breath sounds
are decreased to absent with a faint end-expiratory wheezes
over the posterior basal lung fields. The patient states that
he is very short of breath. He has a frequent, strong,hacking
sometime productive cough. The patient coughs up a small amount
of yellow-brown, blood-streaked sputum.
= 38.3 °C (101.2° F)
= 126 bpm
examination reveals a well developed, well nourished white
male in mild respiratory distress. His skin is pale and damp.
Breath sounds are unequal to auscultation with bronchial breath
sounds over the right lower lung regions posteriorly. There
are also faint expiratory wheezes throughout the right lower
lung. There is an accompanying dullness to percussion posteriorly
over the right lower same.
venous blood sample is obtained for a C.B.C. and a sputum
specimen for culture and sensitivity. Both are sent to the
Arterial blood gases are drawn and the results reveal:
pHa = 7.56
PaCO2 = 24
HCO3 = 20
PaO2 = 58
patients chest film reveals right lower lobe infiltrates,
air bronchograms, and alveolar consolidation. His W.B.C. is
23,500. The patient is hydrated, placed on oxygen via a nasal
cannula at 5 lpm and started on the appropriate antibiotic
therapy. The next morning, the chest X-ray indicates partial
resolution of the pneumonic process but a persistent atelectasis
or consolidation in the right lower and middle lobes. The
tactile and vocal fremitus has increased. Dull percussion
notes and bronchial breath sounds are still heard. The patient
is hospitalized for an additional day.
the next day, the arterial blood gases are drawn on room air
and the results reveal:
pHa = 7.44
PaCO2 = 36mm.
HCO3 = 22
PaO2 = 58
patient is discharged to home to resume his normal daily activities.
no. 9 Spontaneous Pneumothorax in a 16 Year-Old Male:
16 year-old white male is admitted to the emergency room with
severe dyspnea and in obvious respiratory distress. The patient
was jogging around the track of a local college when he suddenly
became short of breath. The patient states that one minute
he was breathing fine and the next minute he suddenly became
short of breath.
the patient presents as a thin, well-developed, well nourished
white male in moderate distress. His breathing is labored
with a frequent, forceful cough. Respirations are 22 per minute.
Breath sounds are decreased to absent on both sides with a
faint end-expiratory wheeze over the posterior basal lung
fields. The expiratory phase is prolonged. There is a hyperresonance
to percussion bilaterally. The patient is tachycardic, flushed
and slightly diaphoretic.
= 37.9° C (100.2 °F)
examination reveals a thin white male in mild respiratory
distress. The patients skin is warm and dry. Breath
sound are unequal to auscultion with expiratory wheezes throughout
the left. There is an accompanying dullness to percussion
on the left side. The trachea is shifted to the right side.
blood gasses were drawn on room air and the results revealed:
HCO3 = 36
PaO2 = 58
X-ray revealed a dark, translucent area ion the left lung
field confirming the presence of air in the intrapleural space
on the left side. The patient was immediately placed on oxygen
via a nasal cannula at 6 lpm to assist in the reduction of
the left-sided pneumothorax. After eight hours, a repeat X-ray
shows no substantial reduction in the pneumothrax, therefore,
a chest tube was inserted and connected to a pleuravac and
25-cm. of negative pressure. The patient was admitted to the
medical floor. On the following day, a follow-up chest film
showed the lung to be fully reexpanded.
patient was discharged to home.
No. 10 Pulmonary Embolic Disease in a 25-Year Old Female:
agitated 25-year-old Asian female truck driver is admitted
to the emergency room with extreme shortness of breath. She
complains of a constant and severe shortness of breath and
she appears both shockey and cyanotic. She has a productive
cough, of small quantity of blood-tinged sputum. She states
she has a feeling of impending doom. The patient went on to
state that she feels awful and has both chest pressure, chest
pain, and is light headed. She experiences marked dyspnea
with minimal exertion.
