Administering dexmedetomidine intraoperatively decreased the incidence of chronic incision pain and acute pain scores in patients who underwent frontotemporal brain tumor resection, according to results from a secondary analysis of a randomized, double-blind, placebo-controlled trial published in Anesthesia & Analgesia.
Researchers evaluated 252 patients enrolled from January to December 2021 in a study originally designed to determine the effect of dexmedetomidine on delirium after neurosurgery. The researchers made a prospective follow-up visit to patients 3 months after surgery to collect data for a secondary analysis to determine the effect of dexmedetomidine on chronic incision pain following craniotomy.
Patients randomly assigned to the dexmedetomidine group (n=128) received a 0.6-μg per kg bolus of dexmedetomidine 10 minutes after induction of anesthesia and endotracheal intubation, then a 0.4-μg per kg per hour maintenance infusion until dural closure. Patients randomly assigned to the placebo group (n=124) received comparable amounts of normal saline. Dexmedetomidine and saline were administered with a 50-mL syringe.
The primary outcome of the study was the incidence of incision pain 3 months after craniotomy as determined by numerical rating scale scores and defined as any score greater than 0. Secondary outcomes included postoperative acute pain scores, sleep quality, and responses on the Short-Form McGill Pain Questionnaire (SF-MPQ-2) 3 months after craniotomy.
Postoperatively, the incidence of chronic incision pain was 23.4% in the dexmedetomidine group and 42.7% in the placebo group (risk ratio, 0.55; 95% CI, 0.38-0.80; P =.001). In both groups, chronic incision pain was mild. During the first 3 days after surgery, however, patients in the dexmedetomidine group had lower acute pain severity scores during movement (all P <.01 after adjustment), lower SF-MPQ-2 total sensory scores (P =.01), and lower neuropathic pain descriptor scores (P =.023) compared with the placebo group. The difference in pain numerical rating scale scores was statistically significant but of little clinical significance. Sleep quality was similar in both groups.
Study limitations included an inability to do a preplanned power estimate for the sample size because of the secondary nature of the analysis. Other limitations were potential differences in analgesia of the scalp nerve block due to differences in surgical sites and incision sizes; and the use of concomitant full analgesia, which led to low incision pain scores.
“Intraoperative dexmedetomidine infusion reduced the incidence of chronic incisional pan by about half, as well as the acute pain score.” the authors concluded. They added, “Intraoperative side effects, postoperative complication, and PACU [postanesthetic care unit] stay length did not differ between groups.”
Zeng M, Xu X, Li R, et al. Dexmedetomidine prevents chronic incisional pain after brain tumor resection: a secondary analysis of the randomized control trial. Anesth Analg. Published online June 12, 2023. doi:10.1213/ANE.0000000000006563