Comparative Study Between Dexmedetomidine with Bupivacaine and Bupivacaine Alone in Erector Spinae Plane Block for Postoperative Pain Control of Posterior Lumbosacral Spine Fixation Surgeries: A Randomized Controlled Trial.

Background: As posterior lumbosacral spine fixation surgeries are common spine procedures done nowadays due to different causes and mostly accompanied with moderate-to-severe postoperative pain, so should find effective postoperative analgesia for these patients. This study aimed to observe analgesic effect of dexmedetomidine combined with bupivacaine versus bupivacaine alone for erector spinae plane block ESPB for postoperative pain control of posterior lumbosacral spine fixation surgeries. Methods: Double-blind randomized controlled study including 90 patients who were randomly allocated into 3 groups (30 patients for each): Dexmedetomidine combined with bupivacaine (DB group), bupivacaine (B group), and saline (control) (S group). US-guided ESPB was performed preoperatively bilaterally in all patients of the 3 groups. All patients received intravenous patient-controlled postoperative analgesia with morphine and 1 gm intravenous paracetamol every 8 hours. Primary clinical outcomes were active (while mobilization) and passive (at rest) visual analog scale (VAS) pain score at first 24 hours measured every 2 hours, opioid consumption (number of PCA presses), and need for rescue analgesia. Other clinical outcomes included active and passive VAS pain score at second 24 hours, measured every 4 hours, opioid consumption, need for rescue analgesia, postoperative opioid side effects, and intraoperative dexmedetomidine side effects as bradycardia and hypotension. Results: Active and passive VAS pain scores, postoperative opioid consumption, need for rescue analgesia, and postoperative opioid side effects were significantly lower in DB group when compared to other groups (B and S groups). There were no additional intraoperative dexmedetomidine side effects as bradycardia and hypotension. The estimated effect-size r was -0.58 and Cohen's d was -1.46. Conclusion: Addition of dexmedetomidine to bupivacaine 0.25% in ESPB for postoperative pain control in patients of posterior lumbosacral spine fixation surgeries resulted in lower active and passive VAS pain scores, decreased postoperative opioid consumption, need for rescue analgesia and postoperative opioid side effects without additional intraoperative dexmedetomidine side effects. Clinicaltrialsgov Identifier: NCT05590234.