= 37.9*C (100.2*F)
= 125 bpm
examination is unremarkable. The patient denies smoking cigarettes,
but her fingers have tobacco stains. Her E.K.G. alternates
between normal sinus rhythm, sinus tachycardia, and atria
flutter. Echocardiography reveals right atrial and right ventricular
enlargement. The estimated pulmonary artery pressure is 55
blood gases were drawn and the results reveal:
PaCO2 = 28
PaO2 = 53mm.
patient is immediately placed on oxygen via a nasal cannula
at 51pm with instructions to keep the SaO2> 92%. A ventilation-perfusion
scan is ordered and I.V. streptokinase administered. The patient
is admitted to the Coronary unit and prepped for a P.T.E.
Pulmonary Function study demonstrated a rather significant
restrictive defect with a total lung capacity of 62% of predicted.
There is also a mild obstructive component with an FEV1/FVC
of 70%. The DLCO is 12.3 (38% of predicted).
ventilation/perfusion scan describes matched ventilation/perfusion
defects in each lung.
chest CT scan demonstrates apparent filling defects in both
proximal lower lobe pulmonary arteries. Also noted were apical
bullous emphysematous changes. The patient has significant
lung disease and a level of dyspnea, which seems disproportionate
to her pulmonary hypertension. A formal evaluation did confirm
the presence of a pulmonary thrombus. The patient underwent
a pulmonary thromboendarterectomy. Her recovery was uneventful.
week later, the patient was discharged from the hospital.
No. 11 Pulmonary Edema in a 72-Year-Old Male:
anxious 72-year-old black male presentes to the emergency
room in respiratory distress with a frequent cough. He was
producing small amounts of frothy pink secretions. His neck
veins and abdomen are distended, and there is 3+ pedal edema.
He complains of constant and severe shortness of breath and
he presents as a thin, emaciated black male in moderate distress.
He has a barrel chest and uses his accessory muscles of respiration.
His breathing is labored at times with a frequent, forceful
cough. Respirations are 28 per minute. Breath sounds are decreased
to absent with faint end-expiratory wheezes over the posterior
basal lung fields. The expiratory phase is prolonged. There
is a hyper-resonance to percussion. The patient is tachycardic,
flushed and diaphoretic.
= 37.9° C (100.2° F)
= 145 bpm
examination reveals a emaciated, black male in acute respiratory
distress. His skin is cool and moist. Breath sounds were decreased
and equal to ausculation with expiratory wheezes throughout.
There is an accompanying dullness to percussion.
blood gases are drawn on 4 lpm. And the results reveal:
PaCO2 = 28
HCO3 = 22
PaO2 = 61
oxygen via a nasal cannula is increased to 5 lpm. The chest
X-ray shows dense, fluffy opacities over the lower lung areas
bilaterally. It is also noted the presence of right ventricular
hypertrophy. The patient is stabilized in the emergency room
and then transferred to the cardiac Care Unit.
the patient was still hemodynamically unstable, a Swan-Ganz
multi-lumen flow- directed catheter was inserted and hemodynamic
measurements were obtained. His cardiac output was 2.5 L/min.,
which is reduced, as well as his cardiac index. His SVR was
650 and his PVR was 225. His wedge pressure (L.V.E.D.P.) was
reduced indicating Left Ventricular Congestive Heart Failure.
Blood Urea Nitrogen was elevated and the serum sodium was
reduced. Intake and Output reflect positive fluid balance.
patient was placed on the appropriate cardiogenic medications
to increase the mean arterial pressure and a diuretic to establish
the fluid compartments. He responded hemodynamically and began
patient was transferred out of the unit and enrolled in the
Cardiac Rehabilitation Program.
No 12 Pulmonary Tuberculosis in a 25-Year-Old Female:
25-year-old black female is admitted to the emergency room
reporting night sweats, chills, general malaise and a chronic
cough. A few days ago, she developed episodes of coughing
that were more severe than usual. On several occasions, the
coughing episodes lasted for up to an hour. During these episodes,
her sputum was sometimes blood-tinged (hemoptysis). Prior
to this admission, she coughed up frank bright-red
blood. She complains of constant and severe shortness of breath
and she has difficulty in catching her breath. During each
of these coughing episodes, she brings up large amounts of
blood with sometimes yellowish sputum.
she presents as a thin, almost emaciated black female in moderate
distress. She uses her accessory muscles for respiration.
