The Effect of Alfentanil on Emergence Delirium Following General Anesthesia in Children: A Randomized Clinical Trial

BACKGROUND: Emergence delirium can occur after general anesthesia in children. An intravenous infusion of alfentanil may reduce the incidence or severity of emergence delirium after sevoflurane anesthesia. OBJECTIVE: The study aimed to investigate the effects of alfentanil intravenous infusion on emergence delirium and other perioperative complications. METHOD: This was a single-center, randomized, placebo-controlled, double-blind clinical trial. A total of 172 children undergoing ambulatory dental treatment were randomized into three groups. Alfentanil group Alf2 received 0.2 μg/kg/min of alfentanil for continuous infusion, alfentanil group Alf4 received 0.4 μg/kg/min alfentanil, and the saline group (group Sal) received a continuous infusion of normal saline, with the same volume as the two other groups, as a placebo. The incidence of emergence delirium (assessed by the Paediatric Anaesthesia Emergence Delirium [PAED] scale), hemodynamic parameters, and recovery characteristics were recorded during the recovery period. The Aono scale was also used to assess for emergence delirium. A WeChat applet was designed to facilitate a caregiver teleconsultation and to provide feedback on postoperative nausea and vomiting and any other complications after discharge. RESULTS: The incidence of emergence delirium in group Alf2 (22.9%) and group Alf4 (21.1%) was significantly lower than that observed in the Sal group (48.3%). The PAED scores in group Alf2 (6.4 ± 3.5) and group Alf4 (5.8 ± 3.8) were significantly lower than those for group Sal (9.6 ± 5.1) (p < 0.01). Ten children in the Alf4 group needed manual ventilatory assistance to maintain end-tidal carbon dioxide (ETCO(2)) < 55 mm; children in group Alf2 did not. There was no significant difference between the discharge time of groups Alf2 and Sal (31.2 ± 4.64 vs 30.5 ± 2.82 min; 0.659 [95% confidence interval {CI} −1.052 to 2.369], p = 0.643); the time to discharge of group Alf4 (35.16 ± 3.97 min) was significantly longer than that of groups Alf2 and Sal (p < 0.01). The incidence of nausea and vomiting was similar in the three groups. No other clinically relevant adverse events were observed. CONCLUSIONS: Intravenous infusion of 0.2 μg/kg/min and 0.4 μg/kg/min alfentanil decreased the incidence of emergence delirium in the post-anesthesia care unit. The 0.2 μg/kg/min dose of alfentanil resulted in less respiratory depression and discharge delay than the 0.4 μg/kg/min alfentanil dose. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2100043320) SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40272-022-00510-5.