comparison of preoperative ketamine, lidocaine, and magnesium (klm) cocktail versus morphine for postoperative pain management in opioid-abuser patients undergoing distal radius fracture surgery: a double-blinded randomized clinical trial

Background: effective postoperative pain management is critical for patient recovery, particularly in opioid-abuser individuals undergoing distal radius fracture surgery. multimodal analgesia, including preoperative ketamine, lidocaine, and magnesium (klm) combinations, has emerged as a promising alternative to reduce opioid consumption while effectively controlling pain. objectives: this study compares the efficacy and safety of a preoperative klm cocktail versus morphine for postoperative pain management in opioid-abuser patients undergoing distal radius fracture surgery. methods: sixty eligible patients [aged 18 - 65, with a history of opium use (1 - 5 g/day)] were randomly allocated (1:1 ratio) into two groups: the klm group received intravenous (iv) lidocaine (1.5 mg/kg), magnesium (30 mg/kg), and ketamine (0.3 mg/kg) diluted in 50 ml of 0.9% normal saline, administered over 15 minutes preoperatively. the morphine (m) group received iv morphine (0.1 mg/kg) in 50 ml of 0.9% normal saline over the same duration. postoperative pain was assessed using the visual analog scale (vas) upon pacu arrival and at 3, 6, 12, and 24 hours post-surgery. secondary outcomes included 24-hour opioid consumption, adverse effects, and patient satisfaction scores. results: the klm group demonstrated significantly lower pain scores on the numerical rating scale (nrs) at all-time points compared to the morphine group (p < 0.05). additionally, total opioid consumption was 40% lower in the klm group, with a reduction in opioid-related adverse effects such as nausea and sedation. patient satisfaction scores were also significantly higher in the klm group. conclusions: preoperative klm cocktail administration is more effective than morphine in managing postoperative pain in opioid-abuser patients undergoing distal radius fracture surgery. this multimodal approach reduces pain scores, opioid consumption, and adverse effects while improving patient satisfaction. further research is needed to validate its long-term efficacy and safety across diverse surgical populations.