Rocuronium administration in children during isoflurane anesthesia: neuromuscular effects.
BACKGROUND
The time-course of the effect of rocuronium during isoflurane anesthesia in children has rarely been 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 micrograms/kg of rocuronium. The first response to the control height (T1:T0) was fitted to time in order to obtain times to onset of action (TOA) including time to 90 (B90) and 99.9% (B100) of relaxation and to spontaneous recovery of 10 (T10), 25 (T25), 50 (T50), 75 (T75), and 90% (T90) of neuromuscular function (NMF). Each time was compared among groups. 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 micrograms/kg were longer (p < 0.05) than children receiving 400 micrograms/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 stronger in males than females.


CONCLUSIONS
Maximal relaxation was reached in all children receiving 600 or 800 micrograms/kg of rocuronium. The TSRNMF were mainly related to the weight of the children, and gender affected each relationship. Widely variable responses were observed with all three doses.
Villegas-Sánchez
F
F
Departamento de Anestesia, Terapia Respiratoria y Clínica del Dolor, Hospital Infantil de México-Federico Gómez, México, D.F., Mexico.
Charles-Torres
J D
JD
Moyao-García
D
D
Nava-Ocampo
A A
AA
Velázquez-Armenta
E Y
EY
D000293:Adolescent; D000732:Androstanols / Q000008:administration & dosage / Q000494:pharmacology*; D018685:Anesthetics, Inhalation; D002648:Child; D002675:Child, Preschool; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007530:Isoflurane; D016014:Linear Models; D008297:Male; D019148:Neuromuscular Blockade; D003473:Neuromuscular Nondepolarizing Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000077123:Rocuronium; D014459:Ulnar Nerve / Q000187:drug effects / Q000502:physiology
D000732:Androstanols; D018685:Anesthetics, Inhalation; D003473:Neuromuscular Nondepolarizing Agents; D007530:Isoflurane; D000077123:Rocuronium