Obesity and post-operative pain.

Patients underwent elective abdominal surgery for morbid obesity (mean = 154 kgs, n = 55) or cholecystectomy (mean = 71 kgs, n = 54). Post-operative narcotics were transformed into morphine equivalent units (ME). Morbidly obese patients received significantly fewer total doses than cholecystectomy patients and less total mg ME/kg over a five-day period. Sedative use for both groups was comparable. In the morbidly obese patients, preoperative psychiatric and drug usage data predicted 67% of the variance in number of doses and 69% of the variance in total mg ME/kg.