Influence of age and gender on the pharmacodynamic parameters of rocuronium during total intravenous anesthesia.

AIMS To compare the pharmacodynamics of 0.6 mg kg(-1) rocuronium in young and older patients of both genders during total intravenous anesthesia. METHODS Following local ethics committee approval and informed consent, patients scheduled for surgery under total intravenous anesthesia (propofol/sufentanil) were divided into 4 study groups: 37 males aged 20-40, 40 males aged 60-75 yrs, 43 females aged 20-40 and 38 females aged 60-75 yrs. Neuromuscular block following rocuronium (0.6 mg kg(-1)) was monitored: train-of-four [TOF] stimulation of the ulnar nerve at 15-s intervals, EMG of the adductor pollicis muscle. The onset time (from application of rocuronium to maximum depression of T(1)), clinical duration (from application to 25% recovery of T(1)), and time to full spontaneous recovery (from application to TOF-ratio ≥ 0.9) were determined for each patient. The Kruskal-Wallis test was used to compare differences between groups; P<0.05 was considered statistically significant. RESULTS The onset time (median [interquartile range]) in the respective groups was 90 [80-110](BCD), 135 [116-165](AC), 75 [60-90](ABD), and 120 [90-146](AC) seconds. The clinical duration was 30 [25-42](BCD), 58 [53-67](AD), 50 [40-65](AD), and 85 [70-90](ABC) min. Interval to full spontaneous recovery was 59 [51-67](BCD), 102 [75-106](A), 76 [66-91](AD), and 128 [94-137](AC) min. ((A)P<0.05 vs. young males, (B)P<0.05 vs. elderly males, (C)P<0.05 vs. young females, (D)P<0.05 vs. elderly females). CONCLUSION Females and older patients were more sensitive to rocuronium.