Factors Influencing Bradycardia during Spinal Anesthesia in Obstetric Patients Undergoing Cesarean Section
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Background: Spinal anaesthesia is widely used for caesarean delivery, but sympathetic blockade can produce hypotension and maternal bradycardia. Recognition of associated factors is important for timely intraoperative monitoring and management. Objective: To determine the frequency, clinical characteristics, and factors associated with bradycardia during spinal anaesthesia for caesarean section. Methods: A hospital-based observational study included 138 women aged 18–40 years undergoing elective or emergency caesarean delivery under spinal anaesthesia at Maqsood Medical Complex Hospital and Hayatabad Medical Complex, Peshawar. Bradycardia was defined as heart rate <60 beats/min, while hypotension was defined as a >30% reduction in systolic blood pressure from baseline. Results: Bradycardia occurred in 26/138 patients (18.8%; 95% CI 13.2–26.2%) and hypotension in 38/138 (27.5%). Most bradycardic episodes occurred 6–15 minutes after spinal anaesthesia. Atropine was administered in 15/26 cases (57.7%). High sensory block level was associated with bradycardia, χ²=9.84, p=.043, and hypotension was also associated with bradycardia, χ²=5.31, p=.021. In exploratory multivariable analysis, a high block level (T4–T6 versus ≥T7) was associated with greater odds of bradycardia (OR 2.31, 95% CI 1.08–5.21; p=.031), as was hypotension (OR 3.44, 95% CI 1.37–8.62; p=.009). Conclusion: Approximately one in five women developed bradycardia. Higher sensory block and concurrent hypotension were the principal factors associated with bradycardia in this cohort.
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