EXTRACORPOREAL MEMBRANE OXYGENATION MODALITY DETERMINED BY POINT-OF-CARE ULTRASOUND IN A PATIENT WITH AMLODIPINE OVERDOSE: A CASE REPORT

Abstract

TOPIC: Critical Care TYPE: Medical Student/Resident Case Reports INTRODUCTION: The use of calcium channel blockers (CCB) as first-line antihypertensive therapy has correlated with increased incidences of CCB overdose. Massive CCB overdose proves difficult to manage as patients are prone to refractory distributive shock and noncardiogenic pulmonary edema. Extracorporeal membrane oxygenation (ECMO) has been a successful rescue therapy in CCB overdose. Veno-arterial (VA) ECMO has been the traditional modality used as it provides both cardiac and pulmonary support. However, recent case reports have described successful use of veno-venous (VV) ECMO for CCB overdose when cardiac function is preserved. We present a case of amlodipine overdose where VV ECMO was used instead of VA ECMO. This decision was guided by a point of care ultrasound (POCUS) exam that demonstrated a hyperdynamic left ventricle (LV) and normal right ventricle (RV) function immediately prior to cannulation. The patient subsequently improved, was decannulated, and survived to hospital discharge. CASE PRESENTATION: A 52-year-old male intentionally overdosed with amlodipine (750mg total). Emergency medical services were notified and transported the patient to the nearest critical access hospital. The patient became hypoxic, developed multipressor shock and met criteria for severe acute respiratory distress syndrome. On hospital day two the patient remained hypoxic despite an FiO2 of 1.0, deep sedation, neuromuscular blockade (NMB) and prone positioning. His shock was refractory despite infusions of norepinephrine, epinephrine, vasopressin and phenylephrine in addition to stress dose steroids and methylene blue. Our ECMO team was consulted for intervention. Prior to cannulation, cardiac POCUS revealed a hyperdynamic LV and preserved RV function. This guided our decision to implement VV instead of VA ECMO. The patient was cannulated then transported to our tertiary care institution. On ECMO day 2, the patient came off epinephrine and phenylephrine and NMB was discontinued. On ECMO day 4, the patient remained on norepinephrine alone and followed simple commands during a sedation holiday. On ECMO day 7 the patient no longer required vasopressors and was decannulated. The patient underwent tracheostomy placement, was placed on a long-term ventilator wean and discharged on hospital day 21. DISCUSSION: CCB overdose leading to refractory shock presents a difficult challenge for clinicians. There is promising data regarding the use of VA ECMO and, recently, VV ECMO as a rescue treatment in addition to supportive critical care in these cases. Selection of the appropriate ECMO modality prior to cannulation is paramount to optimize cardiopulmonary support. CONCLUSIONS: We assert that this case demonstrates the potential for utilizing POCUS as a tool to help decide what ECMO modality to use in patients with CCB overdose. Further study into POCUS as a means of determining ECMO modality is warranted. REFERENCE #1: Fadhlillah F, Patil S. Pharmacological and mechanical management of calcium channel blocker toxicity. BMJ Case Rep. 2018;2018:bcr2018225324. Published 2018 Aug 27. doi:10.1136/bcr-2018-225324 REFERENCE #2: Haughey R, Vernick W, Gutsche J, Laudanski K. Use of veno-venous extracorporeal membrane oxygenation to treat severe combined calcium channel blocker and angiotensin converting enzyme inhibitor overdose. Perfusion. 2019 Mar;34(2):167-169. doi: 10.1177/0267659118798181. Epub 2018 Sep 3. PMID: 30175658. REFERENCE #3: Lindeman E, Ålebring J, Johansson A, Ahlner J, Kugelberg FC, Nordmark Grass J. The unknown known: non-cardiogenic pulmonary edema in amlodipine poisoning, a cohort study. Clin Toxicol (Phila). 2020 Nov;58(11):1042-1049. doi: 10.1080/15563650.2020.1725034. Epub 2020 Mar 2. PMID: 32114860. DISCLOSURES: No relevant relationships by Jonathon Davis, source=Web Response No relevant relationships by Jon Greenberg, source=Web Response No relevant relationships by Logan Rosenberg, source=Web Response