Successful Treatment of Confirmed Severe Bupropion Cardiotoxicity With Veno-Arterial Extracorporeal Membrane Oxygenation Initiation Prior to Cardiac Arrest.

Bupropion is a substituted cathinone (ß-keto amphetamine) norepinephrine/dopamine reuptake inhibitor andnoncompetitive nicotinic acetylcholine receptor antagonist that is frequently used to treat major depressive disorder. Bupropion overdose can cause neurotoxicity and cardiotoxicity, the latter of which is thought to be secondary to gap junction inhibition and ion channel blockade. We report a patient with a confirmed bupropion ingestion causing severe cardiotoxicity, for whom prophylactic veno-arterial extracorporeal membrane oxygenation (ECMO) was successfully implemented. The patient was placed on the ECMO circuit several hours before he experienced multiple episodes of hemodynamically unstable ventricular tachycardia, which were treated with multiple rounds of electrical defibrillation and terminated after administration of lidocaine. Despite a neurological examination notable for fixed and dilated pupils after ECMO cannulation, the patient completely recovered without neurological deficits. Multiple bupropion and hydroxybupropion concentrations were obtained and appear to correlate with electrocardiogram interval widening and toxicity.

Minding the osmol gap: a sentinel event and subsequent laboratory investigation.

INTRODUCTION: Many hospitals are unable to determine toxic alcohol concentrations in a clinically meaningful time frame. Thus, clinicians use surrogate markers when evaluating potentially poisoned patients. INDEX CASE: A patient presented after an intentional antifreeze (ethylene glycol) ingestion with an osmol gap of -10.6 that remained stable one hour later. Further investigation revealed that the serum osmolality was calculated and not measured. The true osmol gap was 16.4, which correlated to a measured ethylene glycol concentration of 808 mg/L (80.8 mg/dL, 13.0 mmol/L). SURVEY: A telephone survey of hospital laboratories in our catchment area was performed to investigate the potential for similar events. RESULTS: Thirty-eight (47 percent) hospitals responded. No laboratories were able to test for toxic alcohols. One hospital (2.6 percent) reported routinely calculating osmolality based on chemistries, while two hospitals (5.3 percent) reported scenarios in which this might occur. Thirty-five (92.1 percent) hospitals could directly measure osmolality. Two hospitals (5.3 percent) were reliant on outside laboratories for osmolality measurement. LIMITATIONS: The 47 percent response rate and one geographic area are significant limitations. DISCUSSION: Over 10 percent of hospitals that responded could have significant difficulty assessing patients with toxic alcohol ingestion. CONCLUSIONS: Until the standard of rapidly obtaining toxic alcohol concentrations is broadly implemented, we recommend that policies and procedures be put in place to minimize errors associated with the determination of the osmol gap.

Magnetic resonance imaging in a patient with nitrous oxide-induced subacute combined degeneration of the spinal cord.

INTRODUCTION: Chronic nitrous oxide use can lead to neurological findings that are clinically and radiographically identical to those found in patients with pernicious anemia, specifically subacute combined degeneration of the spinal cord and peripheral neuropathy. CASE SUMMARY: A 22-year-old man presented with lower extremity weakness and ataxia in the setting of inhaling 250 nitrous oxide cartridges two to three times weekly for two years. IMAGES: Magnetic resonance imaging showed T2 hyperenhancement of the dorsal columns of the cervical spine from the first to the sixth vertebrae, which helped to establish a diagnosis of nitrous oxide-induced subacute combined degeneration of the spinal cord. CONCLUSIONS: Chronic nitrous oxide use should be included in the differential diagnosis of any patient with otherwise unexplained neurological complaints that localize to the dorsal columns and has the changes on magnetic resonance imaging described here.

An international survey of the treatment of massive paracetamol overdose in 2023.

