Comparison of effects of sevoflurane on neuromuscular blockade induced by rocuronium in patients with and without diabetes mellitus

Objective To compare the effects of sevofturane on neuromuscular block induced by rocuronium in the patients with or without diabetes mellitus. Methods Thirty diabetic and 30 non-diabetic ASA Ⅱ patients aged 45-64 yr scheduled for elective middle or lower abdominal surgery were studied. Both diabetic and non-diabetic patients were randomly assigned to one of 2 groups (n = 15 each): propofol group (group P) and sevoflurane group (group S). All patients were anesthetized with midazolam, propofol and fentanyl. After loss of consciousness tracheal intubation was performed after rocuronium 0.6 mg/kg and anesthesia was maintained with iv propofol infusion in group P. In group S tracheal intubation was performed under topical anesthesia with 1% amethacaine injected through cricotbyroid membrane. Anesthesia was maintained with sevoflurane inhalation (end-tidal concentration 1.71 %). Rocuronium 0.6 mg/kg was given iv at 10 min after inhalation of sevoflurane was started. Neuromuscular function was assessed by accelerograpby (TOF-Watch SX, Orgnnon, Holland). TOF stimulation of ulnar nerve was used. The onset time, duration of action and recovery index (for T1 to return from 25% to 75% of the control twitch) were recorded. The T1/T0 and TOF (T4/T1) ratios were recorded at 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110 and 120 min after a single bolus of rocuronium. Results There was no significant difference in onset time and duration of action between diabetic and non-diabetic patients in both propofol and sevoflurane groups. The recovery index was significantly higher in diabetic patients than in non-diabetic patients in group S. The recovery index was significantly higher in group S than in group P in diabetic patients. The ratios of T1/T0 and TOF were significantly lower in group S than in group P in diabetic patients during 60-120 min after a single bolus of rocuronium. The TOF ratio was significantly lower in diabetic patients than in non-diabetic patients in group S during 80-120 min after a single bolus of rocuronium. Conclusion The effect of sevoflurane on rocuronium-induced neuromuscular block is enhanced in diabetic patients compared with non-diabetic patients. Key words: Androstanols; Diabetes mellitus; Neuromuscular blockade; Sevoflurane