Her breathing is labored at times with a frequent, forceful
cough. Respirations are 25 per minute. Breath sounds are decreased
to absent with faint end-expiratory wheezes over the posterior
basal lung fields. Although palpation of the chest is negative,
dull percussion notes and increased tactile and vocal fremitus
are noted over the lung bases. Bronchial breath sounds are
heard over the right and left lung bases. Crackles and rhonchi
are noted over the left upper lobe.
= 38.9° C (101.2°.F)
examination reveals a black female in respiratory distress.
The patients skin is warm and dry. The Chest X-ray reveals
an increase in opacities consistent with pneumonia in the
left lower lobe. The white count came back at 16,500.
blood gases are drawn and the results reveal:
PaCO2 = 50
HCO3 = 41
PaO2 = 50
is immediately placed on oxygen via a nasal cannula at 4 lpm.
P.P.D. (Mantoux) skin test is placed. A sputum specimen is
obtained and sent to the clinical laboratory for an A.F.B.
and the patient is started on antituberclin medications.
patient is started on Isoniazid, Ethambutol and Streptomycin,
but develops a skin rash after two days. The Ethambutol is
discontinued and replaced with Rifampin.
several days, the patient began to show improvement and her
oxygen was reduced to 2 lpm. A repeat Chest X-ray showed that
the parenchymal densities had improved. The sputum showed
patient was discharged two days later.
No. 13 Near Drowning in a 19-Year-Old Male:
agitated 19-year old white male near-drowning victim presents
to the emergency room in respiratory distress breathing spontaneously.
He and some of his friends were having a party aboard a pleasure
craft on Mission Bay. The young man was sitting on the railing
when something jarred the craft and the patient went overboard.
He was not breathing when he was pulled from the water. The
owner of the boat called the harbor police and the Coast Guard
and two friends began CPR When the harbor police arrived,
they continued C.P.R. The patient remained unconscious and
his pupils were fixed and dilated. He had no cardiac activity
and no spontaneous respirations. An esophageal obturator was
inserted and the patient was placed on 100 % oxygen while
C.P.R was continued. Within several minutes, the boat docked
at shore where an ambulance was waiting. The patient was transported
to Mission Bay Hospital. He was semiconscious, combative and
belligerent. His pupils were no longer fixed and dilated.
he presents as a well-nourished, white male in respiratory
distress. He has symetric chest excursion. His breathing is
labored at times with a frequent, forceful cough. Respirations
are 28 per minute. Breath sounds are decreased to absent with
faint fine crackles and end-expiratory wheezes over the posterior
basal lung fields. The expiratory phase is prolonged. The
patient is tachycardic.
= 32.3° C (90.3 °F)
examination reveals an obtunded patient in respiratory distress.
Arterial blood gasses were drawn on 100% and the results revealed:
PaCO2 = 75
HCO3 = 16
PaO2 = 54
patient was intubated, placed on a mechanical ventilator and
transferred to the Surgical Intensive Care Unit. After he
was sedated and stabilized, another arterial blood gas was
drawn and a portable chest film taken. The Chest X-ray showed
that the endotracheal tube was correctly positioned and bilaterally
patchy infiltrates were noted in both lower lobes. There were
also dense, fluffy opacities over the lower lung areas bilaterally.
The arterial blood gasses were drawn on an F1O2 of .50 and
the results reveal:
Pa CO2 = 51
HCO3 = 19
PaO2 = 54
Swan-Ganz catheter was placed. The patients condition
began to deteriorate. Dull percussion notes were now heard
throughout both lung fields, and more prominent crackles and
rhonchi were heard over both lungs. A moderate amount of frothy,
white sputum was being suctioned. The patients cardiopulmonary
status remained critical. Despite aggressive suctioning, crackles
and rhonchi were now abundant throughout all lung fields.
Frothy, pink secretions continued to be suctioned. A follow-up
Chest X-ray revealed fluffy infiltrates throughout both lung
fields and was consistent with a pulmonary edema pattern.
patient was discharged too.
pl. Acini [L, grape], 1. Any small sac-like structure, particularly
one found in a gland. 2. A subdivision of the lung consisting
of the tissue distal to a terminal bronchiole. Also called
[Gk, anti + genein, to produce], a substance, usually a protein,
that causes the formation of an antibody and reacts specifically
with that antibody.
[L, apices], referring to the upper lobe of one lung.
