Kim_2004_Anesth.Analg_99_1080

We sought to determine whether tactile train-of-four (TOF) count can predict the efficacy of neostigmine administration for rocuronium-induced blockade during propofol or sevoflurane anesthesia, and to follow subsequent recovery until the TOF ratio reached 0.9. One-hundred-sixty patients, divided into eight equal groups, were randomly allocated to maintenance of anesthesia with propofol or sevoflurane. The tactile response of the adductor pollicis to TOF stimulation was evaluated on one arm, and the mechanomyographic response was recorded on the other. Neuromuscular block was induced with rocuronium 0.6 mg/kg and maintained with rocuronium to 15% of the control first twitch in TOF. Neostigmine 0.07 mg/kg was administered on reappearance of the first (Group I), second (Group II), third (Group III), or fourth (Group IV) tactile TOF response in each anesthesia. At this time, sevoflurane or the propofol dosage was reduced in each group (n = 20 in each group). The times from administration of neostigmine until the TOF ratio recovered to 0.7, 0.8, and 0.9 were recorded. The times [median (range)] to TOF ratio = 0.9 were 8.6 (4.7-18.9), 7.5 (3.4-9.8), 5.4 (1.6-8.6), and 4.7 (1.3-7.2) min in Groups I-IV during propofol anesthesia, respectively, and 28.6 (8.8-75.8), 22.6 (8.3-57.4), 15.6 (7.3-43.9), and 9.7 (5.1-26.4) min in corresponding groups during sevoflurane anesthesia, respectively (P < 0.0001). We recommend more than 2 TOF responses with propofol anesthesia and 4 TOF responses with sevoflurane anesthesia for adequate reversal within 10 and 15 min, respectively. The more tactile TOF responses present at the time of reversal achieved greater adequate recovery; however, tactile TOF responses are not a completely reliable predictor within a reasonable time period.