Severe suicidal self-poisoning with massive dose of potassium ferricyanide(III): hyperkalemia but not free cyanide may cause death

Potassium ferricyanide(III), K3[Fe(CN)6], has a widespread use in blueprint drawing, photography, chemical industry, and metallurgy. In mice, the oral lethal dose 50 (LD50) is 1600 mg kg−1. We report the case of a suicide attempt in a 37-year-old male by intentional ingestion of 80 g of potassium ferricyanide(III) dissolved in water. The estimated ingested dose was 770 mg kg−1. The patient reported vertigo as the first sign of poisoning and six episodes of diarrhea with dark-colored stool 2 h after ingestion. The patient was transported by ambulance to the intensive care unit 8 h after ingestion. He was conscious and spontaneously ventilating, with a Glasgow Coma Scale (GCS) score of 15. On ECG performed at admission, tall “tented” T waves in V3–V6 and progressive flattering of P waves were registered. Serum concentrations of potassium of 7.2 mmol dm−3, urea of 7.1 mmol dm−3, and creatinine of 162 µmol dm−3 indicated development of acute renal failure. Despite the administration of intravenous insulin and 10% glucose infusion during the first hours after admission, there was a further elevation of serum potassium to 7.4 mmol dm−3 suggesting acute renal failure. For this reason, intermittent hemodialysis was performed [duration 200 min, blood flow rate 147 cm3 min−1, online clearance monitoring (OCM) clearance rate 100 cm3 min−1, and substitution fluid volume 5.8 dm3]. The condition of the patient stabilized and he was discharged from hospital on the fourth day after admission. This case report demonstrates the risks of life-threatening hyperkalemia and acute renal failure as complications of massive ingestion of potassium ferricyanide(III).