Rocuronium administration in children during isoflurane anesthesia: neuromuscular effects

ABSTRACT

Brockground. The time-course of the effect of rocuronium during isoflurane anesthesia in children rarely evaluated. Forty-five children, aged 2-14 years, ASA 1, undergoing elective surgery and receiving isoflurane anesthesia, were studied. Methods. Patients randomly received a dose of 400, 600, or 800 µg/kg of rocuronium. The first response to control height (T1:TO) was fitted to time in order to obtain times to onset of action (TOA) including time to 90 (b10) and 99.9 percent (B100) of relaxation and to spontaneous reconver of 10 (T10), 25 (t25), 50 (t75), and 90 percent (T90) of neuromuscular function (NMF). Each time was compared among group. Linear regression analysis between the TOA or the times to spontaneous recovery of NMF (TSRNMF) and age or weight were also performed. Results. The TOA were similar among the three groups while TSRNF in children receiving 600 or 800 µg/kg were longer (p< 0.05) than children receiving 400 µg/kg. The T10 and T25 were related to age (p= 0.05), whereas T10, T50, T75, and T90 were related to weight (p< 0.01). These relationships were stringer in males than females. Conclusions. Maximal relaxation was reached in all children receiving 600 or 800 µg/kg of rocuronium. The TSRNMF were mainly related to the weight of the children, and gender affected each relationship. Widely variable response were observed with all three doses