A case illustrating the effect of calcium disodium versenate (CaNa2E.D.T.A.) on chronic mercury poisoning.

Case Report The patient was a girl of 24 who had worked for six months in a factory " throwing " coils. This process consisted of calibrating coils containing mercury for use as pressure gauges. On an average, two or three coils a day burst during testing, so that the work bench was usually contaminated with metallic mercury. Despite warnings about the danger of ingesting mercury, she ate sweets at work and had a habit of sucking her fingers. She had felt unwell for about a month before admission, with general lassitude, anorexia, and loss of weight. She had noticed a metallic taste in her mouth but denied excess salivation and her teeth and gums were healthy. She was admitted to hospital on July 6, 1957, oedema of the ankles, hands, and eyelids having been noted on the previous day. There was no other abnormality on physical examination. Blood pressure was 125/80 mm. Hg. Investigations on admission showed marked albuminuria, 900 mg. per 100 ml. There were no pus cells or casts in the urine and only occasional red cells. Haemoglobin was 98 % and the blood urea level 40 mg. %, serum proteins 5 g. (albumin 3.2 g., globulin 1.8 g.). The urinary mercury excretion in 24 hours was 460 ,ug. The normal excretion of urinary mercury is less than 100 Htg. in 24 hours (Bidstrup, Bonnell, Harvey, and Locket, 1951). With bed rest and a low-protein diet, the oedema cleared, urinary output improved, and the metallic taste disappeared, but albuminuria persisted and the urinary mercury excretion was higher at 475 ,ug. on July 24. A course of B.A.L. was given, consisting of 2 ml. injections of 5% solution, three times on the first day, twice on the second, and then daily for two days. This did not increase the urinary mercury excretion (Fig. 1) and was followed by nausea and an increase in albuminuria. A five-day course of intravenous CaNa2E.D.T.A.. 3 g. daily, was started on August 4 and was followed by a rise in urinary mercury excretion to 700 leg. in 24 hours on August 9. A course of oral CaNa2E.D.T.A., 3 g. daily for seven days, starting on August 14, did not increase urinary mercury excretion: unfortunately the faecal mercury excretion was not measured. By August 21, the oedema had cleared and albuminuria decreased. A further course of CaNa2E.D.T.A. intravenously in the same dosage as before again increased the urinary mercury excretion. The patient was discharged well, free from albuminuria, some three months after admission. Fig. 1 shows the treatment given and urinary mercury and protein excretion.