Routine administration of neostigmine after recovery of spontaneous breathing versus neuromuscular monitor-guided administration of neostigmine in pediatric patients: a parallel, randomized, controlled study
Authors: Yang Lei , Hu Na , Chang Hong , Yang Di , Zuo Yunxia 
Published: January 2023

Abstract
Background
Neostigmine used to reverse the muscle relaxants should be guided by neuromuscular monitoring, as the degree of spontaneous pre-reversal recovery is the key to success to reverse the neuromuscular block. But neuromuscular monitoring is not always available for some patients during anesthesia and, in consequence, we need to use other clinical judgment to guide the use of neostigmine to reverse the neuromuscular block. In this trial, we aimed to evaluate the incidence of residual neuromuscular blockade (rNMB) in pediatric patients with routine use of neostigmine after recovery of spontaneous breathing compared with the patients with the use of neostigmine guided by neuromuscular monitoring.

Methods
A parallel, randomized, controlled noninferiority study was conducted. We enrolled aged 3 months to 12 years old patients who underwent inguinal hernia repair under general anesthesia. The enrolled patients were randomly divided into experimental and control groups. After surgery, children in the experimental group were given 0.02 mg/kg neostigmine after recovery of spontaneous breathing. Children in the control group were given 0.02 mg/kg neostigmine when the train-of-four (TOF) ratio was between 0.4 and 0.9. However, no neostigmine was administered if the TOF ratio was higher than 0.9. The primary outcome was the incidence of rNMB after extubation (TOF ratio < 0.9). Secondary outcomes included the incidence of neostigmine-induced muscle paralysis, end of surgery – extubation interval, end of surgery – exit OR interval, the length of stay in the PACU, the incidence of hypoxia in the PACU, the number of children who required assisted ventilation during the PACU stay, and neostigmine-related adverse events.

Results
A total of 120 children were included in this study, with 60 in the experimental group and 60 in the control group. There was no significant difference in the incidence of rNMB after extubation between the groups (45/60 vs 44/60, RR 1.02 [95% CI, 0.83 to 1.26], p = 0.84). There was no neostigmine-induced muscle paralysis in either group. Adverse events were similar occurred in both groups. However, time from end of the surgery to leaving the operating room was earlier in the experimental group than in the control group (13.6 ± 5.2 vs 15.7 ± 5.6 min, MD −2.10 min [95% CI, −3.70 to −0.50], p = 0.04). The risk ratio of the incidence of TOF ratio < 0.3 for the experimental group was 31.12 (95%CI, 1.89 to 512.61) compared with the control group (12/60 vs 0/60, p = 0.00) in exploratory analysis.

Conclusions
Recovery of spontaneous breathing could be used as a substitute of neuromuscular monitoring to guide neostigmine use in pediatric patients following minor surgeries. However, care should be taken for the residual neuromuscular block.

Trial registration
Chinese Clinical Trial Registry ChiCTR-IOR-17012890. Registered on 5 October 2017