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

Abstract

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.