An Observational Study on Arrhythmia During Cesarean Section Under Spinal Anesthesia: Incidence, Risk Factors, and...

Various types of arrhythmia have been reported during cesarean section under spinal anesthesia. But the possible causative factors and the effects of arrhythmia on immediate post-delivery neonatal outcome are not well established.

This prospective observational study was conducted over a period of one year in a tertiary care hospital on women undergoing cesarean section under spinal anesthesia. The objectives of the study were to determine the incidence of arrhythmia, its types, the possible factors influencing arrhythmia, and the immediate post-delivery neonatal outcome. Data collected were analyzed using Statistical Package for the Social Sciences (SPSS) software version 21 (IBM Corp. Armonk, NY).

In our study, the incidence of arrhythmia was 31.9% during cesarean section under spinal anesthesia; and sinus bradycardia was the most common type. Arrhythmia occurred more in women with hypotension, when maximum block height was above T₄ level and dose of intrathecal hyperbaric bupivacaine was more than 2.2 mL (P value <0.05). Also, uterine manipulation led to sudden bradycardia and transient cardiac asystole in two patients which was preceded by subjective symptoms of pain and discomfort. None of the neonates required cardiopulmonary resuscitation or neonatal intensive care unit admission within an hour of birth. APGAR (Appearance (skin color), Pulse (heart rate), Grimace (reflex irritability), Activity (muscle tone), and Respiration) scores at 1 and 5 minutes were similar in all the newborns born to mothers with or without arrhythmia.

The occurrence of arrhythmia during cesarean section under spinal anesthesia, though very common, is rarely life-threatening. Keeping maximum level of block height between T₄ and T_6, using lower possible drug dose to provide adequate level of sensory block, prompt management of hypotension, and strict monitoring during uterine manipulation may reduce the overall incidence of arrhythmia. Intraoperative arrhythmia, however, does not adversely affect the immediate post-delivery neonatal outcome.