Morbid Obesity: Obscuring the Diagnosis of Aortic Stenosis in a Patient with Cardiogenic Wheezing

Abstract

We report the case of a morbidly obese 65-year-old female who presented with repeated hypotensive episodes following dialysis. She was misdiagnosed as suffering from asthma, and eventually was found to have severe aortic stenosis. Obesity has become a common and formidable obstacle to gathering important diagnostic information in patients. Modern diagnostic lab tests and imaging modalities such as transthoracic echocardiography (TTE) can provide spurious data in the morbidly obese population, which can ultimately lead to misdiagnosis. In this clinical vignette, we discuss the relationship between the basic pathophysiologic mechanisms underlying aortic stenosis and patient clinical presentation. We also review the relevant literature and discuss the impact of obesity on the diagnosis of this condition. CASEA 65-year-old morbidly obese (body mass index of 53.5) woman on chronic intermittent hemodialysis presented to the emergency department (ED) with worsening dyspnea and wheezing provoked by minimal exertion. Her associated symptoms included dry cough, but no chest pain or fever. Although she underwent dialysis two days prior to presentation without complication, over the preceding year she had multiple ED visits for lightheadedness and hypotension following dialysis sessions.Past medical history was also notable for hypertension, type 2 diabetes, and obstructive sleep apnea (OSA). She had been bed-bound and living in an assisted living facility over the prior seven months after suffering from a fractured ankle. The patient reported a recent history of intermittent asthma treated with as-needed nebulized anti-cholinergic/ beta-agonists; however, she had never undergone formal pulmonary function testing. She had no history of tobacco use or abnormal environmental exposures. Ten days prior to presentation, the patient was admitted to the hospital with dyspnea and wheezing in addition to somnolence. On that admission, her PaCO 2 was 72.9 mmHg, and brain natriuretic peptide (BNP) was 86 pg/ml (her baseline PaCO 2 level had been in the mid-60s mmHg, and she had no prior BNP levels drawn). She was treated for presumed asthma exacerbation with oral steroids and nebulizers and also started on nocturnal non-invasive positive pressure ventilation for untreated obesity hypoventilation and OSA. Following discharge, she reported no significant improvement in her symptoms. She was seen again in the ED four days prior to presentation with hypotension following dialysis and was treated successfully with a liter fluid bolus.On arrival, the patient's temperature was 36.8°C, heart rate 68 beats/minute, blood pressure 120/74 mmHg, respiratory rate 22/min, and oxygen saturation 100 % on room air. Physical exam was remarkable for an obese female in no acute distress and oriented × 3, diffuse wheezing in all lung fields, and apparently normal S 1 and S 2 on cardiovascular examination with soft and extremely difficult to appreciate heart sounds. Volume status and jugular venous pressure were difficult to assess given her obesity and ne...

Impact of Body Mass Index on the Accuracy of Physical Examination and MRI of the Shoulder

“…Several studies outside the field of orthopaedics have demonstrated that obesity can affect the reliability of the physical examination. 3 , 4 , 6 , 11 , 22 , 33 …”

“…Several studies outside the field of orthopaedics have demonstrated that obesity can affect the reliability of the physical examination. 3,4,6,11,22,33 Orthopaedic literature on the effect obesity has on physical examination is scarce. Anthropometric measurements of midarm circumference, subscapular, and triceps skinfold thicknesses are on the rise in concurrence with the increase in mean BMI and obesity rates.…”