INTRODUCTION: Changes in the commercialization of nonprescription drugs have made large quantities of paracetamol available to individuals, resulting in larger overdoses than previously observed. Although most patients with paracetamol overdose can be managed with acetylcysteine, patients with a massive overdose may become critically ill earlier and fail standard antidotal therapy. Several strategies are proposed for the management of these patients, including using increased doses of acetylcysteine, extracorporeal removal, and fomepizole. However, the benefits of these strategies remain largely theoretical, with sparse evidence for efficacy in humans. METHODS: This cross-sectional study surveys international practice patterns of medical toxicology providers regarding the management of a hypothetical patient with a massive paracetamol overdose. RESULTS: A total of 342 responses from 31 different nations were obtained during the study period. Sixty-one percent of providers would have increased their acetylcysteine dosing when treating the hypothetical massive overdose. Thirty percent of respondents recommended an indefinite infusion of acetylcysteine at 12.5 mg/kg/hour after the bolus dose, whereas 20 percent recommended following the "Hendrickson" protocol, which advocates for a stepwise increase in acetylcysteine dosing to match high paracetamol concentrations at the 300 mg/L, 400 mg/L, and 600 mg/L lines on the Rumack-Matthew nomogram. Ten percent of respondents stated they would have given "double dose acetylcysteine" but did not specify what that entailed. Forty-seven percent of respondents indicated that they would have given fomepizole, and 28 percent of respondents recommended extracorporeal removal. DISCUSSION: Our survey study assessed the approach to a hypothetical patient with a massive paracetamol overdose and demonstrated that, at minimum, most respondents would increase the dose of acetylcysteine. Additionally, almost half would also include fomepizole, and nearly one-third would include extracorporeal removal. CONCLUSIONS: There is considerable international variation for the treatment of both non-massive and massive paracetamol overdoses. Future research is needed to identify and standardize the most effective treatment for both non-massive and massive paracetamol overdoses.

Insulin concentrations following termination of high-dose insulin euglycemic therapy.

INTRODUCTION: High-dose insulin therapy is used in patients with calcium channel blocker and beta-adrenergic antagonist overdoses. The pharmacokinetics of insulin are scantly reported following high-dose insulin therapy. We present two cases of persistently elevated insulin concentrations following high-dose insulin therapy. CASE REPORTS: A 50-year-old woman and a 45-year-old man experienced hypotension after overdosing on amlodipine and atenolol. They were treated with high-dose insulin therapy for 54 hours at 2 units/kilogram/hour and 48 hours at 10 units/kilogram/hour, respectively. Following termination, serum insulin elimination was studied. Insulin concentrations remained greater than 1,000 µU/mL (fasting reference 2.6-24.9 µU/mL) for longer than 4 hours (case 1) and 11 hours (case 2) and greater than 300 µU/mL for longer than 8 hours and 21 hours, respectively. Insulin concentrations decreased with apparent first-order elimination half-lives of 13.0 hours and 6.0 hours. DISCUSSION: Following high-dose insulin therapy, insulin concentrations remained elevated for longer than expected based on normal pharmacokinetics in therapeutic dosing. Three previous cases reported insulin half-lives of between 2.2 hours and 18.7 hours. The current cases add to the existing data that insulin has a variable but prolonged half-life following high-dose insulin therapy. CONCLUSIONS: These findings suggest that patients are at prolonged risk of hypoglycemia following cessation of high-dose insulin infusions.

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, ß-adrenergic receptor antagonists (also known as ß-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.

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, ß-adrenergic receptor antagonists (also known as ß-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.

Confirmed Fatal Colchicine Poisoning in an Adolescent with Blood and Bile Concentrations-Implications for GI Decontamination?

