The effect of combined remifentanil and low dose ketamine infusion in patients undergoing laparoscopic gastric bypass

BackgroundThe choice of anesthesia in morbidly obese patients remains controversial. We evaluated the effect of continuous low dose ketamine infusion combined with remifentanil and propofol in patients undergoing laparoscopic gastric bypass, on hemodynamic stability, postoperative analgesic requirement and recovery profile.Methods60 patients aged 25–50 years, allocated into 2 groups. Group I: received continuous infusion of (propofol 6–10 mg/kg/h + remifentanil 0.2 μg/kg/min + saline). Group II: received continuous infusion of (propofol 6–10 mg/kg/h + remifentanil 0.2 μg/kg/min+ ketamine 1μg/kg/min). All patients recieved intravenous morphine by patient controlled analgesia (PCA) postoperatively.Mean blood pressure and HR, duration of anesthesia and surgery recorded. Bispectral index, total amount of propofol and remifentanil used intraoperative were measured. In the recovery room, time to response to verbal commands was recorded, subjective pain scores were obtained with a scale from 0–10. Postoperative nausea and vomiting, hallucinations were recorded. Early pain perception and total consumption of morphine in 24 h recorded.ResultsDuring anesthesia, mean arterial blood pressure and heart rate were decreased in group I compared with group II. The amount of propofol required to maintain the target BIS was lower in group II compared with group I . The amount of intraoperative boluses of remifentanil required to maintain hemodynamics was lower in group II compared with group I. The amount of PCA morphine at 2 h in the PACU and the first post operative day were lower in group II compared with group I. Pain scores at 1 h and 2 h postoperatively were lower in group II compared to group I. P value <0.05 was considered significant.ConclusionDuring laparoscopic gastric bypass in morbidly obese patients the co-administration of low dose ketamine and remifentanil by continuous infusion provide more hemodynamic stability, satisfactory recovery profile and adequate postoperative pain relieve.