Characteristics of Patients With the Malignant Obesity Hypoventilation Syndrome Admitted to an ICU

Marik PE et al. – Malignant obesity hypoventilation syndrome (MOHS) is a serious multisystem disorder with a high mortality that appears to be relatively common, frequently misdiagnosed, and inadequately treated.

Methods

• The authors reviewed the hospital records of all patients who were admitted to the ICU over an 8-month period, with a body mass index (BMI) greater than 40kg/m² and a PaCO2 greater than 45mmHg.
• They excluded patients with musculoskeletal disease, intrinsic lung disease, and those with >20 pack-year smoking history.

Results

• Sixty-one patients (8% of all admissions) met the inclusion criteria for the study.
• The patients’ mean BMI was 48.9±8.6kg/m².
• The patients’ mean age was 59±11; 47 (77%) were female and 56 (92%) were black.
• All patients were admitted to the ICU with hypercapnic respiratory failure.
• The patients had been admitted to the hospital on average 6 times over the previous 2years; 75% had been erroneously diagnosed and treated for chronic obstructive pulmonary disease (COPD)/asthma and 86% had been treated with diuretics for congestive cardiac failure.
• All patients had type 2 diabetes and the metabolic syndrome.
• Three patients had a tracheotomy in place at admission and required mechanical ventilation.
• All of the remaining patients were treated with noninvasive bilevel positive airway pressure (BiPAP), with 23 patients failing BiPAP and requiring mechanical ventilation.
• Seven patients had a tracheotomy performed.
• On the basis of unexplained abnormalities of liver function tests, 39 patients (64%) were presumptively diagnosed with nonalcoholic steatohepatitis (NASH).
• Pulmonary function tests were suggestive of a restrictive pattern in all patients tested.
• By echocardiography 43 (71%) patients had left ventricular hypertrophy and 37 (61%) patients had features of left ventricular diastolic dysfunction.
• Forty-seven (77%) patients had pulmonary hypertension, which was moderate to severe (pulmonary systolic pressure >45mmHg) in 25 cases.
• All patients had an elevated C-reactive protein (9.4±6.9mg/dL), and all but 1 were vitamin D deficient (13.5±8.5ng/mL).
• Eleven patients (18%) died during the index hospitalization.

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