Successful treatment of flecainide-induced cardiac arrest with extracorporeal membrane oxygenation in the ED

2023 American Heart Association Focused Update on the Management of Patients With Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning: An Update to the American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

In this focused update, the American Heart Association provides updated guidance for resuscitation of patients with cardiac arrest, respiratory arrest, and refractory shock due to poisoning. Based on structured evidence reviews, guidelines are provided for the treatment of critical poisoning from benzodiazepines, β-adrenergic receptor antagonists (also known as β-blockers), L-type calcium channel antagonists (commonly called calcium channel blockers), cocaine, cyanide, digoxin and related cardiac glycosides, local anesthetics, methemoglobinemia, opioids, organophosphates and carbamates, sodium channel antagonists (also called sodium channel blockers), and sympathomimetics. Recommendations are also provided for the use of venoarterial extracorporeal membrane oxygenation. These guidelines discuss the role of atropine, benzodiazepines, calcium, digoxin-specific immune antibody fragments, electrical pacing, flumazenil, glucagon, hemodialysis, hydroxocobalamin, hyperbaric oxygen, insulin, intravenous lipid emulsion, lidocaine, methylene blue, naloxone, pralidoxime, sodium bicarbonate, sodium nitrite, sodium thiosulfate, vasodilators, and vasopressors for the management of specific critical poisonings.

A Case Report of Flecainide Toxicity With Review of Literature

Flecainide is an anti-arrhythmic drug with a narrow therapeutic index. Flecainide toxicity is rare, but the mortality is high. This case demonstrates the use of intravenous fat emulsion therapy in conjunction with intravenous sodium bicarbonate treatment for flecainide toxicity.

A 50-year-old male with atrial fibrillation and taking flecainide 75 mg twice daily presented to Emergency Department after ingesting 1125 mg of flecainide, in a suicide attempt. An electrocardiogram (ECG) on arrival showed bradycardia, wide QRS complex, prolonged QTc interval. Treatment for flecainide poisoning with intravenous sodium bicarbonate was initiated. On day two, the patient had a cardiac arrest secondary to ventricular tachycardia. After successful defibrillation, the patient had persistent bradycardia and hypotension. Administration of a 20% lipid emulsion bolus, followed by continuous infusion for three hours, resulted in conversion to normal sinus rhythm.

This case illustrates the successful treatment of flecainide toxicity with intravenous fat emulsion therapy. To our knowledge, this is the second case that used fat emulsion without concomitant extracorporeal life support. Due to its low prevalence and the fact the lipid emulsion is often used in conjunction with other treatments, there are no randomized clinical trials on the isolated efficacy of lipid infusion. The best treatment is unknown. Given its high mortality, early detection and treatment are paramount.

Extracorporeal membrane oxygenation use in poisoning: a narrative review with clinical recommendations

CONTEXT

Poisoning may lead to respiratory failure, shock, cardiac arrest, or death. Extracorporeal membrane oxygenation (ECMO) may be used to provide circulatory support, termed venoarterial (VA) ECMO; or respiratory support termed venovenous (VV) ECMO. The clinical utility of ECMO in poisoned patients remains unclear and guidelines on its use in this setting are lacking.

OBJECTIVES

To perform a literature search and narrative review on the use of ECMO in poisonings. Additionally, to provide recommendations on the use of ECMO in poisonings from physicians with expertise in ECMO, medical toxicology, critical care, and emergency medicine.

METHODS

A literature search in Ovid MEDLINE from 1946 to October 14, 2020, was performed to identify relevant articles with a strategy utilizing both MeSH terms and adjacency searching that encompassed both extracorporeal life support/ECMO/Membrane Oxygenation concepts and chemically-induced disorders/toxicity/poisoning concepts, which identified 318 unique records. Twelve additional manuscripts were identified by the authors for a total of 330 articles for screening, of which 156 were included for this report.

NARRATIVE LITERATURE REVIEW

The use of ECMO in poisoned patients is significantly increasing over time. Available retrospective data suggest that patients receiving VA ECMO for refractory shock or cardiac arrest due to poisoning have lower mortality as compared to those who receive VA ECMO for non-poisoning-related indications. Poisoned patients treated with ECMO have reduced mortality as compared to those treated without ECMO with similar severity of illness and after adjusted analyses, regardless of the type of ingestion. This is especially evident for poisoned patients with refractory cardiac arrest placed on VA ECMO (termed extracorporeal cardiopulmonary resuscitation [ECPR]).

