Inhibitory effect of low-dose esketamine on cough induced by sufentanil during the induction of anesthesia and postoperative impact on mental health status: a prospective, single-center, randomized controlled trial.

Background: Intravenous administration of sufentanil during anesthesia induction induces cough (SIC), sometimes triggers a severe reaction. We wanted to investigate the inhibitory effect of low-dose esketamine on cough induced by sufentanil during the induction of general anesthesia, as well as its postoperative impact on mental status (MMSE score, RSS, and VAS-A).

Methods: A total of 256 adult patients were randomly allocated to receive either esketamine (Group EK) or normal saline (Group C). One minute before the administration of sufentanil, Group EK and Group C were injected with esketamine (0.05 mg/kg, diluted with normal saline to 3 ml) and normal saline (3 ml), respectively. The primary outcomes were the incidence (the basis of the presence or absence of cough) and severity (the frequency of cough episodes) of cough within 2 min after sufentanil injection.The secondary outcomes included hemodynamic variables (MAP, HR, and SPi), mental status (MMSE score, RSS, and VAS-A) and postoperative events (time to awareness, duration of orientation recovery and degree of satisfaction with anesthesia).

Results: A total of 236 adult patients were randomized into two groups (n = 236): Group EK (n = 118) and Group C (n = 118). The incidence of cough in Group EK (21.2%) was significantly lower than that in Group C (40.7%) (P < 0.05). The incidence rates for each grade were as follows: 9.3% and 16.9% for Grade 2, and 0% and 4.2% for Grade 3, respectively.The differences had statistical senses.The MAP and HR at T4 (during tracheal intubation) and T5 (1 min post-intubation) were significantly lower in Group EK (P < 0.05). There were no significant differences in MMSE score, RSS, and VAS-A, time to awareness, duration of orientation recovery or satisfaction with anesthesia.

Conclusion: Pretreatment with low-dose esketamine can reduce the incidence and severity of cough induced by sufentanil and maintain hemodynamic stability during anesthesia induction without increasing mental status (MMSE score, RSS, and VAS-A).

Trial Registration: Chinese Clinical Trial Registry (ChiCTR2400084940, date of registration: 05/28/2024).