Efficacy of low-dose nalmefene on recovery from general anaesthesia in adult patients: a multicentre randomised controlled study

OBJECTIVES: This randomised controlled trial aims to evaluate the impact of low-dose intravenous nalmefene on anaesthesia recovery in adult patients aged 18-65 undergoing surgery under general anaesthesia. DESIGN: This was a multicentre, randomised, double-blind trial with two parallel arms clinical study. SETTING: Four hospitals from China PARTICIPANTS: A total of 514 patients aged 18-65 who underwent elective orthopaedic, urologic and thoracic surgeries. INTERVENTIONS: On completion of skin suturing, the intervention group received a single intravenous dose of nalmefene (0.25 µg/kg). The control group received an equivalent volume of normal saline at the same time point. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the interval time between the end of anaesthesia and the Aldrete score ≥9 being achieved in the postanaesthesia care unit (PACU). The secondary endpoints included the time interval from the end of operation to extubation; Richmond Agitation Sedation Scale (RASS) score at extubation; the time at Montreal Cognitive Assessment Scale (MoCA) orientation score ≥5; visual analogue scale (VAS) score in PACU and 24 hours postoperatively. RESULTS: 514 patients were included in the Intention-to-Treat (ITT) analysis. The time interval between the end of anaesthesia and Aldrete score reached ≥9 in PACU was significantly shorter in the intervention group than in the control group (mean (SD) 24.8 (11.8) min vs 33.8 (12.5) min; 95% CI -8.8 (-10.8 to -6.7); p