INDICATIONS

We suggest VA ECMO be considered for poisoned patients with refractory cardiogenic shock (continued shock with myocardial dysfunction despite fluid resuscitation, vasoactive support, and indicated toxicologic therapies such as glucagon, intravenous lipid emulsion, hyperinsulinemia euglycemia therapy, or others), and strongly considered for patients with cardiac arrest in institutions which are structured to deliver effective ECPR. VV ECMO should be considered in poisoned patients with ARDS or severe respiratory failure according to traditional indications for ECMO in this setting.

CONTRAINDICATIONS

Patients with pre-existing comorbidities with low expected survival or recovery. Relative contraindications vary based on each center's experience but often include: severe brain injury; advanced age; unrepaired aortic dissection or severe aortic regurgitation in VA ECMO; irreversible organ injury; contraindication to systemic anticoagulation, such as severe hemorrhage.

CONCLUSIONS

ECMO may provide hemodynamic or respiratory support to poisoned patients while they recover from the toxic exposure and metabolize or eliminate the toxic agent. Available literature suggests a potential benefit for ECMO use in selected poisoned patients with refractory shock, cardiac arrest, or respiratory failure. Future studies may help to further our understanding of the use and complications of ECMO in poisoned patients.

Cardiovascular Drug Toxicity

Managing unstable poisoned patients is often associated with clinician cognitive overload. This article summarizes the mechanisms of toxicity; clinical presentations; and the current evidence available for the treatment of cardiovascular drug toxicity due to calcium channel blockers, beta-blockers, cardiac glycosides, and sodium channel blockers. In addition, management approaches are proposed.

First Case of Acute Poisoning with Amiodarone and Flecainide in Attempted Suicide Successfully Managed with Lipid Emulsion Therapy in the Emergency Department: Case Report and Literature Review

Acute antiarrhythmics poisoning represents a challenge in the Emergency Department (ED). These patients often develop malignant arrhythmias in need of exceptional therapeutic measures in the ICU. We report a 47-year-old patient admitted to the ED 5 h after the ingestion of a large dose of amiodarone and flecainide in a suicide attempt. During their ED stay, the patient developed signs of cardiotoxicity evidenced by electrocardiogram and ventricular arrhythmias. The toxicological results showed a level of 4.8 mg/L amiodarone and 2.98 mg/L flecainide. He was successfully treated in the ED using a large dose of sodium bicarbonate and lipid emulsion therapy. After hospital admission, he remained stable, with no need for exceptional therapeutic measures such as mechanical circulatory support, cardiac pacing or ECMO. We emphasize the importance of an early start of pharmacological therapies in the ED, which might improve the outcome in antiarrhythmic acute poisoning.

Complete Heart Block Secondary to Flecainide Toxicity: Is It Time for CYP2D6 Genotype Testing?

Flecainide acetate is a Vaughan-Williams class IC antiarrhythmic drug prescribed for the treatment of supraventricular arrhythmias. It has a narrow therapeutic index and proarrhythmic effects even at therapeutic doses. Flecainide is metabolized by a CYP2D6 enzyme that exhibits polymorphism. In this case report, we present, to our best knowledge, the first case of toxicity contributed by genetic polymorphism in an infant. Our patient with recurrent supraventricular tachycardia was treated with a therapeutic dose of flecainide but developed heart block requiring extracorporeal membrane oxygenation support and subsequent treatment with lipid emulsion therapy. He was found to have supratherapeutic serum flecainide concentration, and gene testing revealed the patient to be an intermediate metabolizer. With this case report, we reinforce the importance of evaluating the CYP2D6 genotype before drug initiation in the neonatal population and recommend regular monitoring of serum flecainide levels and electrocardiograms in these patients.

Flecainide-Associated Cardiogenic Shock in a Patient with Atrial Fibrillation

Flecainide is a frequently used antiarrhythmic drug, recommended by current guidelines as a first-line treatment option for restoring and maintaining sinus rhythm in patients with atrial fibrillation and no significant structural heart disease. In overdose, it can induce severe cardiogenic shock. Cardiogenic shock after a therapeutic dose of flecainide in patients without contraindication has not yet been reported in literature. Case Summary. We report a case of flecainide-associated cardiogenic shock in a 52-year-old woman with paroxysmal atrial fibrillation after a therapeutic dose of flecainide. Pharmacological cardioversion of symptomatic tachyarrhythmic atrial fibrillation with flecainide was unsuccessful and shortly after, she developed cardiogenic shock with severely reduced LVEF. Electrical cardioversion was also unsuccessful. Coronarography was unremarkable, and the cardiac MRI showed no signs of inflammation or fibrosis. After amiodarone loading, she converted to SR. This rare but severe complication despite adequate treatment could be explained by increased susceptibility to negative inotropic effect of flecainide as a consequence of marked tachycardia. Therefore, cautious monitoring after new administration of flecainide or the administration of a higher dose is advisable.

