Supplemental Regional Block Anesthesia Reduces Opioid Utilization Following Free Flap Reconstruction of the Oral Cavity: A Prospective, Randomized Clinical Trial.

[PURPOSE] Regional anesthesia has been shown to effectively manage acute pain and reduce opioid utilization in the early postoperative period following colorectal, orthopedic, and thoracic surgeries. The same effect, however, has not been demonstrated in major head and neck surgery. The purpose of this study is to determine whether supplemental regional anesthesia reduces opioid utilization following microvascular free flap reconstruction of the oral cavity.

[METHODS] A prospective, randomized clinical trial was conducted for patients undergoing oral cavity reconstruction using microvascular free tissue transfer between January 2020 and March 2022. The predictor variable was a regional anesthetic nerve block, delivered preoperatively, at the flap donor site. The primary and secondary outcomes were opioid utilization, measured in oral morphine equivalent (OME), from postoperative day 1 to 5, and hospital length of stay (LOS), respectively. Covariates included age, sex, tobacco and alcohol history, prior radiation therapy, pathology, oral site, flap type, tracheostomy, and neck dissection. Student's t test, χ test, and linear regression models were computed using correlations with 95% confidence intervals (CIs). For all statistical tests, P values of <.05 were regarded as statistically significant.

[RESULTS] Ninety-eight participants completed the study. The mean age was 56 years with 55% male. Forty-eight patients received a presurgical regional anesthesia block, and 50 patients served as control subjects. Bivariate analysis demonstrated an even distribution of all study variables. Total OME utilization was significantly less in the treatment group compared to the control group, (166.32 vs 118.43 OME; 95% CI, 1.32 to 94.45; P = .04). The LOS was comparable (6.60 vs 6.48 days; 95% CI, -0.53 to 0.77; P = .71). Tobacco use had a positive effect (B = 0.28; 95% CI, 21.63 to 115.31; P = .005) while the block had a negative effect with total OME, (B = -0.19; 95% CI, -90.39 to -0.59; P = .047). The extent of the neck dissection (B = 0.207; 95% CI, 0.026 to 1.403; P = .042) was a positive predictor for LOS. Overall, there were no adverse events associated with the regional block throughout the study period.

[CONCLUSIONS] Supplemental regional anesthesia is safe and associated with reduced opioid utilization in patients undergoing vascularized free flap reconstruction of composite oral cavity defects and does not prolong the length of hospitalization.