Effect of competitive myoneural blockade and fentanyl on muscle fasciculation caused by suxamethonium in children.

The effects of tubocurarine 0.06 mg kg-1, alcuronium 0.03 mg kg-1, pancuronium 0.01 mg kg-1, and fentanyl 1 or 2 micrograms kg-1 on the muscle fasciculations associated with suxamethonium were studied in 171 children undergoing otolaryngological surgery. The mean fasciculation index in all pretreatment groups was significantly smaller than in the control group. The most effective pretreatment was fentanyl 2 micrograms kg-1 followed, in order, by alcuronium, fentanyl 1 microgram kg-1, tubocurarine and pancuronium. The rate of the onset of the fasciculations after the injection of suxamethonium ranged from 8 s after pancuronium to 20 s after tubocurarine. There was evidence of respiratory depression in the children receiving fentanyl 2 micrograms kg-1 if the duration of anaesthesia was less than 30 min.