A 68-year-old man comes to the emergency department due to progressively worsening shortness of breath for 2 days. He has had a week of low-grade fever, runny nose, and productive cough. The patient's other medical problems include coronary artery disease, hypertension, and hyperlipidemia. He was hospitalized a year ago for acute myocardial infarction and was treated with drug-eluting stent placement in the left anterior descending artery. The patient has a 40-pack-year smoking history and quit after the myocardial infarction. His temperature is 37.2 C (99 F), blood pressure is 140/90 mm Hg, pulse is 90/min, and respirations are 22/min. The patient appears to be in mild respiratory distress. He uses accessory respiratory muscles for breathing but can speak in full sentences. Neck veins are mildly distended, especially during expiration. Lung auscultation shows decreased breath sounds and bilateral wheezes. Heart sounds are distant. Plasma B-type natriuretic peptide level is 88 pg/mL (normal 0-100 pg/mL). Chest x-ray is shown below. Which of the following is the most likely cause of this patient's presentation?

Question

A 68-year-old man comes to the emergency department due to progressively worsening shortness of breath for 2 days.  He has had a week of low-grade fever, runny nose, and productive cough.  The patient's other medical problems include coronary artery disease, hypertension, and hyperlipidemia.  He was hospitalized a year ago for acute myocardial infarction and was treated with drug-eluting stent placement in the left anterior descending artery.  The patient has a 40-pack-year smoking history and quit after the myocardial infarction.  His temperature is 37.2 C (99 F), blood pressure is 140/90 mm Hg, pulse is 90/min, and respirations are 22/min.  The patient appears to be in mild respiratory distress.  He uses accessory respiratory muscles for breathing but can speak in full sentences.  Neck veins are mildly distended, especially during expiration.  Lung auscultation shows decreased breath sounds and bilateral wheezes.  Heart sounds are distant.  Plasma B-type natriuretic peptide level is 88 pg/mL (normal 0-100 pg/mL).  Chest x-ray is shown below.  Which of the following is the most likely cause of this patient's presentation?

Quizplus · Accepted Answer

Explanation: This elderly patient with a long smoking history likely has undiagnosed chronic obstructive pulmonary disease (COPD). His presentation is consistent with an acute exacerbation of COPD, characterized by a change in ≥1 of the following: Cough severity or frequency Volume or character of sputum production Level of dyspnea Physical examination is often remarkable for wheezing, tachypnea, prolonged expiration, and use of accessory respiratory muscles. Jugular venous distension (JVD) may be observed, especially during expiration, due to increased intrathoracic pressure. Hyperinflation can be seen on chest x-ray and explains the distant heart sounds on auscultation. Upper respiratory infection (URI) is the most common trigger of COPD exacerbation; in this patient, URI is suggested by the 1-week history of low-grade fever, runny nose, and productive cough. Hyperinflation (Choice A) Acute asthma exacerbation can present similarly to COPD exacerbation. However, in an elderly patient with significant smoking history and no history of asthma, COPD exacerbation is more likely. (Choice B) Acute decompensated heart failure often presents with dyspnea, orthopnea, cough, peripheral edema, and paroxysmal nocturnal dyspnea. Examination can show an S3, bibasilar crackles with dullness to percussion, and JVD. Chest x-ray typically reveals cardiomegaly and diffuse pulmonary congestion. Elevated B-type natriuretic peptide (BNP) has high sensitivity for acute heart failure decompensation, and BNP <100 pg/mL (present in this patient) is useful in excluding the diagnosis. Chest x-ray (Choice C) Pulmonary embolism can cause dyspnea and tachypnea. However, in this patient, the lack of pleuritic chest pain or tachycardia and the presence of a productive cough, wheezes, and hyperinflation on chest x-ray in the setting of a recent URI are more suggestive of COPD exacerbation. (Choice E) Community-acquired pneumonia presents with dyspnea, pleuritic chest pain, fever, and productive cough. However, focal increased breath sounds and crackles are often present on examination, and chest x-ray usually demonstrates a consolidative alveolar filling process. (Choice F) Subacute cardiac tamponade presents with hypotension, muffled heart sounds, and JVD. This patient's borderline hypertension makes tamponade extremely unlikely. Additionally, the cardiac silhouette on chest x-ray should be enlarged in tamponade. Educational objective: Acute exacerbation of chronic obstructive pulmonary disease (COPD), characterized by an acute worsening of symptoms in a patient with COPD, is commonly triggered by an upper respiratory infection. Examination often reveals wheezes, tachypnea, prolonged expiration, and use of accessory muscles. References: Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease: GOLD executive summary. (http://www.ncbi.nlm.nih.gov/pubmed/22878278) The diagnostic accuracy of the natriuretic peptides in heart failure: systematic review and diagnostic meta-analysis in the acute care setting. (http://www.ncbi.nlm.nih.gov/pubmed/25740799)

A 68-Year-Old Man Comes to the Emergency Department Due to Progressively