Comparative potentiating effects of remimazolam, propofol and sevoflurane on rocuronium-induced neuromuscular block: a randomized controlled trial.

BACKGROUND

Remimazolam is a new type of ultra-short-acting benzodiazepine. The aim of this study was to investigate the effects of remimazolam, propofol and sevoflurane anesthesia on rocuronium-induced neuromuscular block.

METHODS

Ninety-nine consenting patients were randomly assigned to a remimazolam group (R-group), sevoflurane group (S-group), or propofol group (P-group). Train-of-four (TOF) responses evoked on the abductor digiti minimi muscle to ulnar nerve stimulation following bolus administration of 0.9-mg/kg rocuronium were monitored with electromyography-based neuromuscular monitor. The primary outcomes were times from administration of rocuronium to first reappearance of post-tetanic count (PTC). Free plasma concentrations of rocuronium were concurrently measured at these events.

RESULTS

Ninety patients were analyzed. No significant differences were seen in time to first PTC among the three groups. Mean (± standard deviation) and median (inter-quartile range) times for the reappearance of TOF counts 1 and 2 were significantly prolonged in S-group [50.7 ± 13.9 min, P = 0.043 and 61.6 (54.3-78.0) min, P = 0.020, respectively], when compared with P-group [42.6 ± 10.3 min and 52.9 (45.4-58.8) min, respectively]. However, no significant differences were seen between S-group and R-group. Median (inter-quartile range) free plasma concentration of rocuronium measured at first PTC was significantly lower in R-group [1255 (1126-1717) ng/mL] than in P-group [1717 (1592-1961) ng/mL, P = 0.031].

CONCLUSIONS

These results suggest that the potentiating effects of remimazolam on rocuronium-induced neuromuscular block are weaker than those of sevoflurane and similar to those of propofol.