Faculty Bibliography

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.

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.

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/METHODS: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.

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.