Does Dexmedetomidine Affect Opioid Consumption Following Orthognathic Surgery?

Despite its purported analgesic effects, controversy exists regarding dexmedetomidine's efficacy as an opioid-sparing anesthetic adjunct.

The purpose of this study is to measure the association between dexmedetomidine (DEX) administration during orthognathic surgery and postoperative opioid consumption.

A single-blind randomized prospective cohort study was implemented. Patients consenting for orthognathic surgery at Thomas Jefferson University from January 2022 to October 2024 were screened. American Society of Anesthesiologists physical status I to III individuals aged ≥14 years were included. Exclusion criteria were revision surgery, recreational drug use, opioid prescription within 2 years, and chronic pain.

The predictor variable was anesthetic adjunct. Subjects were randomized to receive DEX or no DEX (control).

The primary outcome variable was 24-hour postoperative opioid consumption, which was calculated as morphine milligram equivalents (MME). Postoperative pain was assessed using a visual analog scale (VAS) at 6 hours and upon patient-controlled analgesia (PCA) discontinuation at 7:00 am the following day (VASPCA). The ratio of PCA that attempts to bolus deliveries was calculated.

Covariates included age, sex, body mass index (BMI), and operative duration.

Descriptive statistics were calculated. Shapiro-Wilk test was used to assess sample normality. Relationships between continuous variables and DEX were studied using t test or Wilcoxon rank-sum test; χ² test was used for the categorical covariate. Significance was P < .05.

Of 66 enrollees, 50 (75.8%) subjects completed the trial (25 DEX, 25 no DEX). The mean (SD) ages for the no DEX and DEX group cohorts were 35.9 (13.5) and 41.3 (13.6), respectively (P = .2). There were no statistically significant differences in the distribution of covariates between the 2 study groups. Median (interquartile range (IQR)) morphine milligram equivalents consumption was 16.4 (15.4) and 14.8 (12.4) for no DEX and DEX groups, respectively (P = .9). No difference in pain scores was observed at 6 hours (P = .1). Median (interquartile range) VASPCA scores were 5(1) and 4(2) for no DEX and DEX cohorts, respectively (P < .01). Median ratios of PCA that attempts to boluses administered (1.23) were identical between cohorts (P = .9).

The findings suggest that opioid consumption following orthognathic surgery was not associated with dexmedetomidine administration.