Chronic Obstructive Pulmonary Disease: Clinical Case
Chronic Obstructive Pulmonary Disease Case |
HPI: RH is a 65 year-old man who presents to your office with shortness of breath. He has had recurrent bouts of shortness of breath, especially after any strenuous exercise, for 2 years. His symptoms have been progressive to the point that he now has trouble climbing a flight of stairs. The current difficulties began 2 days ago while out on a walk with his wife. Since then his coughing and dyspnea has been progressive, and he is coughing up even more purulent sputum than usual. He denies fever, but has noted some swelling in both feet. PMI: RH has a history of hypertension, increased cholesterol. He also has asthma. His medications include an albuterol inhaler he uses when he has wheezing or shortness of breath, but it has done little to settle his current symptoms. He also takes a statin to control his cholesterol. P/E: RH is in moderate respiratory distress, using his accessory muscles to breathe. Vitals: HR 90; RR 32; BP 135/90 mm Hg; Temp 37°C (98.6°F); SaO2 88%. Examination of his head and neck reveals elevated JVP. RH is thin but has a barrel-shaped chest. Heart sounds are normal, but expiratory wheezes are heard throughout his lung fields. His capillary refill is normal but there is slight cyanosis of his nail beds. There is edema to a level just above his ankles. Investigations: You order a chest X-ray on your patient, RH (see Figure 1). |
Figure 1 |
| Question | Your Answer |
What is the most likely diagnosis? |
Chronic obstructive pulmonary disease (COPD), a progressive and irreversible lung disease. |
What are the most common variants of this condition and which does RH likely have? |
Chronic bronchitis is characterized by recurrent inflammation of the bronchial mucosa along with hypertrophy of mucus producing cells. The copious amounts of mucus created affect oxygen exchange and often lead to cyanosis and recurrent lung infections. Emphysema is the other common variant of COPD. In this condition, recurrent irritation and inflammation of the alveolar walls leads to them breaking down with a loss of surface area, fibrosis, and thickening of bronchial walls that causes obstruction and atelectasis. Given this patient is cyanotic and has significant sputum production, he most likely has chronic bronchitis (although often patients have varying degrees of each). |
What are the typical chest X-ray findings associated with air trapping and hyperinflation? |
As the chest circumference expands, the anterior-posterior diameter increases. Lung expansion also depresses the diaphragm revealing hyperinflation (see Figure 1). |
What would happen if you gave significant concentrations of oxygen to this patient? |
The chronic high levels of PaCO2 have nullified the hypercapneic respiratory drive, leaving this patient dependent on the hypoxic drive. Therefore, it is important that his O2 sats not increase too highly, or his respiratory drive will stop and he will become apneic. |
Why is he cyanotic? |
The inflammation, hypertrophy, and increased secretions have decreased oxygen diffusion across the alveolar walls, leading to unoxygenated hemoglobin (Hgb) returning to the left side of his heart (increase A-a gradient and ventilation-perfusion (V/Q) mismatch). |
Explain the underlying process causing his elevated JBP and peripheral edema |
The inflammation, hypertrophy, and obstruction in his airways has increased his pulmonary vascular pressure to the point that he has gone into right-sided heart failure. As the pressure in his lung vasculature has increased, it has backed up the blood flow entering his right atrium through the superior (JVP) and inferior (peripheral edema) vena cava. |