Half-dose neostigmine and low dose sugammadex as a reversal agent for vecuronium: a pilot randomized trial

The incidence of residual neuromuscular blockade after surgery is still high, and the traditional neuromuscular blocking agent neostigmine has many disadvantages. Sugammadex represents a novel class of neuromuscular blocking antagonist, exhibiting selectivity for rocuronium and vecuronium. But the reversal effect of half-dose neostigmine combined with half-dose or low-dose Sugammadex for vecuronium is unknown. To explore better antagonistic options, we designed this clinical trial and compared it with a single antagonist.

80 patients undergoing elective urinary surgery under general anesthesia were randomly assigned to four groups: Group N (standard full-dose neostigmine 0.05 mg/kg + atropine 0.02 mg/kg); Group HN + HS (half-dose neostigmine 0.025 mg/kg + atropine 0.01 mg/kg, followed 3 min later by sugammadex1.0 mg/kg); Group HN + LS (half-dose neostigmine 0.025 mg/kg + atropine 0.01 mg/kg, followed 3 min later by sugammadex0.5 mg/kg); Group S (normal saline, followed 3 min later by sugammadex2.0 mg/kg). The primary outcome was the time from the start of administration of antagonist to recovery of the T4/T1 ratio to 0.9. Secondary outcome was the prevalence of hypoxia, defined as SpO₂ < 90% for >10 s within 1 h after extubation.

Group S, Group HN + HS, and Group HN + LS reversed a threshold train-of-four count of two to a normalized train-of-four ratio of 0.9 or higher in all patients in 326.95 ± 23.21 s, 317.05 ± 55.04 s, and 361.68 ± 23.21 s (mean ± SD), respectively. There were no significant differences between the three groups. Whereas Group N produced a reversal in 592.32 ± 159.88 s (P < 0.001 vs Group S, Group HN + HS, and Group HN + LS). One patient (5.3%) in Group N experienced hypoxia.

A low-dose sugammadex (1.0 and 0.5 mg/kg) after half-dose reversal of neostigmine provides shorter recovery times compared to full-dose neostigmine reversal agent, and it has no statistically significant differences in recovery times compared with the standard dose of sugammadex (2.0 mg/kg) using our administration method.