INTRODUCTION: Colchicine is commonly used to treat diseases like acute gouty arthritis. However, colchicine has a very narrow therapeutic index, and ingestions of > 0.5mg/kg can be deadly. We report a fatal acute colchicine overdose in an adolescent. Blood and postmortem bile colchicine concentrations were obtained to better understand the degree of enterohepatic circulation of colchicine. CASE REPORT: A 13-year-old boy presented to the emergency department after acute colchicine poisoning. A single dose of activated charcoal was administered early but no other doses were attempted. Despite aggressive interventions such as exchange transfusion and veno-arterial extracorporeal membrane oxygenation (VA-ECMO), the patient died 8 days later. Postmortem histology was notable for centrilobular necrosis of the liver and a cardiac septal microinfarct. The patient's blood colchicine concentration on hospital days 1 (~30 hours post-ingestion), 5, and 7 was 12ng/mL, 11ng/mL, and 9.5ng/mL, respectively. A postmortem bile concentration obtained during autopsy was 27ng/mL. DISCUSSION: Humans produce approximately 600mL of bile daily. Assuming that activated charcoal would be able to adsorb 100% of biliary colchicine, using the bile concentration obtained above, only 0.0162mg of colchicine per day would be able to be adsorbed and eliminated by activated charcoal in this patient. CONCLUSION: Despite supportive care, activated charcoal, VA-ECMO, and exchange transfusion, modern medicine may not be enough to prevent death in severely poisoned colchicine patients. Although targeting enterohepatic circulation with activated charcoal to enhance elimination of colchicine sounds attractive, the patient's low postmortem bile concentration of colchicine suggests a limited role of activated charcoal in enhancing elimination of a consequential amount of colchicine.

Extracorporeal treatment for ethylene glycol poisoning: systematic review and recommendations from the EXTRIP workgroup.

Ethylene glycol (EG) is metabolized into glycolate and oxalate and may cause metabolic acidemia, neurotoxicity, acute kidney injury (AKI), and death. Historically, treatment of EG toxicity included supportive care, correction of acid-base disturbances and antidotes (ethanol or fomepizole), and extracorporeal treatments (ECTRs), such as hemodialysis. With the wider availability of fomepizole, the indications for ECTRs in EG poisoning are debated. We conducted systematic reviews of the literature following published EXTRIP methods to determine the utility of ECTRs in the management of EG toxicity. The quality of the evidence and the strength of recommendations, either strong ("we recommend") or weak/conditional ("we suggest"), were graded according to the GRADE approach. A total of 226 articles met inclusion criteria. EG was assessed as dialyzable by intermittent hemodialysis (level of evidence = B) as was glycolate (Level of evidence = C). Clinical data were available for analysis on 446 patients, in whom overall mortality was 18.7%. In the subgroup of patients with a glycolate concentration ≤ 12 mmol/L (or anion gap ≤ 28 mmol/L), mortality was 3.6%; in this subgroup, outcomes in patients receiving ECTR were not better than in those who did not receive ECTR. The EXTRIP workgroup made the following recommendations for the use of ECTR in addition to supportive care over supportive care alone in the management of EG poisoning (very low quality of evidence for all recommendations): i) Suggest ECTR if fomepizole is used and EG concentration > 50 mmol/L OR osmol gap > 50; or ii) Recommend ECTR if ethanol is used and EG concentration > 50 mmol/L OR osmol gap > 50; or iii) Recommend ECTR if glycolate concentration is > 12 mmol/L or anion gap > 27 mmol/L; or iv) Suggest ECTR if glycolate concentration 8-12 mmol/L or anion gap 23-27 mmol/L; or v) Recommend ECTR if there are severe clinical features (coma, seizures, or AKI). In most settings, the workgroup recommends using intermittent hemodialysis over other ECTRs. If intermittent hemodialysis is not available, CKRT is recommended over other types of ECTR. Cessation of ECTR is recommended once the anion gap is < 18 mmol/L or suggested if EG concentration is < 4 mmol/L. The dosage of antidotes (fomepizole or ethanol) needs to be adjusted during ECTR.

Retrospective evaluation of management guidelines for extracorporeal treatment of metformin poisoning.

