Comparison of dexmedetomidine and ketamine in adjuvant with morphine for postoperative pain management following lumbar fusion surgery

Background: Postoperative pain leads to increased opioid consumption and associated adverse effects. Adjuvant analgesia can improve pain management and reduce opioid consumption. This study aimed to compare the analgesic effects of adjuvants of dexmedetomidine and ketamine with morphine in patients with lumbar fusion. Patients and methods: In this double-blind randomized clinical trial, patients undergoing elective lumbar fusion surgery were included. These patients were randomly divided into three groups. Group D received 50 mu g dexmedetomidine and 20 mg of intravenous morphine, group K received 50 mg of ketamine and 20 mg of intravenous morphine, and control group C received 20 mg of intravenous morphine with normal saline (100 cc) in the form of PCA (patient-controlled analgesia) pump. The severity of pain after surgery was assessed using a visual analog scale (VAS) 2, 6, and 24 postoperative hours. Nausea and vomiting after the surgery, the amount of drug consumption from the PCA pump, and the duration of hospital stay were also evaluated. Results: Of 196 patients included in the study, 69.4 % were males and 30.6 % were females. At 2,6 and 24 postoperative hours, the pain was significantly less in group D, compared to groups K and C, p < 0.05. However, in all three groups, pain was significantly reduced at all time intervals, p < 0.05. Group C had significantly the greatest incidence of postoperative nausea and vomiting, ileus, and prolonged hospitalization, p < 0.05. Conclusions: The results of this study showed that postoperative pain management with the adjuvant of dexmedetomidine and morphine is most effective in terms of pain, adverse effects, hospitalization, and patient satisfaction. It is also superior to ketamine and morphine adjuvant and morphine alone, respectively.