Definition
A.A chronic and progressive respiratory disease characterized by expiratory airflow limitation.
Incidence
A.Chronic obstructive pulmonary disease (COPD) is the third leading cause of death in the United States and fourth leading cause of death worldwide.
B.The incidence is much higher in smokers and ex-smokers compared to nonsmokers.
C.It is more prevalent in individuals greater than 40 years with the greatest prevalence in those greater than 65 years.
D.Traditionally, prevalence has been higher in men but recent literature suggests the occurrence may be rising in women, and women may be more susceptible to poorer outcomes.
Pathogenesis
A.The lungs are exposed to a stimulus (e.g., smoking, fumes) that causes inflammation of the airways. Neutrophils and various other immune cells are recruited to the airways leading to breakdown of elastin fibers and increasing oxidative stress.
B.Ultimately, there is destruction of alveolar walls, decreased repair of the alveoli, fibrosis, and bronchiolar wall thickening leading to narrowed airways, impaired gas exchange, and enlarged air spaces.
Predisposing Factors
A.Tobacco smoke: Leading environmental risk factor.
B.Individuals greater than 40 years.
C.Occupational exposures to lung irritants (e.g., dust, chemical agents, fumes).
D.Alpha-1 antitrypsin is a genetic condition leading to COPD that should be tested in a new diagnosis of COPD.
E.Airway hyperresponsiveness (e.g., asthma).
F.Allergies.
G.Recurrent respiratory infections.
Subjective Data
A.Common complaints/symptoms.
1.Dyspnea (see Figure 2.1): Chronic and progressive. This is a cardinal symptom.
FIGURE 2.3 Algorithm for the evaluation of cough.
ACE, angiotensin-converting enzyme; COPD, chronic obstructive pulmonary disease; GERD, gastroesophageal reflux disease; HEENT, head, ear, eyes, nose, and throat.
2.Cough (see Figure 2.3) with or without sputum production.
a.Not uncommon for individuals to produce small amounts of sputum.
b.Increasing sputum production, especially with change in color: May indicate bacterial infection.
3.Wheezing (see Figure 2.2) and/or chest tightness.
4.Severe COPD: Possible fatigue, weight loss, and anorexia.
B.Family and social history.
1.Inquire about environmental risk factors and family history.
2.Inquire about smoking because it can accelerate or exacerbate COPD symptoms.
C.Review of symptoms.
1.Evaluate for symptom onset, duration, severity, associated symptoms (e.g., increased wheezing or sputum), and aggravating and alleviating factors.
2.Inquire about early onset of COPD.
3.Assess for risk factors such as a history of allergies, asthma, or recurrent respiratory infections.
Physical Examination
A.The physical examination for COPD is rarely diagnostic. Physical signs of COPD may or may not be present, depending on the severity of disease. However, it is still important to assess for the respiratory and systemic symptoms that may be associated with COPD.
B.General examination.
1.Assess the respiratory rate. It may be normal or increased.
2.Assess the patient’s posture. Leaning forward with outstretched palms is associated with an attempt to relieve dyspnea.
3.Check breathing. In advanced disease or severe dyspnea, pursed-lip breathing is possible.
4.Inspect for clubbing.
5.In more severe disease, cyanosis, elevated jugular venous pressure, and peripheral edema may be present.
C.Respiratory examination.
1.Inspect the chest.
a.Check for an increased anteroposterior chest diameter due to hyperinflation of the lungs, giving a barrel chest shape.
b.Assess for use of accessory muscles (e.g., sternocleidomastoids, scalenes, intercostals).
2.Percuss the chest wall.
a.Observe for hyperresonance due to overinflation of the lungs.
3.Auscultate bilaterally.
a.Diminished breath sounds throughout.
b.Occasional expiratory wheezing.
c.Prolonged expiratory phase.
d.Coarse rhonchi throughout the respiratory phase, especially during times of increased sputum production.
Diagnostic Tests
A.Pulmonary function test: Spirometry.
1.Objective measurement of airflow limitation.
2.Ratio between the volume of air forcibly exhaled after maximal inspiration (forced vital capacity [FVC]) and the volume of air forcibly exhaled during the first second (forced expiratory volume [FEV1]). A ratio less than 0.7 after bronchodilator testing indicates obstruction.
3.Reduced FEV1 (reduction in expiratory flow rates).
4.Possibly reduced FVC, usually to a lesser extent than the FEV1.
B.Chest x-ray (see Figure 2.3).
1.Hyperinflation, as evidenced by a flattened diaphragm and increased retrosternal air space.
2.Hyperlucency of the lungs.
3.Rapid tapering of the vascular markings.
C.Arterial blood gas (ABG).
1.May reveal hypercapnia and/or hypoxemia.
a.Early or mild COPD: Typically normal.
b.Worsening as COPD progresses. Individuals with moderate to severe disease may have a chronic respiratory acidosis often with metabolic compensation as evidenced by increased serum bicarbonate.
2.Can provide clues to the acuteness and severity of COPD in those individuals with an exacerbation.
D.Pulse oximetry.
1.Used to assess arterial oxygen saturation. If the pulse oximetry is less than 92%, then an ABG is warranted.