Metabolic syndrome: anesthesia for morbid obesity

There is an emerging epidemic of obesity worldwide resulting in a greater number of obese patients presenting for surgery. The combined problems of metabolic disease and mechanical impairment from excess tissues present a variety of problems for the anesthesiologist. Obesity is associated with nonalcoholic fatty liver disease, dyslipidemia, hyperglycemia and type 2 diabetes. Metabolic syndrome, a constellation of findings associated with visceral obesity, appears to confer additional long-term risk. To date no intervention has proven effective in reducing perioperative risk, although statin therapy is promising. Obese patients are more difficult to intubate in the 'sniffing' position, but placed in the 'ramped' position there is no evidence that this risk is greater than in the general population. Obstructive sleep apnea is associated with adverse postoperative outcomes. Much research has focused on preventing postoperative atelectasis. Preoxygenation with continuous positive airway pressure (CPAP), recruitment maneuvers, intraoperative positive end-expiratory pressure of at least 8 cmH2O and postextubation CPAP appear to improve postoperative pulmonary function. Current studies have focused on the immediate impact of obesity on anesthesia and postoperative care. Future research will focus primarily on perioperative metabolic optimization.