Local Anesthetic Systemic Toxicity in an Infant Following a Caudal Block: A Case Report and Review of Literature.

Local anesthetic systemic toxicity (LAST) is a rare but serious complication of regional anesthesia, particularly in neonates and infants due to their immature hepatic metabolism, reduced protein-binding capacity, and increased vascular absorption. We report the case of a two-month-old ex-premature infant who developed ventricular fibrillation following a caudal block with bupivacaine during hernia repair and circumcision. Despite negative aspiration tests, systemic absorption of bupivacaine led to toxic plasma concentrations, resulting in sudden cardiovascular collapse without preceding neurological symptoms, a presentation typical in pediatric LAST. Immediate resuscitation, including cardiopulmonary resuscitation, epinephrine, and lipid emulsion therapy, successfully restored normal cardiac rhythm. This case underscores the importance of vigilance, strict adherence to weight-based dosing, and the availability of lipid emulsion therapy in pediatric anesthesia while emphasizing prevention through careful technique, monitoring, and the use of ultrasound guidance to minimize the risk of this life-threatening complication.