A 62-year-old man seeks your advice for management of his COPD. He is a former 60-pack-year smoker, but stopped smoking 3 years ago. He uses inhaled albuterol when he feels particularly short of breath. He has noticed mild peripheral edema. He has diabetes mellitus, hypertension, and peripheral vascular disease. For these conditions he takes metformin, HCTZ, lisinopril, and cilostazol. Physical examination reveals a thin man who appears older than his stated age. His BP is 136/78, HR is 88, and RR 18. Room air O2 saturation is 85%. He has distant breath sounds, but no rales, rhonchi, or wheezes. What treatment is most important in his overall health status?
Oxygen treatment (as close to 24 hours a day as possible) is the one active treatment modality that has been shown to decrease mortality in COPD. Interestingly, it decreases the incidence of sudden death. This effect is presumably due to the beneficial effect of oxygen on cor pulmonale and right heart strain. It is important to emphasize to the patient that they should use the oxygen continuously, not just at times of increased dyspnea. Several treatments (inhaled corticosteroids, long-acting bronchodilators) are symptomatically useful and may slow progression of functional loss but have not been shown to prolong life. Pulmonary rehabilitation can increase functional status but does not improve parameters such as FEV1 or mortality. The number of exacerbations is an important determinant of functional decline in COPD, but preventing them is difficult. Prompt antibiotic treatment of purulent exacerbations decreases the rate of hospitalization but has not been proven to affect mortality. Methods to slow progression of COPD are important research topics, as COPD is approaching cerebrovascular disease as the third leading cause of death in the United States.
A 57-year-old man presents with gradually worsening dyspnea on exertion for the past 6 months. He has a 40-pack-year history of tobacco use. He has noted a minimally productive cough, worse in the mornings, for the past 2 years. He is otherwise healthy, without hypertension, hyper-cholesterolemia, or diabetes mellitus. On physical examination, he is comfortable at rest. His room air oximeter reading is 93%. His neck veins are flat and his cardiac examination is normal. He has no basilar crackles, but breath sounds are distant bilaterally. Chest x-ray shows hyperexpansion without evidence of cardiomegaly or pulmonary congestion. What is the most important next step in staging this patient’s illness?
The Global initiative for chronic Obstructive Lung Disease (GOLD) guidelines recommend the use of spirometric values to standardize the diagnosis and staging of COPD. The diagnosis emphasizes a compatible history and evidence of fixed or incompletely reversible airway obstruction as demonstrated by a ratio of FEV1 to FVC less than 70%. Restrictive lung disease causes a proportional decline in both FEV1 and FVC; so the ratio of the two will remain normal. The stage of COPD is then determined by the decrease in FEV1 (see table). Table: Staging of COPD None of the other tests is recommended in the routine staging or management of COPD. Reliable finger oximeters have replaced ABGs as a means of checking for O2 desaturation. An elevated serum bicarbonate on a chemistry profile may indicate metabolic compensation for a chronic respiratory acidosis; sometimes (but not routinely) ABGs will be necessary to precisely quantify the degree of CO2 retention. Chest CT will demonstrate bullous changes in patients with emphysema but is not part of routine patient care. Patients with COPD will usually have limitation of exercise tolerance, but this can be estimated and followed by clinical history. Echocardiogram can confirm pulmonary hypertension (often indicative of cor pulmonale) in patients with clinical evidence of RV dysfunction but again is not necessary in the routine case. Giving O2 for relief of hypoxia is the best way of preventing mortality from cor pulmonale in these patients.
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