Retained Gastric Substance Requiring Endoscopic Removal in a Patient with Prolonged Toxicity from Acute Metaldehyde...

Metaldehyde is a highly selective molluscicide with moderate water solubility. Acute metaldehyde poisoning is most commonly reported in veterinary medicine and is extremely rare in humans. Its optimal clinical management remains poorly defined and warrants further investigation.

An 81-year-old male presented with altered mental status and respiratory distress. A computed tomography (CT) scan revealed a hyperdense shadow within the gastric cavity. Blue granules were observed in the oral cavity during endotracheal intubation. Given the presence of metaldehyde at his residence, a diagnosis of acute metaldehyde poisoning was made. Despite initial treatment with gastric lavage, catharsis, hemoperfusion, and mechanical ventilation, the patient remained comatose with persistently elevated serum and urine metaldehyde concentrations. A repeat CT scan demonstrated retained hyperdense material in the stomach. Endoscopy subsequently identified and removed residual metaldehyde granules from the gastric fundus. Additionally, the cholinergic receptor antagonist penehyclidine hydrochloride was administered to alleviate muscarinic symptoms. The patient ultimately recovered fully, with no residual neurological deficits. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Metaldehyde toxicity is rarely encountered in the emergency department. Due to its moderate water solubility, oral metaldehyde ingestion can lead to prolonged gastrointestinal retention with delayed elimination and sustained toxicity. Emergency physicians should be aware of this risk and consider repeat imaging and early specialty consultation for endoscopic intervention in patients with persistent severe symptoms after oral metaldehyde ingestion.