Emergence agitation (EA) is common after orthognathic surgery and poses a significant threat to clinical safety. The aim of our study was to investigate the efficacy and safety of a subanesthetic dose of esketamine in preventing EA following bimaxillary orthognathic surgery.

A total of 272 patients underwent bimaxillary orthognathic surgery were randomly allocated into two groups. In the esketamine group, 0.25 mg/kg esketamine was infused at the end of the surgery, whereas in the control group, placebo (normal saline) was infused. The primary endpoint was the incidence of EA (assessed with the Richmond Agitation Sedation Scale; defined as the score ≥ +2).

All included patients were analyzed according to the intention-to-treat principle. The incidence of EA was significantly lower in the esketamine group than in the control group (19.1%vs 33.1%, P = 0.013). Meanwhile, patients in the esketamine group experienced a prolonged emergence time (45 [30,65]min vs 30 [20,59]min, P < 0.001) and extubation time (75 [50,119]min vs. 60 [40,99]min, P < 0.039). Moreover, subjective sleep quality on the night of surgery and postoperative anxiety and depression within the first 24 h after surgery did not differ significantly between groups.

A subanesthetic dose of esketamine administered at the end of procedure was effective in preventing EA after bimaxillary orthognathic surgery managed with a delayed extubation protocol. Given the prolonged emergence and extubation time, its use should be further evaluated for other types of surgeries that require rapid awakening and early extubation.