the air completely. A rare form of emphysema is
an inherited deficiency of the enzyme alpha-1-
antitrypsin (AAT), which regulates the presence of
elastin in the tissues of the alveoli. AAT deficiency
results in reduced elastin, further limiting alveolar
function. Because of the intimate correspondence
between the capillary BLOODsupply and alveolar
oxygen content, blood supply shifts away from
damaged alveoli.
The ultimate damage of COPD, regardless of
whether the primary course of disease started as
bronchial or alveolar, is so profound that both
dimensions of damage eventually overtake the
LUNGS and the lungs lose the ability to recoil
(return to their normal shape and size), diminish-
ing the ability to exhale. Consequently, people
who have COPD can breathe in with relative ease
but struggle to move air back out of their lungs.
People who have moderate to advanced COPD
typically exhale through pursed lips, an effort to
more forcefully exhale. Even with this effort, the
person may be unable to blow out a match.
As the disease process progresses the less elastic
lungs expand within the thoracic cavity, pushing
the ribs out and the DIAPHRAGMdown to produce a
characteristic barrel chest deformity. However,
these structural changes further limit the ability of
the diaphragm and intercostal muscles to expand
the chest for inhalation, restricting the ability of
the lungs to draw in air. This generates a charac-
teristic posture adaptation in which the person
leans forward to use other muscles in the neck
and shoulders to assist with BREATHING. Ordinary
movements such as raising the arms (such as to
wash or brush the hair) consequently cause short-
ness of breath because such movements reduce
the involvement of these ancillary muscles. In its
later stages COPD affects both inhalation and
exhalation.
Symptoms and Diagnostic Path
The symptoms of COPD include
- progressive DYSPNEA(shortness of breath)
- wheezing (whistling sounds with exhalation)
- persistent, productive COUGH
- HEMOPTYSIS(bloody SPUTUM)
- edema (swelling due to fluid retention) in the
feet, ankles, and lower legs - CYANOSIS(bluish hue to the lips and SKINthat
signals inadequate oxygenation)
- edema (swelling due to fluid retention) in the
- physical signs characteristic of COPD (barrel
chest, purse-lip breathing, forward-leaning pos-
ture) when emphysema is dominant - current or previous cigarette smoking
The diagnostic path includes a complete pul-
monary workup to evaluate lung capacity and
function, which typically show significant reduc-
tions. Chest X-rays and COMPUTED TOMOGRAPHY(CT)
SCANshow the extent of damage to the lungs as
well as displacement of the thoracic structures.
The doctor typically does sputum cultures to iden-
tify or rule out INFECTION. Diagnostic blood tests
often show an elevated ERYTHROCYTE(red blood
cell) count particularly in people who have low
oxygen levels, indicative of the body’s attempt to
improve the oxygen-carrying ability of the blood.
Diagnostic efforts focus on ruling out other possi-
ble causes for symptoms as well as correlating
physical findings with history of smoking.CLASSIFICATION OF CHRONIC OBSTRUCTIVE
PULMONARY DISEASE (COPD)
Classification Severity Symptoms
stage 0 at risk smokes but has no COPD
symptomsstage 1 mild chronic COUGHstage 2 moderate chronic, productive cough
DYSPNEAwith exertionstage 3 severe chronic, productive cough
excessive SPUTUM
dyspnea at rest
right HEART FAILUREcommonTreatment Options and Outlook
The most important element of treatment is SMOK-
ING CESSATION. Although it is not possible to reverse
damage that has already occurred, treatment aims
to minimize further lung damage and improve
function of the remaining lung. Medications such
as bronchodilators relax and open the airways,200 The Pulmonary System