Summary
Highlights
COPD stands for Chronic Obstructive Pulmonary Disease, also known as Chronic Obstructive Lung Disease (COLD). It's characterized by chronic airway limitation and inflammation that is irreversible. Historically, COPD included chronic bronchitis, emphysema, and asthma, but asthma was removed because it is treatable.
Patients with COPD struggle to fully exhale due to a loss of elasticity in their alveoli, often caused by inflammation of the bronchi or excessive mucus production. The primary causes of COPD include smoking (including passive smoking), occupational exposure to dusts, chemicals, and pollutants (e.g., asbestos, radon), and genetic predisposition, specifically a deficiency in alpha-1 antitrypsin.
Chronic bronchitis is characterized by chronic inflammation of the bronchial trees, leading to excessive mucus production, hacking cough, and recurrent infections. Patients are often referred to as 'blue bloaters' due to signs like cyanosis (blueness), hypoxia, polycythemia (increased RBCs), a long-term productive cough, unusual breath sounds (crackles, rhonchi, wheezes), and peripheral edema caused by right-sided heart failure (cor pulmonale). A productive cough lasting at least 3 months for two consecutive years is a diagnostic criterion.
Emphysema results from alveolar destruction and loss of elastic recoil, leading to air trapping in the lungs. Patients are often called 'pink puffers' due to their pinkish skin, pursed-lip breathing, and increased chest size (barrel chest) from hyperinflation. They are typically thin, have decreased exercise tolerance, severe dyspnea, and a quiet chest upon auscultation due to trapped air. Diagnosis also reveals hyperinflation and a flattened diaphragm on X-ray, leading to air hunger and hyperventilation, often using accessory muscles for breathing. Oxygen therapy should be less than 3 L/min for these patients.
Key diagnostic tests for COPD include spirometry, which measures forced expiratory volume in 1 second (FEV1), and Arterial Blood Gas (ABG) analysis to assess for hypoxemia and chronic compensated respiratory acidosis. A patient with COPD who has been smoking for more than 30 years is at increased risk.
ABG interpretation uses the ROME (Respiratory Opposite, Metabolic Equal) mnemonic. This involves evaluating pH, HCO3 (metabolic), and PCO2 (respiratory). Normal pH is 7.35-7.45, HCO3 is 22-26, and PCO2 is 35-45. Respiratory imbalances are opposite to pH (e.g., high PCO2 = acidic pH), while metabolic imbalances are equal to pH (e.g., high HCO3 = alkalotic pH). Compensation is classified as fully compensated (normal pH), partially compensated (no normal values), or uncompensated (one normal value other than pH).
Specific conditions are linked to different acid-base imbalances. Respiratory acidosis (CARPA) includes COPD, atelectasis, respiratory failure, pneumonia, and aspiration. Respiratory alkalosis (HIGH VP) involves hypoxemia, hyperventilation, ventilator use, and pain. Metabolic acidosis ('AS') is often due to diarrhea, DKA, renal failure, and increased uric acid. Metabolic alkalosis (VANDY) results from vomiting, antacid use, nasogastric suction, diuretics, and excessive bicarbonate.
Nursing management for COPD patients includes positioning (high fowlers, semi-fowlers, or tripod position), and avoiding opioids and benzodiazepines during exacerbations due to their respiratory depressant effects. Increased fluid intake (2-3L) and comfort measures are also crucial. Medical management involves corticosteroids (e.g., dexamethasone, hydrocortisone) to reduce inflammation, typically given via inhalers. Bronchodilators are also used to relax airways and treat air trapping. These include short-acting (SABA) and long-acting beta agonists (LABA) like albuterol, formoterol, and salmeterol, as well as short-acting (SAMA) and long-acting muscarinic antagonists (LAMA) such as ipratropium and tiotropium, which decrease muscarinic secretions. Albuterol specifically treats acute symptoms and exacerbations.