Chronic Obstructive Pulmonary Disease (Emphysema+Chronic Bronchitis)

Chronic obstructive pulmonary disease (COPD) is an inflammatory respiratory disease usually caused by exposure to tobacco smoke. It is characterized by the presence of airflow limitation that is not fully reversible. The pathophysiology of COPD is related to enhanced inflammatory response to noxious particles and gases, chronic airway irritation, mucus production, and pulmonary scarring and changes in pulmonary vasculature.

Traditionally, COPD was described as encompassing emphysema, characterized by loss of lung elasticity and destruction of lung parenchyma with enlargement of air spaces. And chronic bronchitis, characterized by obstruction of small airways and productive cough >3 months for more than 2 successive years.

CAUSES

  • Tobacco exposure
  • Occupational exposure to pulmonary toxins (e.g., dust, noxious gases, vapors, fumes, cadmium, coal, silica). The industries with the highest exposure risk are plastics, leather, rubber, and textiles.
  • Atmospheric pollution.
  • Alpha-1-antitrypsin deficiency (rare; <1% of COPD patients).

PHYSICAL & CLINICAL FINDING

Patients with COPD have historically been classically subdivided in two major groups based on their phenotype

  1. Blue bloaters are patients with chronic bronchitis; the name is derived from the bluish tinge of the skin (as a result of chronic hypoxemia and hypercapnia) and from the frequent presence of peripheral edema (from cor pulmonale); chronic cough with production of large amounts of sputum is characteristic.
  2. Pink puffers are patients with emphysema; they have a cachectic appearance but pink skin color (adequate oxygen saturation); shortness of breath is manifested by pursed-lip breathing and use of accessory muscles of respiration.

COPD may present with combinations of the following signs and symptoms:

  1. Cyanosis, chronic cough (usually productive but may be intermittent and may be unproductive), tachypnea, tachycardia.
  2. Dyspnea (persistent, progressive), pursed-lip breathing with use of accessory muscles for respiration, decreased breath sounds, wheezing.
  3. Chronic sputum production.
  4. Chest wall abnormalities (hyperinflation, “barrel chest,” protruding abdomen).
  5. Flattening of diaphragm

DIFFERENTIAL DIAGNOSIS

  • Heart failure (HF)
  • Asthma
  • Tuberculosis, other respiratory infections
  • Bronchiectasis
  • Cystic fibrosis
  • Neoplasm
  • Pulmonary embolism
  • Obliterative bronchiolitis
  • Diffuse panbronchiolitis
  • Sleep apnea, obstructive
  • Hypothyroidism <50% predicted
  • Neuromuscular disease

DIAGNOSTIC WORKUP

  • Chest X-Ray
  • Spirometry pulmonary function testing
  • Oxygen saturation & ABG
  • Alpha-1-antitrypsin deficiency screening
  • CBC
  • Sputum culture

TREATMENT

  • Avoidance of tobacco and elimination of air pollutants.
  • Supplemental oxygen, usually through a face mask/nasal cannula, to ensure oxygen saturation >90% as measured by pulse oximetry. Continuous oxygen therapy should be prescribed for patients with COPD who have arterial partial pressure of oxygen 55 mm Hg or less, or oxygen saturation 88% or less as measured by pulse oximetry.
  • Pulmonary secretion clearance: careful nasotracheal suction is indicated only in patients with excessive secretions and an inability to expectorate. Mechanical percussion of the chest as applied by a physical or respiratory therapist is ineffective with acute exacerbations of COPD.
  • Weight loss in obese patients.