Comparison of the effect of intraoperative dexmedetomidine versus ketamine on postoperative analgesia in fracture femur patients operated under subarachnoid block – A prospective randomized double-blind controlled trial

Intravenous sedation during spinal anesthesia has the advantages of increased duration of spinal anesthesia and better postoperative pain control. The aim of this study was to compare the effect of intravenous bolus and infusion of dexmedetomidine versus ketamine given intraoperative on the postoperative analgesia in fracture femur patients operated under subarachnoid block. In this prospective randomized double-blind controlled study, 75 patients aged 18–65 years posted for elective surgery were selected and randomly divided into three groups to receive ketamine (group K), dexmedetomidine (group D), and saline (control group C). Postoperative pain was evaluated using the numerical rating scale (NRS). The duration of analgesia and the amount of analgesic consumption were also recorded. Student’s t-test and Chi-square test were used to compare the two groups, and one-way ANOVA with posthoc analysis was performed for comparison of the three groups. Patients in the ketamine group had better postoperative analgesia as assessed by decreased pain (on the NRS scale) and decreased need for postoperative rescue analgesics (P < 0.001). The duration of sensory block and motor block was prolonged in group K as compared to the other two groups (P < 0.001). Intraoperative use of intravenous ketamine was superior to dexmedetomidine for postoperative analgesia in fracture femur patients operated under subarachnoid block.