Efficiency of the TOF-Cuff™ for the evaluation of rocuronium-induced neuromuscular block and its reversal with sugammadex: a comparative study vs. acceleromyography.

PURPOSE: The aim of this study was to compare TOF-Cuff™ (TOF-C) and TOF-Watch™ (TOF-W) data following rocuronium-induced neuromuscular block and its reversal with sugammadex. METHODS: Twenty elderly patients aged 68-82 years scheduled for surgery under general anesthesia were enrolled in this study. After induction of anesthesia, neuromuscular block resulting from administration of 0.6 mg/kg rocuronium was concurrently evaluated using TOF-C and TOF-W. The onset of neuromuscular block and duration until the first twitch response following post-tetanic count (PTC) and 2 Hz train-of-four (TOF) stimulation reappeared were evaluated. When the response to the TOF stimulus was detected with both monitors, additional doses of rocuronium were administered to maintain the neuromuscular block. After surgery, 2 mg/kg sugammadex was administered when 1-2 TOF twitches were observed with the TOF-W and the time required for facilitated recovery to a TOF ratio of > 0.9 was assessed. RESULTS: Regression analyses revealed no statistically significant differences in the mean [SD] onset of rocuronium-induced neuromuscular block [127.8 (27.2) s, 123.5 (30.5) s], time to recovery of the first PTC twitch [23.9 (8.0) min, 25.4 (8.6) min], time to recovery of the first twitch with TOF stimulation [37.2 (8.8) min, 38.9 (11.1) min] and time to adequate reversal with sugammadex [139.2 (30.6) s, 151.8 (31.5) s] between TOF-C and TOF-W, respectively. Bland-Altman analyses also showed acceptable ranges of the biases and limits of agreement between the two methods. CONCLUSIONS: TOF-C may be clinically applicable for the evaluation of both the depth of neuromuscular block and restoration of neuromuscular function.

Effects of cardiac output on the onset of rocuronium-induced neuromuscular block in elderly patients.

PURPOSE: The 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. METHODS: Forty 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. RESULTS: The 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]. CONCLUSIONS: In the elderly, CO influences the onset of action of rocuronium.