Rocuronium attenuates oculocardiac reflex during squint surgery in children anesthetized with halothane and nitrous oxide.
BACKGROUND
The oculocardiac reflex (OCR) may be activated during squint surgery. The aim of this study was to test whether rocuronium 0.4 mg kg(-1) could reduce the frequency of OCR, and also whether a single dose of succinylcholine 1 mg kg(-1) could affect the frequency of OCR during anesthesia with halothane in a nitrous oxide/oxygen mixture.


METHODS
A total of 161 ASA I children, 3-10 years old, undergoing elective surgery of the medial rectus muscle (MRM) were randomly assigned to three groups. Group R (n = 51), received 0.4 mg kg(-1) of rocuronium intravenously before endotracheal intubation. Group S (n = 58) received 1 mg kg(-1) of succinylcholine. Group C (controls, n = 52) received no relaxant. Oculocardiac reflex was defined as a reduction in heart rate (HR) > or = 15% and/or the appearance of any other arrhythmias, during manipulation of the MRM. Analysis of variance (anova), chi-squared, Kruskal-Wallis, and Student's t-tests were used for statistical analysis; P< 0.05 was considered statistically significant.


RESULTS
In group R, OCR occurred in 15/51 (29%) of children, in group S in 31/58 (53%), and in group C in 23/52 (44%) (chi2 = 6.46, P = 0.049). In group R, the incidence of arrhythmias such as nodal rhythms, supraventricular and ventricular premature beats was 6%, compared with 22% in group S and 19% in group C (chi2 = 6.01, P = 0.040). However, there was no reduction in the occurrence of bradycardia (chi2 = 0.16, P = 0.924).


CONCLUSIONS
Rocuronium reduced the frequency of OCR, mainly by reducing the incidence of supraventricular and ventricular premature beats.
Karanovic
N
N
Department of Anesthesiology and Intensive Care, University Hospital Split, Split, Croatia.
Jukic
M
M
Carev
M
M
Kardum
G
G
Dogas
Z
Z
D000732:Androstanols / Q000627:therapeutic use*; D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D004562:Electrocardiography / Q000187:drug effects; D005260:Female; D006221:Halothane; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007431:Intraoperative Complications / Q000139:chemically induced / Q000453:epidemiology / Q000503:physiopathology / Q000517:prevention & control*; D008297:Male; D009467:Neuromuscular Depolarizing Agents / Q000494:pharmacology; D003473:Neuromuscular Nondepolarizing Agents / Q000627:therapeutic use*; D009609:Nitrous Oxide; D009801:Oculomotor Muscles / Q000601:surgery; D013508:Ophthalmologic Surgical Procedures; D012024:Reflex, Oculocardiac / Q000187:drug effects*; D000077123:Rocuronium; D013285:Strabismus / Q000601:surgery*; D013390:Succinylcholine / Q000494:pharmacology
D000732:Androstanols; D018685:Anesthetics, Inhalation; D009467:Neuromuscular Depolarizing Agents; D003473:Neuromuscular Nondepolarizing Agents; D013390:Succinylcholine; D009609:Nitrous Oxide; D006221:Halothane; D000077123:Rocuronium