Efficacy of Preventive Ketamine on Postoperative Pain

"1. 40 ml volume of bupivacaine 0.25% + ketamine 0.5 mg/kg distributed as 30 ml intraperitoneally and 10 ml as port site infiltration~2. 10 ml normal saline 0.9% will be given intravenous."

"1. 40 ml volume of bupivacaine 0.25% only distributed as 30 ml intraperitoneally and 10 ml as port site infiltration~2. 10 ml volume of ketamine 0.5 mg/kg intravenously will be given after delivering the gastric sleeve and before start closure of port sites."

"1. 40 ml volume of bupivacaine 0.25% only distributed as 30 ml intraperitoneally and 10 ml as port site infiltration~2. 10 ml normal saline 0.9% will be given intravenous."