LAUSR

PurposeThe aim of this study was to elucidate the relationship between the onset of rocuronium-induced neuromuscular block and arterial pressure-based cardiac output (CO) in elderly patients.MethodsForty elderly patients aged 65–83 years were enrolled in this study. After induction of anesthesia, contractions of the adductor pollicis muscle to ulnar nerve train-of-four stimulation were acceleromyographically evaluated and 1 mg/kg rocuronium was administered following CO measurement. The correlation between onset of rocuronium action and CO was analyzed.ResultsThe mean [SD] CO reduced after induction of anesthesia from 5.1 [1.8] L/min to 3.8 [1.1] L/min. The onset time of rocuronium-induced neuromuscular block was 110.3 [23.9] s (range 60–165). There was a statistically significant inverse correlation between the onset time of rocuronium and CO [onset time (s) = − 13.2·CO + 159.7, R2 = 0.376].ConclusionsIn the elderly, CO influences the onset of action of rocuronium.