Effect of intraoperative ketamine on morphine consumption during 24 postoperative hours of obese patients undergoing laparoscopic gastric sleeve. Randomized controled clinical trial

Introduction: Ketamine has been used in sub-anesthetic doses in non-obese patients suggesting that its use decreases postoperative morphine consumption. however, the evidence in the literature is contradictory. Objective: To determine the effect of intraoperative ketamine on postoperative morphine consumption during the first 24 hours postoperatively in obese patients operated on laparoscopic gastric sleeve. Material and method: Controlled, randomized, double-blind, unicentric clinical trial, approved by the health research ethics committee of our institution. We included obese patients 18 to 60 years old of both sexes, obese with an indication of laparoscopic Gastric Sleeve, ASA II. The intervention was randomized to an experimental group (ketamine) and a placebo (saline).Ketamine 0.5 mg/kg was administered as a loading dose after anesthetic induction and then an infusion of 0.1 mg/kg/h until the end of surgery. On admission to the Post Anesthesia Unit, in both groups, a morphine infusion pump was started, programmed with 1 mg of bolus and with a time block of 10 minutes between doses, for 24 hours. Results: 63 patients were analyzed. Thirty-two patients in the ketamine group and 31 in the placebo group. The median morphine consumption of the ketamine group was 20 mg (ric 11 mg / min: 5-max.: 57 and 19 mg (ric: 11 / min.: 8-max.: 82) in the placebo group, nonsignificant statistical difference (p = 0.412). No statistical differences were found between the groups in terms of adverse effects to opioids, sedation and ambulation Conclusion: The administration of ketamine in laparoscopic gastric sleeve surgery does not decrease morphine consumption during the first 24 postoperative hours, nor the proportion of adverse effects to opioids and does not delay the ambulation of postoperative patients in this studio. This study was carried out with funds from the Academic Department of Clinica Las Condes. None of the researchers participating in this study declared conflicts of interest of any kind.