A 52-year-old man is brought to the office by his wife. According to her, he repeatedly wakes up at night and seems to be choking but falls back asleep quickly. The patient reports fatigue and often falls asleep while reading books or watching television. He had childhood asthma that required inhalers. Other medical conditions include type 2 diabetes mellitus, hypertension, and hyperlipidemia. Medications include metformin, sitagliptin, atorvastatin, amlodipine, and lisinopril. The patient does not use tobacco and drinks alcohol only on weekends. Blood pressure is 150/88 mm Hg and pulse is 80/min. BMI is 34 kg/m². There is no jugular venous distension. Lungs are clear to auscultation. A grade II/VI apical holosystolic murmur is present. There is no organomegaly. Mild bilateral pitting edema is present. What is the most likely cause of this patient's symptoms?

Question

Quizplus · Accepted Answer

11ec25c8_d4bf_a913_bc81_79b4e4d32dd8_MD0003_00 This patient with obesity who has daytime sleepiness and appears to choke at night likely has obstructive sleep apnea (OSA). OSA results from laxity of the pharyngeal musculature, leading to transient upper airway obstruction and nocturnal hypoventilation in the reduced-consciousness setting of sleep. transient upper airway obstruction Typical manifestations include excessive daytime sleepiness, morning headaches, impotence, poor judgment, and depression. A history of snoring and/or periods of apnea or gagging witnessed by bed partners is often reported. Physical examination often demonstrates obesity and increased neck girth, which correlate with OSA severity. Sequelae of untreated OSA include systemic hypertension, pulmonary hypertension, and right-sided heart failure. Although tricuspid regurgitation (holosystolic murmur at the left lower sternal border) may occur with pulmonary hypertension, this patient's holosystolic murmur at the apex suggests mild mitral regurgitation (MR), which can occur from a variety of etiologies (eg, myxomatous degeneration) but is unrelated to pulmonary hypertension. (Choice A) Airway inflammation and hyperresponsiveness in the setting of asthma or chronic obstructive pulmonary disease are common causes of dyspnea. Although this patient has a history of childhood asthma, coughing and wheezing would be expected. (Choice B) Aspiration of gastric contents can occur with gastroesophageal reflux (GERD), which can cause nighttime coughing or choking sensations and often occurs in obese patients. However, GERD often causes reflux symptoms (eg, burning epigastric pain) and would not explain this patient's daytime fatigue. (Choice C) The alveolar-arterial (A-a) oxygen gradient, which reflects the efficiency of oxygen transfer from the alveoli to the blood, is increased with conditions involving ventilation-perfusion mismatch (eg, pulmonary embolism, pneumonia) and impaired gas exchange (eg, interstitial lung disease). In OSA, hypoxia is due to nocturnal hypoventilation rather than impaired oxygen transfer; therefore, although both alveolar and arterial oxygen content are decreased, the A-a gradient is normal. (Choice E) Pulmonary venous congestion from congestive heart failure (CHF) can cause disturbed sleep (ie, paroxysmal nocturnal dyspnea). However, other than mild edema of the lower extremities (possibly from amlodipine), this patient has no jugular venous distension or crackles to suggest CHF. Although severe MR can cause CHF, this patient's soft murmur suggests mild MR (murmur intensity usually correlates with regurgitation severity), which is unlikely to cause CHF. Educational objective: Obstructive sleep apnea is caused by episodic obstruction of the upper airway due to laxity of pharyngeal tissue, resulting in nocturnal hypoventilation. Common manifestations include daytime sleepiness, snoring, and a choking or gagging sensation while sleeping. References: Obstructive sleep apnea, hypertension and cardiovascular diseases. (http://www.ncbi.nlm.nih.gov/pubmed/25761667)

A 52-Year-Old Man Is Brought to the Office by His