Literature review of the evidence regarding intravenous lipid administration in drug-induced cardiotoxicity

Introduction: Intravenous lipid emulsion (ILE) administration is capable of reversing the acute cardiac and neurological toxicity caused by local anesthetic agents. In recent years, ILE has also been explored as a potential antidote for cardiotoxicity caused by non-anesthetic agents too. Areas covered: The potential mechanisms, safety, and efficacy of this approach are considered. Data were sought from published reports listed in PubMed and EMBASE, and abstracts of meetings of the North American Congress of Clinical Toxicology and European Association of Poisons Centres and Clinical Toxicologists. There were reports involving 298 patients where ILE has been administered for severe drug toxicity. Clinical improvement was observed in 57 of 59 patients with local anesthetic toxicity (96.6%); there were 239 patients where toxicity was due to non-anesthetic agents, and ILE apparently improved clinical outcome in 215 (72.1%). Expert opinion: Response rates were similar between ILE treated toxicity caused by lipid soluble and non-lipid soluble drugs. Potential adverse effects of ILE include interference with laboratory assays, acute pancreatitis, and adult respiratory distress syndrome, although the rate of occurrence is difficult to ascertain.

Three Cases of Cardiac Arrest with Massive Flecainide Intoxication Treated with Extracorporeal Assistance

Flecainide acetate is a Vaughan Williams class 1C anti-arrhythmic agent. Overdose causes severe cardiac and neurologic disturbances and carries a risk of fatality. No antidote is currently available.We present three cases of massive flecainide intoxication in which the patients were kept alive by extracorporeal circulation. Extracorporeal support in cases of flecainide intoxication is the only approach that can alleviate acute cardiac dysfunction, preserve blood flow to vital organs, and maintain liver metabolism and renal excretion of the toxin, while waiting for the improvement of cardiac function. Furthermore, clinical practice highlights that age, duration of CPR, PH, and lactate levels should not be a hindrance to decision-making, and demonstrates the positive, long-term neurologic and cardiologic outcomes that can be achieved with the use of extracorporeal assistance in the setting of severe flecainide intoxication.

Poisoning-induced Out-of-Hospital Cardiac Arrest and Outcomes according to Poison Agent

It is unclear whether specific agent groups are associated with outcomes in cases of poisoning-induced out-of-hospital cardiac arrest (P-OHCA). The study population comprised cases of confirmed P-OHCA drawn from the national out-of-hospital cardiac arrest (OHCA) registry (2008-2013). Exposures were categorized into five groups according to the International Classification of Disease, 10th version: group 1, prescribed drugs; group 2, vapors and gases; group 3, pesticides; group 4, alcohol and organic solvents; and group 5, other poisons. The outcome was survival to discharge and good neurological recovery. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated to test the association between specific groups and outcomes. A total of 2,083 patients were analyzed; group 1 (10.3%), group 2 (23.6%), group 3 (52.9%), group 4 (1.4%), and group 5 (13.2%). The survival to discharge and good neurological recovery rates were 3.3%/1.3% for all patients, 10.3%/5.6% (group 1), 6.9%/3.4% (group 2), 2.4%/0.4% (group 3), 2.2%/1.0% (group 4), and 3.3%/2.4% (group 5) (all P < 0.001). The aORs (95% CIs) of groups 2-5 compared with group 1 for survival to discharge were 0.47 (0.09-2.51), 0.34 (0.17-0.68), 0.33 (0.14-0.77), and 0.31 (0.13-0.77), respectively. The odds ratios (95% CIs) for good neurological recovery were significant only in group 1, the pesticides group (0.07 [0.02-0.26]) and were not significant in the other groups. P-OHCA outcomes differed significantly among the poisoning agent groups. The pesticides group showed the worst outcomes, followed by the group of vapors or gases.

Flecainide toxicity in a preterm neonate with permanent junctional reciprocating tachycardia

We report a case of flecainide toxicity in a premature neonate with permanent junctional reciprocating tachycardia which was managed successfully by reversal of the sodium blockade with intravenous sodium bicarbonate and supportive care. This report highlights the importance of strict supervision and monitoring while administering antiarrhythmic drugs in neonates and prompt institution of appropriate remedial action for treatment when toxicity is suspected.