Clinical Practice and Cases in Emergency Medicine

Introduction: While the use of venoarterial extracorporeal membrane oxygenation (VA-ECMO) becomes increasingly commonplace in overdose, questions about its role in various shock states remain. The application of VA-ECMO with impaired myocardial function is well established, and use in cardiogenic shock precipitated by poisoning has continued to increase. In poison-induced vasoplegia with preserved myocardial function, the role of VA-ECMO remains undefined. Many atypical antipsychotic and antidepressant agents are known to cause mild hypotension via alpha-1 adrenergic blockade. Intravenous fluids and vasopressors alone are generally effective for single-substance ingestions. In the setting of polysubstance intoxication, synergism leading to bradycardia and refractory vasoplegia refractory to conventional therapies may result, prompting consideration for extracorporeal support. 

Case Report: A 71-year-old woman presented to the emergency department (ED) after being found obtunded near bottles of quetiapine, olanzapine, trazodone, mirtazapine, levomilnacipran, eszopiclone, and clonazepam. She underwent prehospital intubation and received push-dose epinephrine for hypotension. In the ED, the patient remained hypotensive with a relative bradycardia, requiring escalating doses of norepinephrine, vasopressin, epinephrine, angiotensin II, and methylene blue infusions. Her extremities remained warm, and point-of-care echocardiography revealed hyperdynamic function, consistent with vasoplegic shock. She subsequently underwent VA-ECMO cannulation, which was followed by a rapid decrease in vasopressor requirements and decannulation on hospital day 3. The patient recovered and was transferred to inpatient psychiatry neurologically intact. Urine mass-spectrometry revealed large peaks for quetiapine, olanzapine, milnacipran, mirtazapine, trazodone, and zopiclone. 

Conclusion: While overdose data are limited, levomilnacipran may precipitate or potentiate relative bradycardia with hypotension and a preserved ejection fraction. Significant ingestions and synergism with other agents causing peripheral alpha-1 antagonism may lead to hemodynamic instability refractory to conventional therapies. Extracorporeal life support may aid in recovery.