Intoxication à l'acide fluorhydrique (HF) : doser le calcium ionisé

Poisoning by hydrofluoric acid (HF) are rare but all the more serious as the chelation of calcium ions is important, as to pose a risk of life-threatening hypocalcemia within one hour after ingestion of a concentrated product. A 42-years-old man ingested 30 mL of a 10% HF rustproof solution. Admitted in ICU one hour later, he presented abdominal pain, bradycardia of 68/min and a QT prolongation suggestive of hypocalcemia. Laboratory tests showed normocalcemia to 2,3 mmol/L but a low ionized calcium blood level to 0,89 mmol/L. Fluorine blood level was 69,5 mol/L high (N: 0,9-1,5). A gastroscopy was performed at H + 2 h 30 under continuous calcium recharge by digestive and intravenously route. It showed a necrotic and circumferential lesion of the lower esophagus topped with a white coating. A scanner has eliminated the risk of a gastrointestinal perforation and/or mediastinitis. Calcium recharge by continuous intravenous was effective on ionized calcium blood level 8 h after the start of the antidote and the ECG is normalized at the same time, without arrhythmia. The H 24 control gastroscopy showed a marked improvement of the lesions, allowing diet. The patient left the hospital a week later after a last endoscopic control showed a complete healing of the lesions. It is possible to be falsely reassured by normal serum calcium on admission of a patient poisoned by this caustic, and a dosage of ionized calcium is essential in this context.