(185) Therapeutic Plasma Exchange for Refractory Verapamil Poisoning

Introduction: Verapamil poisoning results in significant morbidity and mortality, but management is challenging due to decreased myocardial contractility and conduction. We present a case of verapamil poisoning requiring ECMO support and the use of therapeutic plasma exchange (TPE) to provide stability and enhance drug clearance.

Description: A 14-year-old female with past medical history of depression presented after intentional ingestion of approximately 4080 mg of extended-release verapamil. She was taken to an outside hospital where her initial vital signs were HR: 96, BP: 79/39, and SaO2: 94% on room air. Her initial glucose was 295mg/dL. She was given calcium gluconate, and epinephrine and norepinephrine infusions were initiated. She progressed to 3rd degree AV block. She was intubated and transferred to a tertiary pediatric intensive care unit (PICU), where upon arrival, she was bradycardic and hypotensive despite high dose epinephrine and norepinephrine infusions. High-dose insulin-euglycemic and lipid emulsion therapy was initiated. Due to her refractory hypotension, she was cannulated onto VA-ECMO. After cannulation with ECMO flows of 100 ml/kg/min, she continued to require high vasoactive support with epinephrine of 0.7 mcg/kg/min, norepinephrine of 0.7 mcg/kg/min, vasopressin of 0.06 units/min, insulin 10 units/kg/hr, and D12.5% at 80 cc/hr. She was initiated on angiotensin II infusion for additional hemodynamic support. TPE with 1.5 plasma volume exchange with all 5% albumin (70% plasma clearance) was performed. The verapamil concentration pre-plasmapheresis was 7500 ng/ml and post plasmapheresis was 1300 mg/ml. This suggests enhanced clearance (half-life is 3-7 hours). In the 24 hours after plasmapheresis, the patient’s vasoactive needs were weaned to epinephrine of 0.5 mcg/kg/min, norepinephrine of 0.46 mg/kg/min, vasopressin of 0.025 units/min, and angiotensin II of 20 mg/kg/min. She was decannulated from ECMO after 5 days and ultimately transferred to an inpatient psychiatric facility.

Discussion: There are limited case reports for the use of TPE in verapamil poisoning. Verapamil is a highly protein bound medication, and the use of TPE may be an important adjunctive therapy to enhance drug clearance.