INTRODUCTION: The Extracorporeal Treatments in Poisoning (EXTRIP) Workgroup defined criteria for extracorporeal toxin removal in patients with metformin poisoning. The primary objective of this study was to determine the benefit of extracorporeal toxin removal in patients meeting EXTRIP criteria. The secondary objective was to determine the performance characteristics of the EXTRIP criteria. METHODS: This was a single-center retrospective analysis of metformin poisoned patients. Inclusion criteria were: suspicion of metformin poisoning with at least one of the following present: lactate concentration >5 mmol/L; pH < 7.35; or impaired kidney function. Patient data were extracted by reviewers who were unaware of the study hypothesis. Cases were analyzed based on EXTRIP criteria, whether extracorporeal toxin removal was performed, and survival. Sensitivity, specificity, negative predictive value and positive predictive value were calculated with respect to the EXTRIP criteria and survival. RESULTS: Of 201 patients studied, 145 patients met recommended EXTRIP criteria (EXTRIP positive) and 56 patients did not (EXTRIP negative). Among patients who met recommended EXTRIP criteria, 96 received extracorporeal toxin removal and 49 did not. There was no difference in survival between these groups: 75.0% versus 73.5%, respectively (P >0.05). All 56 patients who did not meet EXTRIP criteria, survived (negative predictive value = 100%). DISCUSSION: The study did not demonstrate a survival benefit for extracorporeal toxin removal in those meeting EXTRIP criteria. CONCLUSION: In this retrospective analysis, the recommended EXTRIP criteria had a negative predictive value for death of 100%. Further study is needed to evaluate the benefit of extracorporeal toxin removal in patients meeting EXTRIP criteria for metformin poisoning.

Confirmed Grayanotoxin Poisoning with Bradycardia from a Gift of Imported Honey.

BACKGROUND: Human grayanotoxin poisoning is distinctly uncommon in North America, as the predominant source of human exposure is honey made by bees pollinating rhododendron species in the Mediterranean. We present a case of confirmed grayanotoxin poisoning from honey imported from Turkey. CASE REPORT: A 61-year-old man developed nausea, lightheadedness, and lost consciousness. Onset was 30 min after the ingestion of honey that was brought to the United States from Turkey. Emergency medical services found him bradycardic, hypotensive, and unresponsive. He was treated with atropine, saline, and oxygen, at which point his heart rate and blood pressure improved, and he regained consciousness. A similar episode several days earlier was followed by a brief unrevealing hospitalization. He was again hospitalized, and had a normal echocardiogram, telemetric monitoring, and complete laboratory studies. Grayanotoxins I and III were subsequently identified in the patient's blood, urine, and honey. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Grayanotoxins are diterpenoids found in rhododendron species, whose clinical effects span multiple organ systems including gastrointestinal, cardiac, and neurologic. Treatment is largely supportive, and a good response to atropine and intravenous fluids has been described. Laboratory confirmation of grayanotoxins is not available in a short enough turnaround time to be clinically useful during immediate management, but confirmatory testing may obviate further unnecessary evaluation. Grayanotoxins are likely to remain a rare source of poisoning in North America, but recurrent bradycardia without alternative etiology should prompt a thorough exposure history, which may reveal, as in this case, a treatable toxicologic etiology.

Detectable Digoxin Concentrations in 3 Patients with Ramps Misadventure.

Allium tricoccum (commonly known as "ramps") is an edible plant known for its strong garlic-like odor and onion flavor. Unfortunately, A tricoccum mimics such as Lily of the Valley (Convallaria majalis) and False Hellebore (Veratrum viride) can lead to foraging errors and subsequent patient harm/toxicity. We describe 3 adults who foraged and ate what they believed were A tricoccum and then subsequently became symptomatic with detectable digoxin concentrations. A 41-y-old woman, 41-y-old man, and a 31-y-old man presented to the emergency department after ingesting an unknown plant that was believed to be A tricoccum. On arrival to the emergency department, the patients were hypotensive and bradycardic. They had detectable digoxin concentrations ranging from 0.08 ng·mL-1 to 0.13 ng·mL-1. One patient received 20 vials of digoxin antibody fragments. All 3 patients recovered without complication. Laboratory analysis of plant specimen was positive for cyclopamine, a teratogenic alkaloid found in Veratrum californicum. A tricoccum foraging errors can be a source of morbidity given their similarity in appearance to plants like C majalis and V viride. C majalis causes a detectable digoxin concentration via its cardiac steroid compound (convallatoxin) that is similar to digoxin. V viride contains alkaloid compounds (such as veratridine) that can cross react with digoxin assays and lead to a falsely elevated digoxin concentration. Clinicians should be prompted to think about ingestion of C majalis or Veratrum spp. when patients present with bradycardia, gastrointestinal symptoms, and detectable digoxin concentrations after plant ingestion and/or foraging for A tricoccum.

