An Unexpected Cardiac Arrest After Spinal Anesthesia for a Cesarean Section: A Case Report

Cardiac arrest during pregnancy is a rare but potentially catastrophic event, often requiring rapid, coordinated, multidisciplinary intervention. Neuraxial anesthesia, while generally considered safe and commonly used in obstetric settings, may be associated with severe cardiovascular complications. Among the proposed mechanisms, the Bezold-Jarisch reflex has been implicated in cases of sudden bradycardia and asystole following spinal anesthesia. We report the case of a 39-week pregnant woman who was admitted for urgent cesarean delivery after failed induction of labor. The patient had a history of chronic hypertension, type 2 diabetes mellitus, and obesity, but was clinically stable at baseline. Spinal anesthesia was performed with co-loading of 500 mL of Ringer's lactate. Shortly after the block and repositioning to the supine position, she developed marked hypotension (mean arterial pressure (MAP) < 60 mmHg), severe bradycardia, and subsequent asystole. Cardiopulmonary resuscitation was initiated immediately, with return of spontaneous circulation (ROSC) after administration of 1 mg of intravenous (IV) epinephrine and four minutes of effective chest compressions. An emergent cesarean section was performed under general anesthesia, with delivery of a viable neonate. Postoperative evaluation revealed no underlying cardiac or obstetric pathology, and the patient was discharged with full neurological recovery. A comprehensive diagnostic approach was undertaken, including exclusion of maternal, medical, obstetric, and anesthetic-related causes of cardiac arrest. The temporal association between spinal anesthesia and cardiovascular collapse, in the absence of hemorrhage or underlying cardiac disease, supports the Bezold-Jarisch reflex as the most likely etiology. In this context, reduced preload - likely influenced by prolonged hospitalization and the relatively limited preloading volume of 500 mL - may have contributed to reflex activation in this patient. This case underscores the importance of early recognition of vagally mediated reflexes, such as the Bezold-Jarisch reflex, and highlights the need for prompt resuscitation and coordinated multidisciplinary management. Adequate fluid resuscitation and heightened vigilance are essential to prevent catastrophic outcomes in obstetric anesthesia.