Complications of Acute Formic Acid Poisoning: A Series of Five Cases

Abstract

Formic acid poisoning, although uncommon, carries a high-risk of morbidity and mortality. Five cases (one male and four females) of formic acid poisoning were referred to the Emergency Department within a time frame of 60-120 minutes after ingestion. The age range was between 14 years and 70 years. Three patients had accidental ingestion, while two had ingested the substance with suicidal intent. The quantity ingested ranged from 15-30 mL of undiluted acid. Out of the five patients, two had hypertension, one had both hypertension and diabetes mellitus, and the remaining two did not have any co-morbidities. All five patients presented with orofacial burns, upper abdominal discomfort and dysphagia. One patient experienced mild haematemesis, while another had severe haematemesis. Three patients had altered sensorium due to metabolic acidosis. Four patients developed dark, cola-coloured urine and one had gross haematuria. All patients exhibited acute renal toxicity and dyselectrolytemia. Metabolic acidosis was corrected in two patients with a 7.5% NaHCO3 infusion. Four patients improved with haemodialysis and other supportive measures and were discharged within 10-16 days of admission. However, a 60-year-old patient who had gross haematuria and severe haematemesis following the accidental ingestion of 30 mL of acid expired due to severe metabolic acidosis and hypovolemic shock within eight hours of hospital admission.

Keywords

• haematuria
• haemoglobinuria
• haematemesis
• metabolic acidosis