Association of heart rate and oculocardiac reflex (OCR) during strabismus surgery in children.

Abstract

Objective: To determine the relationship between the baseline heart rate and the occurrence of the oculocardiac reflex in pediatric strabismus surgery using horizontal extraocular muscles. Study Design: Observational study that was designed as a retrospective study. Setting: Mughal Eye Hospital, Lahore, Pakistan. Period: January-July 2024. Methods: Fifty children aged 3-12 years old who had elective surgery on strabismus (either esotropia or exotropia) were included. The baseline heart rate was used to classify patients as low (70-90bpm) and high (91-120bpm). All the surgeries were done under a standardised general anesthesia with intraoperative follow-up. The OCR was characterized as a 20 percent or more decrease in heart rate at baseline with extraocular muscle traction. Data were also analyzed with SPSS version 26, and associations were determined with the Chi-square test, and p was taken as significant (p < 0.05). Results: The mean age of participants was 7.6 ± 2.4 years, and the overall incidence of OCR was 58%. OCR occurred in 78.6% of patients with a low baseline heart rate and 31.8% of those with a high baseline heart rate, showing a statistically significant association (p = 0.001). OCR was more frequent during medial rectus surgery (35.7%) than lateral rectus (22.7%), though this difference was not statistically significant (p = 0.320). All OCR episodes were transient and managed successfully with cessation of traction and deepening of anesthesia. Conclusion: Children with lower baseline heart rates are significantly more prone to developing the oculocardiac reflex during strabismus surgery. Preoperative assessment of heart rate can thus serve as a simple yet valuable predictor for identifying high-risk patients and enhancing intraoperative preparedness.