[L, auscultare, to listen], the act of listening for sounds
within the body to evaluate the condition of the heart, blood
vessels, lungs, pleura, intestines or other organs. Auscultation
may be performed directly, but most commonly a stethoscope
is used to determine the frequency, intensity, duration, and
quality of the sounds. During auscultation of the lungs the
patient usually sits upright and is instructed to breathe
slowly and deeply through the mouth. The anterior and posterior
surfaces of the thorax are auscultated from apex to base with
comparasons made between the right and left sides; when the
posterior chest is examined, the patient is asked to bring
the shoulders forward so that a greater surface of lung can
[L, bronchiolus, little windpipe], a small airway of the respiratory
system extending from the bronchi into the lobes of the lung.
There are two divisions of bronchioles: The terminal bronchioles
pass inspired air from the bronchi to the respiratory bronchioles
and expired waste gases from the respiratory bronchioles to
the bronchi. The respiratory bronchioles function similarly,
allowing the exchange of air and waste gases between the alveolar
ducts and the terminal bronchioles.
[L, calx + facere, to make], the accumulation of calcium salts
in tissues. Normally, about 99% of all the calcium entering
the human body is deposited in bones and teeth; the remaining
1% is dissolved in body fluids such as the blood. Disorders
affecting the delicate balance between calcium and other minerals,
parathyroid hormone, and vitamin D can result in calcium deposits
in arteries, kidneys, lung alveoli, and other tissues, interfering
with usual organ function.
[ L, caseus, cheese], a form of tissue necrosis in which there
is loss of cellular outline and the appearance is that of
crumbly cheese. It is typical of tuberculosis.
rale [L, caverna + Fr rattle], an abnormal hollow, metallic
sound heard during auscultation of the thorax. It is caused
by contraction and expansion of a pulmonary cavity during
respiration and indicates a pathologic condition.
[L, complere, to complete], 1. Fulfuillment by the patient
of the care-givers prescribed course of treatment. 2.
A measure of distensibility of the lung volume produced by
a unit pressure change.
[L, crackling], a sound that resembles the crackling noise
heard on an open fire. The rales of a consolidated area of
the lung in pneumonia. Also called crepitation.
[Scot, to croak], an acute viral infection of the upper and
lower respiratory tract that occurs pimarily in infants and
young children 3 months to 3 years of age after an upper respiratory
tract infection. It is characterized by hoarseness, fever,
a distinctive harsh, brassy cough, respiratory distress resulting
from obstruction of the larynx. The most common causative
agents are the parainfluenza viruses, especially type 1, followed
by the respiratory syncytial viruses (RSV) and influenza A
and B viruses.
pl. diagnoses [Gk, dia + gnosis, knowledge]. 1. Identification
of a disease or condition by a scientific evaluation of physical
signs, symptoms, history, laboratory test, and procedures.
Kinds of diagnoses are clinical diagnosis, differential diagnosis,
laboratory diagnosis, nursing diagnosis and physical diagnosis.
2. The art of naming a disease or condition.
[Gk, dys + pnoia, breathing], a shortness of breath of a difficulty
in breathing that may be caused by certain heart conditions,
strenuous exercise, anxiety or a verity of pulmonary conditions.
Effusion [L, effundere, to pour out], 1. The escape of fluid
from blood vessels because of rupture of seepage, usually
into a body cavity. The condition is usually associated with
a circulatory or renal disorder and is often an early sign
of congestive heart disease. The term may be associated with
a affected body area, as pleural or pericardial effusion
[Gk., atia, cause, logos, science], 1. The study of all factors
that may be involved in the development of a disease, including
susceptibility of the patient, the nature of the disease agent,
and the way in which the patients body is invaded by
the agent. 2. The cause of a disease.
[L, fibra, fiber], consisting mainly of fibers or fiber-containing
materials, such as fibrous connective tissue.
