Association of metabolic syndrome and surgical factors with pulmonary adverse events, and longitudinal mortality in bariatric surgery

Abstract

Background: Postoperative pulmonary complications (PPC) in bariatric surgery have not been well studied. Additionally, many bariatric patients suffer from the metabolic syndrome (MetS), contributing to surgical risk. We examined the incidence of PPC and MetS in a large national bariatric database. Furthermore, we analysed the relationships between morbidity, mortality, PPC, MetS, and several other comorbidities and also surgical factors. Methods: The Bariatric Outcomes Longitudinal Database (BOLD™) is a registry that includes up to 365 day outcomes. We analysed data between January 2008 and October 2010. The PPC tracked included pneumonia, atelectasis, pleural effusion, pneumothorax, adult respiratory distress syndrome, and respiratory failure. A composite pulmonary adverse event (CPAE) included the occurrence of any of these. MetS was defined as the combination of hypertension, dyslipidaemia, and diabetes mellitus. The association of MetS and additional comorbibities, procedural data, and patient characteristics with CPAEs was examined with appropriate statistical tests. Results: A total of 158 405 patients had a low incidence of PPC (0.91%) and a low mortality (0.6%) after bariatric surgery. MetS was prevalent in 12.7%, and was a significant risk factor for CPAE and mortality. Age, BMI, ASA physical status classification, surgical duration, procedure type, MetS (P<0.001), and additional comorbidities were significantly associated with CPAEs. Conclusions: The incidence of PPC was low after bariatric surgery. Increasing age, BMI, ASA status, MetS, obstructive sleep apnoea, asthma, congestive heart failure, surgical duration, and procedure type were independently significantly associated with PPC. Pulmonary complications and MetS were significantly associated with increased postoperative mortality.