Neostigmine injected 5 minutes after low-dose rocuronium accelerates the recovery of neuromuscular function

To determine whether neostigmine 5 minutes after 0.4 mg/kg rocuronium accelerates reversal. Prospective, randomized, comparative open-label study. Operating room. 60 ASA physical status I and II patients, aged 18 to 65 years. Patients received 0.4 mg/kg rocuronium during nitrous oxide (N 2 O)-propofol-opioid anesthesia. Reversal of neuromuscular blockade was achieved with neostigmine, either at 0.03 mg/kg or 0.05 mg/kg intravenously (IV), together with glycopyrrolate administered 5 minutes after relaxant and compared with spontaneous recovery. Onset, depth, and duration of neuromuscular block, as well as recovery of train-of-four (TOF) to 0.8 and 0.9 were evaluated. Times to achieve TOF ratios of 0.8 and 0.9 were significantly shorter when 0.03 mg/kg or 0.05 mg/kg neostigmine was administered 5 minutes after administration of rocuronium (20.2 ± 5 min and 22.6 ± 5.9 min or 17.8 ± 4.8 min and 19.4 ± 5.1 min, respectively) compared with controls (36.2 ± 8.5 min and 39.0 ± 8.7 min; P < 0.01). Duration to spontaneous T1 25% recovery after rocuronium was 15.5 ± 6.5 min versus 9.3 ± 2.3 min and 7.7 ± 1.6 min in the treatment groups ( P < 0.01). Recovery index (T1 from 25% to 75%) was significantly shorter after neostigmine (7.1 ± 2.4 min and 5.7 ± 4.0 min) versus controls (13.3 ± 8.3 min; P < 0.01). Speed of reversal did not differ significantly between IV neostigmine doses of 0.03 mg/kg or 0.05 mg/kg. Neostigmine accelerates recovery when administered 5 minutes after injection of IV rocuronium 0.4 mg/kg.