The Management of Agitated Toxidromes.

Taking care of patients with agitated toxidromes can be challenging. While many will be able to be discharged from the emergency department or transferred to psychiatry following brief and simple interventions others will have life-threatening toxicity. Health care providers must develop an organized approach to the assessment and management of these patients that includes foremost the protection of the patient and staff from physical harm, prompt pharmacologic control to allow rapid assessment for life-threatening abnormalities such as hypoglycemia and hyperthermia and optimal cooling of patients with extreme temperature elevations.

Treating ethylene glycol poisoning with alcohol dehydrogenase inhibition, but without extracorporeal treatments: a systematic review.

CONTEXT: Ethylene glycol is metabolized to toxic metabolites that cause acute kidney injury, metabolic acidemia, and death. The treatment of patients with ethylene glycol poisoning includes competitively inhibiting alcohol dehydrogenase with ethanol or fomepizole to prevent the formation of toxic metabolites, and extracorporeal treatments such as hemodialysis to remove ethylene glycol and its metabolites. In the absence of significant metabolic acidemia or kidney injury, it is hypothesized that extracorporeal treatments may be obviated without adverse outcomes to the patient if alcohol dehydrogenase inhibitors are used. OBJECTIVES: The objectives of this study are to: (1) identify indicators predicting ADH inhibitor failure in patients with ethylene glycol poisoning treated with either ethanol or fomepizole for whom extracorporeal treatment was not performed (aside from rescue therapy, see below) (prognostic study), and (2) validate if the anion gap, shown in a previous study to be the best surrogate for the glycolate concentration, is associated with acute kidney injury and mortality (anion gap study). METHODS: We conducted a systematic review to identify all reported patients with ethylene glycol poisoning treated without extracorporeal treatments but with either fomepizole (fomepizole monotherapy) or ethanol (ethanol monotherapy). Analyses were performed using both one case per patient and all cases (if multiple events were reported for a single patient). Data were compiled regarding poisoning, biochemistry, and outcomes. Treatment failure was defined as mortality, worsening of acid-base status, extracorporeal treatments used as rescue, or a worsening of kidney or neurological function after alcohol dehydrogenase inhibition was initiated. Also, we performed an analysis of previously described anion gap thresholds to determine if they were associated with outcomes such as acute kidney injury and mortality. RESULTS: Of 115 publications identified, 96 contained case-level data. A total of 180 cases were identified with ethanol monotherapy, and 231 with fomepizole monotherapy. Therapy failure was noted mostly when marked acidemia and/or acute kidney injury were present prior to therapy, although there were cases of failed ethanol monotherapy with minimal acidemia (suggesting that ethanol dosing and/or monitoring may not have been optimal). Ethylene glycol dose and ethylene glycol concentration were predictive of monotherapy failure for ethanol, but not for fomepizole. In the anion gap study (207 cases), death and progression of acute kidney injury were almost nonexistent when the anion gap was less than 24 mmol/L and mostly observed when the anion gap was greater than 28 mmol/L. CONCLUSION: This review suggests that in patients with minimal metabolic acidemia (anion gap <28 mmol/L), fomepizole monotherapy without extracorporeal treatments is safe and effective regardless of the ethylene glycol concentration. Treatment failures were observed with ethanol monotherapy which may relate to transient subtherapeutic ethanol concentrations or very high ethylene glycol concentrations. The results are limited by the retrospective nature of the case reports and series reviewed in this study and require prospective validation.