الفهرس | Only 14 pages are availabe for public view |
Abstract Background: Strabismus correction in children is associated with high incidence of oculocardiac reflex (OCR). So, this study was designed to evaluate the effect of local application of lidocaine or ropivacaine on extraocular muscles on the incidence of OCR during strabismus surgery in children. Methods: This controlled randomized study was carried out on 30 children (3 - 14 years) of either sex, requiring correction of strabismus under general anesthesia. No premedications were given. Anesthesia was induced with thiopentone 3-5mg/kg and maintained with 65% N2O in O2 with addition of isoflurane 0.6-1%. Endotracheal intubation was facilitated with atracurium 0.5-0.6mg/kg and controlled ventilation was used. The patients were categorized into 3 groups of 10 patients each according to the drug applied locally on the extraocular muscle as follows: control group received saline (5ml), lidocaine group received 1mg/kg lidocaine 2% in 5ml saline and ropivacaine group received 1mg/kg ropivacaine 0.75% in 5ml saline. Patient’s heart rate (HR) and mean arterial pressure (MAP) were recorded after 5min from drug application just before muscle traction and after traction. The OCR was determined from changes in HR and MAP occurred after muscle traction. The OCR was considered positive if the decrease in HR occurred after traction was 20% or more from its value before traction. Also, cardiac rhythms other than bradycardia were recorded. Results: The incidence of OCR was 90% in control group, while, it showed significant decrease to 30% in lidocaine group and to 20% in ropivacaine group. Also, the incidence of other types of arrhythmias as supraventricular ectopics decreased significantly from 70% in control group to 30% in lidocaine group and to 10% in ropivacaine group. The HR decreased significantly in control group after muscle traction compared to lidocaine and ropivacaine groups. There was non significant change in MAP after muscle traction in all groups and systemic side effects of lidocaine or ropivacaine were not seen. Conclusion: Lidocaine and ropivacaine in a dose of 1mg/kg applied superficially to the exttraocular muscles can be used safely to reduce the incidence of OCR during strabismus surgery in children. |