[ Gk, hypo + oxys, sharp, genein, to produce, hamia, blood],
an abnormal deficiency of oxygen in the arterial blood. Symptoms
of acute hypoxemia are cyanosis, restlessness, stupor, coma,
Cheyne- Stokes breathing, apnea, increased blood pressure,
tachycardia, and an initial increase in cardiac output that
later falls, resulting in hypotension and ventricular fibrillation
or asystole. Chronic hypoxemia stimulates red blood cell production
by the bone marrow, leading to secondary polycythemia. Hypoxemia
caused by decreased alveolar oxygen tension or underventilation
improves with oxygen therapy. Hypoxemia resulting from shunting
of blood from the right side of the heart to the left side
of the heart without exchange of gases in the lungs is treated
with bronchial hygiene and positive and expiratory pressure
[L, insidiousus, cunning], of, pertaining to, or describing
a development that is gradual, subtle, or imperceptible. Certain
chronic disease, such as glaucoma, can develop insidiously
with symptoms that are not detected by the patent until the
disorder is established.
[L, laesus, an injury], 1. A wound, injury or pathogenic change
in body tissue. 2. Any visible, local abnormality of the tissues
of the skin, such as a wound, sore, rash or boil. A lesion
may be described as benign, cancerous, gross, occult, or primary.
[Gk, leukos= kytos, cell, osis, condition], an abnormal increases
in the number of circulating white blood cells. An increase
often accompanies bacterial, but not usually viral, infections.
The normal range is 5000 to 10,000 white cells per cubic millimeter
of blood. Leukemia may be associated with a white blood cell
count as high as 500,000 to 1 million per cubic millimeter
of blood, the increase being either equally or disproportionately
distributed among all types. Kinds of leukosytosis include
basophilia, eosinophilia, and neutophilia.
[L, membrana, thin skin], a thin layer of tissue that covers
a surface, lines a cavity, or divides a space, such as the
abdominal membrane that lines the abdominal wall and Descernets
membrane between the subtantia propria and the endothelium
of the cornea. The principal kinds of membranes are mucous
membrane, serous membrane, synovial membrane, and cutaneous
[L, mucus + purulentus, puss], characteristic of combination
of mucus and pus.
[Gk, orthos + pnosis, breath], an abnormal condition in which
a person must sit or stand to breathe deeply or comfortably.
It occurs in many disorders of the cardiac and respiratory
systems, such as asthma, pulmonary edema, emphysema, pneumonia,
and agina pectoris.
[Gk, pan + lobos, all lobes], any condition involving all
areas of the lung.
breathing [Gk, paradoxos; AS, breath], a condition in
which a part of the lung deflates during inspiration and inflates
during expiration. The condition usually is associated with
a chest trauma, such as an open chest wound or rib cage damage.
In such cases, the paradoxical breathing that occurs spontaneously
is sometimes called internal paradoxical breathing. External
paradoxical breathing may be observed during deep general
[Gk, papa + enchyma, infusion], the tissue of an organ as
distinguished from supporting or connective tissue.
Pleura [Gk, rib], a delicate serous membrane enclosing the
lung, composed of a single layer of flattened mesothelial
cells resting on a delicate membrane of connective tissue.
Beneath the membrane is a stroma of collagenous tissue containing
yellow elastic fibers. The pleura divides into the visceral
pleura, which covers the lung, dipping into the fissures between
the lobes, and the parietal pleura, which lines the chest
wall, covers the diaphragm, and reflects over the structures
in the mediastinum. The parietal and visceral pleurae are
separated from each other by a small amount of fluid that
acts as a lubricant, as the lungs expand and contract during
[L, containing pus], producing or containing pus.
[ME, shunten], 1. To redirect the flow of a body fluid from
one cavity or vessel to another. 2. A tube or device implanted
in the body to redirect a body fluid from one cavity or vessel
[Gk, stereos + eidos, form], any of a large number of hormonal
substances with a similar basic chemical structure, produces
mainly in the adrenal cortex and gonads.
[Gk, thorax + stoma, mouth], an incision made into the chest
wall to provide an opening for the purpose of drainage.
[Gk, thorax + temnein, to cut], a surgical opening into the
[Fr, tissu, fabric], a collection of similar cells acting
together to perform a particular function.
[Gk, tripsis, rubbing], a proteolytic digestive enzyme produced
by the exocrine pancreas that catalyzes in the small intestine
the breakdown of dietary proteins to peptones, peptides, and
fremitus [L, tussis, cough + fremitus, murmuring], a vibratory
cough that can be felt by a hand over the chest of the patient.