Intraoperative Dexmedetomidine has no Effect on Postoperative Pain Scores for Posterior Spinal Fusion

Posterior Spinal Fusion (PSF) for idiopathic scoliosis results in severe postoperative pain. At our institution, a protocol for postoperative analgesia is followed, but anesthetic maintenance is decided by the anesthesiologist. Previous studies have shown that postoperative use of dexmedetomidine may improve analgesia for these patients, but the effect of intraoperative dexmedetomidine on postoperative pain scores remains unknown.

We sought to retrospectively compare pain scores from the Postoperative Anesthesia Care Unit (PACU) and from PACU discharge until midnight between PSF patients who did and did not receive intraoperative dexmedetomidine.

After obtaining IRB approval, we retrospectively identified 79 patients aged 10-17 years who had undergone PSF for idiopathic scoliosis from June 2015-August 2018 and who received intrathecal morphine. Patients were then divided into two groups based on whether or not they received intraoperative dexmedetomidine. A multivariable linear regression model was constructed with the dependent variable of highest PACU pain score and exposure of interest intraoperative dexmedetomidine use. Secondary analyses were conducted similarly within those who received dexmedetomidine to examine the effects of dose on PACU pain scores, using a p-value < 0.05.

After adjusting for age, weight, sex, levels fused, intrathecal morphine, diazepam, and ketamine doses, there was no statistically significant difference in average PACU pain scores between those who did and did not receive intraoperative dexmedetomidine (β = -0.85, 95% CI: -2.48, 0.68; p = 0.31).

Intraoperative use of dexmedetomidine during posterior spinal fusion for adolescent idiopathic scoliosis appears to have no effect on postoperative pain scores.