Effect of magnesium sulfate with ketamine infusions on intraoperative and postoperative analgesia in cancer breast surgeries: a randomized double-blind trial

Abstract

Background: Opioids are the cornerstone in managing postoperative pain; however, they have many side effects. Ketamine and Magnesium (Mg) are NMDA receptor antagonists used as adjuvant analgesics to decrease postoperative opioid consumption.

Objective: We assumed that adding Mg to ketamine infusion can improve the intraoperative and postoperative analgesic efficacy of ketamine infusion alone in cancer breast surgeries.

Methods: Ninety patients aged between 18 and 65 years and undergoing elective cancer breast surgery were included in this prospective randomized, double-blind study. Group K received ketamine 0.5.ßmg.kg^...1 bolus then 0.12.ßmg.kg^...1.h^...1 infusion for the first 24.ßhours postoperatively. Group KM: received ketamine 0.5.ßmg.kg^...1 and Mg sulfate 50.ßmg.kg^...1, then ketamine 0.12.ßmg.kg^...1.h^...1 and Mg sulfate 8.ßmg.kg^...1.h^...1 infusions for the first 24.ßhours postoperative. The primary outcome was the morphine consumption in the first 24.ßhours postoperative, while the secondary outcomes were: intraoperative fentanyl consumption, NRS, side effects, and chronic postoperative pain.

Results: Group KM had less postoperative opioid consumption (14.12.ß...ß5.11.ßmg) than Group K (19.43.ß...ß6.8.ßmg). Also, Group KM had less intraoperative fentanyl consumption. Both groups were similar in postoperative NRS scores, the incidence of side effects related to opioids, and chronic neuropathic pain.

Conclusion: Adding Mg to ketamine infusion can safely improve intraoperative and postoperative analgesia with opioid-sparing effect in cancer breast surgery.

Trial registration: ClinicalTrials.gov NCT04111848.

Keywords: Cancer breast; Infusion; Ketamine; Magnesium sulfate.