Resistance to vecuronium in burned children

We compared the time-course of action of vecuronium in 16 burned children undergoing excision and autograft surgery with that of ten unburned children. Standardized anaesthesia was induced with thiopentone 4-6 mg kg-1 and fentanyl 1 microgram.kg-1 and maintained with endtidal 1-1.5% isoflurane in N2O/O2. Neuromuscular responses were monitored by acceleromyography (TOF-Guard, Organon Teknika/Biometer) with supramaximal train-of-four (TOF) stimuli delivered every 15s. Vecuronium 0.1 mg kg-1 was administered intravenously. Onset was recorded as the time, in seconds, between the initial bolus of vecuronium and a decline in the first twitch of TOF (T1) to 5% of control. The times for the recovery of T1-25%, 50% and 75% of control, recovery index and the recovery of TOF 25% and 50% were recorded. Onset of action was found slower in burned patients (189 +/- 70 s) than in control (98 +/- 20 s) (P < 0.01). Recovery times of T1(25), T1(50), T1(75), TOF25 and TOF50 were significantly shorter in burned patients indicative of decreased sensitivity to vecuronium (P < 0.01).