Background: In obese patients functional residual capacity comes down with a possible hypoxemia in postoperative period. In fact many studies has been begun to determine optimum ventilation regulation and the best position for these patients, but the question has not been solved. As remifentanil can reduce of 50% the inhalatory anaesthetic request and reverse Trendelemburg position is extremely useful for these patients, we hypothesized that use of a continuous remifentanil infusion during balanced anaesthesia with sevoflurane, BIS-titrated, associated to reverse Trendelem-burg position could facilitate emergence from anaesthesia in obese patients undergoing laparascopic cholecystectomy.
Methods: We studied 40 patients, ASA II class, with higher than 30 kg/m2 body mass index, undergoing to laparoscopic cholecystectomy. All the patients, in operating room, received standard monitoring and BIS sensor application. All the data were continuously collected. Induction of anaesthesia has been with a refracted bolus in 120 sec of remifentanil 1 mg/kg, followed by propofol 1.5 mg/kg and cisatracurium 0.15 mg/kg. Maintenance of anaesthesia has been by balanced anaesthesia with continuous remifentanil infusion, ventilating patients with sevoflurane in oxygen and air. Patients were randomized into two homogenous groups. Into the control group has been varied sevoflurane inspiratory concentration on the ground of BIS value (from 0.3% to 3%), while into remifentanil group remifentanil infusion has been varied (from 0.25 to 2 mg/kg/min) to maintain medium pressure values which don't stray more than 25% from basal values, on the ground of BIS values. On pre-established times of operation, respiratory mechanics and blood gases were examined.
Results: As it was to expect, sevoflurane concentration variations resulted very high in control group compared to remifentanil group. Awakening time, extubation, orientation and transfer to PACU (postanaesthesia care unit) resulted significantly lower than remifentanil group.
Conclusions: Concluding, remifentanil infusion, BIS-titrated, facilitates awakening times from balanced anaesthesia with Sevoflurane in obese patients, submitted to laparoscopic cholecystectomy.