Effect of low-dose remifentanil infusion on emergence agitation after general anaesthesia in patients undergoing intracranial surgery: study protocol of a randomised controlled trial.

Abstract

Emergence agitation (EA), defined as acute postoperative restlessness after general anaesthesia, is a common complication in the post-anaesthesia care unit (PACU). The reported incidence of EA is nearly 30% in neurosurgical surgery, which bears tremendous risks for neurosurgical patients. Although current evidence suggests that remifentanil may reduce EA risk in non-cardiac settings, its preventive efficacy in patients undergoing intracranial surgery remains unclear. In this single-centre, randomised, double-blind, parallel-group prospective clinical trial, patients scheduled for elective craniotomy will be screened to confirm their eligibility. After surgery under general anaesthesia, patients will be assigned to groups to receive either remifentanil or placebo infusion on admission to the PACU. The remifentanil group will be given remifentanil infusion at a dose of 0.1 µg/(kg×min), whereas the control group will be given the same volume of normal saline. The primary outcome is the effect of remifentanil on EA incidence during the emergence period. Secondary outcomes include the following: time to regain consciousness, extubation time, total PACU duration, extubation comfort score measured by the modified Minogue Scale, postoperative pain intensity assessed using a Numerical Rating Scale, awakening quality and postoperative delirium assessed by alertness and orientation score, and a 3-Minute Diagnostic Interview for Confusion Assessment Method. The study protocol (V.4.0, dated 14 August 2025, No. 2025-0954) has been approved by the Institutional Ethics Committee of the First Affiliated Hospital, Zhejiang University School of Medicine and complies with the Declaration of Helsinki and relevant regulations for research involving human participants. Findings will be disseminated through peer-reviewed publications and conference presentations. ChiCTR2500096691.