Multimodal Intravenous Analgesia Using Half-dose of Ketamine, Lidocaine and Magnesium Sulfate provides Efficient Postoperative Analgesia for patients undergoing Major Abdominal Surgery: Randomized Controlled Study

Background: Evaluation of safety and efficacy of multimodal intravenous analgesia using lidocaine, ketamine, and magnesium sulfate (MS) in half of the documented doses compared to opioid-based and epidural analgesia after major abdominal surgery (MAS).Patients & Methods: 135 patients were randomly divided according to postoperative (PO) analgesia into Group-O received nalbuphine infusion (65 µg/kg/h), Group-E received epidural analgesia as initial dose (15 ml of 0.5% bupivacaine) followed by intermittent manual boluses and Group-M received multimodal analgesia as ketamine (90 µg/kg/h), lidocaine (1 mg/kg/h) and MS (7.5 mg/kg/h) infusions. The study outcomes included evaluation of the analgesia efficacy, the frequency and severity of drug- related side effects of the multimodal analgesia in comparison to systemic opioid and epidural analgesia.Results: 33 patients of groups-E and-M did not require PO analgesia and 57 patients requested it once, while all patients of Group-O required PO analgesia with significantly higher frequency. Patients of groups-E and-M showed significantly longer time till having pain necessitate receiving PO analgesia than patients in Group-O with significantly higher total dose of morphine. Pain scores were significantly lower in groups-E and-M compared to Group-O. Eighteen patients developed drug-related side effects with significantly higher frequency in Group-O. Surgeons and patients' satisfaction scoring was significantly higher by PO analgesia provided for groups-E and-M. Conclusion: Multimodal analgesic infusion in the used doses is safe and effective opioid-sparing analgesia for patients undergoing MAS and can substitute opioid-base or epidural analgesia.