With respect to human EB toxicity, there is only one other documented case in the literature by Yen and Lin.7 In their case, the authors report on a patient who ingested 100 mL of Proclaim, which contained 2.15% EB diluted with 400 mL of tap water.7 They note that the patient in their case presented with mild confusion and gastrointestinal (GI) symptoms of nausea, vomiting, and cramping discomfort. Following laboratory and radiological investigation, the patient was found to have aspiration pneumonitis and admitted to the inpatient hospital. On hospital day 2, the patient’s GI symptoms abated and he became alert and oriented. He was discharged 1 week from initial presentation and experienced no sequelae.
In our case, the patient ingested 100 mL of 2.15% EB without dilution. He also experienced GI symptoms, but did not have any CNS depression. The metabolic acidosis rapidly worsened, and could not be corrected, even with intensive therapy. This rapid life-threatening course has not previously been reported with avermectin or EB poisoning. In the avermectin poisoning cases in the literature, seven out of 19 patients (37%) exhibited severe effects, such as hypotension, coma, and aspiration with respiratory failure.9 Six of the seven patients experienced a full recovery; the remaining patient died 18 days after ingestion from multiple organ failure.
The reason for our patient’s rapid progression to metabolic acidosis and progressive deterioration (hypotension and hypoxemia) is not clear. One possible theory is that the solvents or other additives aside from EB in the ingested insecticide might make EB more toxic. In our case, the patient’s rapid deterioration alone or asphyxia by vomitus might have been the cause of the cardiac arrest. Future reports and studies about EB toxicity in humans are warranted to investigate the pathogenesis of toxicity and appropriate treatment.
Conclusion
This is the first report of a human death caused by EB poisoning; the patient experienced severe metabolic acidosis without CNS depression, ultimately leading to death. Emergency physicians should be aware of the possibility of rapid deterioration in patients who present after ingestion of EB and related substances.