Comparison of Intraoperative Low-Dose Ketodex and Fentanyl Infusion for Postoperative Analgesia In Spine Surgery: A Prospective Randomized Double-Blind Study

<bold>Study design: </bold>Prospective randomized double-blind study.<bold>Purpose: </bold>To assess the analgesic effects of the combination of a low-dose ketamine and dexmedetomidine (ketodex) infusion and compare it with that of fentanyl for postoperative analgesia after spine surgeries.<bold>Overview of literature: </bold>Adequate pain management following spine surgeries is crucial. Approximately 57% of patients experience inadequate pain control in the first 24 hours following elective spine surgery, which is attributable to the extensive soft tissue and muscle damage.<bold>Methods: </bold>The study included 60 patients graded American Society of Anesthesiologists I and II and scheduled for thoracolumbar spine surgery involving >3 vertebral levels. The patients were divided into two groups: group KD (ketodex) and group F (fentanyl). The primary objective was to compare the postoperative analgesic requirements among the groups. The secondary objectives included a comparison of the intraoperative anesthetic requirements, postoperative pain scores, hemodynamic parameters, side effects of the study drugs, and the duration of post-anesthesia care unit stay of both the groups.<bold>Results: </bold>Ketodex use prolonged the mean time to first rescue analgesia (22.00 +/- 2.30 hours vs. 11.69 +/- 3.02 hours, p <0.001) and reduced the requirement of rescue analgesics in the first 24 hours postoperatively compared to fentanyl use (70.00 +/- 8.16 mu g vs. 113.31 +/- 36.65 mu g, p =0.03). The intraoperative requirement of desflurane was comparable between the groups (p >0.05). The postoperative pain scores were significantly lower in the group KD than in group F at most timepoints (p <0.05). Patients in group KD had a shorter post-anesthesia care unit stay than group F did (p <0.001).<bold>Conclusions: </bold>Low-dose ketodex could be a safe substitute for fentanyl infusion when employed as an anesthetic adjuvant for patients undergoing thoracolumbar spine surgeries involving >3 vertebral levels to achieve prolonged analgesia without any opioidrelated side effects.