Soluble barium salts, commonly used in industrial fields, are highly toxic. Hypokalemia, arrhythmia and weakness are the common signs of barium salt poisoning and the lethal dose is thought to be about 1.0g. A 21-year-old man complained of vomiting, diarrhea and a tingling sensation after the accidental ingestion of barium chloride. Hypokalemia (3.2mEq/l) and electrocardiogram abnormality (giant U-wave) were also observed. The patient ingested only about 0.1g of barium chloride, but plasma barium concentration was 8.5μM (measured by ICP-AES; inductively coupled plasma emission spectroscopy). Other laboratory findings were normal. Magnesium sulphate was given orally (40g) for antagonistic action against that of barium and therapeutically 40mEq of potassium was infused intravenously over 6 hours. Potassium excretion into urine was 30.6mEq over 24 hours. At 45 hours after admission, plasma potassium had recovered to 4.3mEq/l. Electrocardiogram normalized within 3 hours, and gastrointestinal and neurological signs were absent by the next morning.The mechanism of cardiac toxicity in barium chloride poisoning has not yet been clearly defined. Although some of the ECG changes may be associated with hypokalemia, a Ca channel blocking mechanism could also be responsible.
