ABSTRACT

The risk of deep vein thrombosis and pulmonary embolism in obesity is twice that in normal subjects. Postoperative pulmonary embolism occurs in up to 5% of patients under­ going weight-reduction surgery. It is difficult to make a definitive diagnosis of pulmonary embolism in the obese patient because the overlying adipose tissue and small lung volume makes it hard to read V/Q scans. Recurrent or chronic pulmonary embolism is one of the causes of pulmonary hypertension in obesity. A second cause is pulmonary arterial vasoconstriction consequent to alveolar hypoxia in OHS. A third cause of pulmonary hypertension is a drug or drugs taken to suppress appetite. Two of the more effective appetite suppressants, fenfluramine and dexfenfluramine, were withdrawn from the market in 1997 because they appear to cause heart valve lesions as well as persistent and even fatal pulmonary hypertension.