Comparison of dexmedetomidine and morphine versus plain ropivacaine 0.2% for myofascial infiltration in thoracolumbar spinal fusion: a double-blind randomized trial

Study Design: Prospective double-blinded randomized controlled trial. Purpose: This study aimed to compare the effect of adding dexmedetomidine or morphine to 0.2% ropivacaine on total postoperative opioid consumption and to compare time to first rescue analgesia, Visual Analog Scale (VAS) scores, and side effect profiles between groups. Overview of Literature: Spine fusion surgery involves cutting or retracting the paraspinal muscles, causing moderate to severe postoperative pain. Neuroanesthesia aims to ensure adequate safety and analgesia, thereby facilitating immediate postoperative neurological examination, mobilization, and early hospital discharge. Methods: A double-blinded, randomized controlled trial was conducted involving 66 consenting patients upon obtaining approval from the Institutional Ethics Committee. Patients were randomly allocated into three groups (ropivacaine [R], ropivacaine with dexmedetomidine [RD], and ropivacaine with morphine [RM], 22 patients per group). The operating surgeon administered the allocated study drug at the end of surgery according to group assignment. Results: All the groups were comparable in terms of demographic characteristics, American Society of Anesthesiologists class, and number of spine segments operated on. Mean total postoperative opioid consumption, time to first request for rescue analgesia, and total VAS score were significantly lower in groups RD and RM compared with group R, and in group RM compared with group RD. Similar results were observed when patients were analyzed based on the number of spinal segments operated on. Conclusions: Morphine as an adjuvant to ropivacaine showed superior efficacy compared with dexmedetomidine-ropivacaine or ropivacaine alone in patients undergoing elective thoracolumbar spine fusion surgery.