Bariatric surgery provides substantial and prolonged weight reductions. Complications associated with bariatric surgery have been well-defined; although, the risk of developing these complications is unclear. Maximal oxygen consumption (VO2max), determined by cardiopulmonary exercise testing (CPX), is a measure of aerobic fitness. The aim of this study was to assess the association between VO2max and complications encountered with bariatric surgery.
CPX was performed on 109 consecutive patients with morbid obesity undergoing laparoscopic Roux-en-Y gastric bypass surgery. Chart review was performed by reviewers blinded to the CPX results.
Mean age was 46.0±10.4 years and 82 (75.2%) were female. Mean body mass index (BMI) was 48.1±7.5 kg/m2 and 50.4±6.0 kg/m2 for women and men, respectively p=0.17. VO2max measurements ranged from 6.8 to 27.7 ml/kg/min. Patients were stratified by tertile of VO2max. Mean VO2max in the first tertile was 13.7±2.1, second tertile was 17.1±0.8, and third tertile was 21.3±2.1. Patients in the first tertile experienced longer operative room times, p=0.04, and greater number of ICU days, p=0.05. Composite complication rate, defined as death, unstable angina, myocardial infarction, venous thromboembolism, infection, gastrointestinal bleeding, renal failure or stroke, occurred in 2/72 (2.8%) and 6/37 (16.2%) above and below a peak oxygen consumption of 15.8 ml/kg/min (lowest tertile) respectively, p=0.02. No complications occurred in patients with both VO2max ≥ 15.8 ml/kg/min and BMI < 45 kg/m2. In comparison to other cardiorespiratory parameters, the area under the receiver operating characteristic curve was highest for VO2max in predicting complications (AUC=0.72, p<0.0001.) Multivariate analysis found the first tertile of VO2max to have an odds ratio of 10.9 (95% CI 1.01-73.80, p=0.04) for the prediction of postoperative complications.
Poor aerobic fitness, determined by a low VO2max, predicted complications associated with bariatric surgery.
VO2max should be determined prior to bariatric surgery to assess the risk of surgical complications. Cardiorespiratory fitness is potentially modifiable and should be optimized prior to elective surgery with the goal of reducing surgical complications.
Justin Trivax, None.