Preoperative assessment of respiratory function in severely obese patients undergoing biliopancreatic diversion

Since severe obesity is often associated with a pulmonary function defect and abdominal surgery increases the risks of respiratory postoperative complications (RPC), an increased incidence of RPC might occur after bariatric operations. A cohort of 146 severely obese patients undergoing biliopancreatic diversion (BPD) was retrospectively evaluated for the occurrence of RPC. Respiratory function was evaluated prior to BPD from the quotient between measured and predicted values of forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)) and the Tiffeneau index (TI: FEV(1)/FVC). In this cohort of obese individuals the BMI degree prior to the operation was totally unrelated to the standardized values of TI and to the presence of restrictive or obstructive pulmonary disease. Globally, a very low rate of RPC (7.5%) was found; in patients with suspected restrictive pulmonary impairment, a high occurrence of RPC was observed (p < 0.05). When data are controlled for preoperative BMI values, smoking status and presence of sleep apnoea, a logistic regression model indicates that respiratory function data cannot predict the occurrence of RPC after bariatric surgery.