Etched in Stone: A Case of Fatal Ammonium Bifluoride Poisoning
Bisoski L, Baltarowich L, and Aaron C. Etched in stone: A case of fatal ammonium bifluoride poisoning. Clin Toxicol 2018; 56(10):935.
Background: Ammonium bifluoride and hydrofluoric acid are potent toxins with severe local and systemic toxicity due to high permeability coefficient and binding of divalent cations with disruption of the Na-K-ATPase pump. Case report: A 52-year-old developmentally delayed deaf and mute male with known pica was attending a craft workshop involving glass etching. When the teacher was distracted, he swallowed about 3 ounces of Armour Etch cream. On the initial call to the poison center the patient had vomited, but otherwise appeared well. Immediate transport was requested and he arrived approximately 1-2 h post-ingestion ingestion[c1]. The first SDS stated the product was a proprietary formula with ammonium bifluorides and 1-2% hydrofluoric acid. A more specific SDS was located and which showed 21-27% ammonium bifluoride and a small amount of barium sulfate in the product. This corresponds to 17-23 g of ammonium bifluoride in a 3 ounce ingestion. The patient's presenting vital signs were BP: 126/91, HR: 86, RR: 18, Temperature: 36.6, SpO2: 94% RA. He was reportedly asymptomatic on arrival per ED notes. Initial laboratories were significant for magnesium of 1.7, calcium of 6.8, and potassium of 3.9. An NG tube placement was attempted without success due to agitation. The patient received 3 gm of CaCl2 IV and 2 gm MgSO4. One hour post ED arrival, the patient was sedated and NG tube was placed with clear aspirate obtained. Two hour post ED arrival the patient had respiratory distress, was intubated, and had widening QRS on EKG and rising troponins (ultimately peaking at 89). By 6 h post arrival, transfer arrangements were made and the patient was started on a sodium bicarbonate infusion, antibiotics, and PPI. He was given an additional 5gmCaCl2. The patient's calcium continued to drop as low as <5 and potassium rose as high as 5.3 8 h post arrival. The patient arrested as helicopter transport was packaging for travel. He was unable to be resuscitated despite receiving 5 gm CaCl2, epinephrine, bicarbonate, and amiodarone over a 20min resuscitation attempt. In total, he received 10-12 g of CaCl2 and 2 g of magnesium during his ED stay. Post-mortem showed gastric perforation with barium staining of the peritoneum and mediastinum. Case discussion: Most patients who ingest these products will die; those who survived reportedly received 25-50 g of calcium in the first 24 h. Early decontamination is a challenge because of vomiting. Oral calcium products or lavage with calcium gluconate should be considered. Aggressive calcium and magnesium replacement, correction of acidosis, and CV support are critical management steps. For severe cases, hemodialysis may be considered with case reports demonstrating successful clearance of fluoride ions, although it is unclear if this is helpful in patients with normal renal function. Conclusion: Significant fluoride and hydrofluoric acid ingestions are extremely deadly and management is very challenging. The severity and rapidity of deterioration of patients may be underappreciated.