Effects of Intranasal dexmedetomidine and esketamine for premedication on postoperative pain after tonsillectomy and adenoidectomy in children: a randomized clinical trial.

Background: Postoperative acute pain is a common issue in children after surgery. Our study aimed to investigate whether preoperative use of a dexmedetomidine-esketamine combination could reduce postoperative pain in children undergoing tonsillectomy and adenoidectomy and reduce side effects, such as bradycardia, hypotension or emergence delirium.

Methods: In this double-blind, randomised controlled clinical trial, 180 children were randomly assigned to 3 groups. 30 min before surgery, the control group received 0.9% saline intranasally (Group C), the dexmedetomidine group received intranasal dexmedetomidine at 2.0 μg·kg^-1 (Group D), and the combination group received intranasal dexmedetomidine at 1.0 μg·kg^-1 and esketamine at 0.6 mg·kg^-1 (Group DS). The primary outcome was the area under the curve (AUC) of the pain score within 24 h after surgery. Secondary outcomes included the incidence of emergence delirium (ED), pain scores after hospital discharge, and incidence of perioperative adverse events.

Results: A total of 173 children completed the study. The AUC of the pain score at rest within 24 h after surgery was 37.25 (20.25-51.75) in Group C, which was higher than those in Groups D (19.25 [12.50-39.13], P < 0.001) and DS (9.50 [9.00-16.25], P < 0.001). Compared with the control group, the DS group had a lower incidence of ED (12.3% vs. 44.8%, P = 0.001). Heart rates (HRs) in groups DS (P < 0.001) and C (P < 0.001) were higher than those in the dexmedetomidine group at all time points. No serious adverse events occurred.

Conclusions: Intranasal dexmedetomidine combined with esketamine for premedication was associated with reduced postoperative pain in children. It can also prevent ED and had fewer side effects.