Cerebral oedema associated with hyponatraemia in renal failure.

Case report A 47-year-old woman was admitted to the Royal Sussex County Hospital on 11 June 1968 in renal failure due to chronic pyelonephritis. Investigations. Hb 52%4, WBC 7200/m3, blood urea 346 mg/100 ml, creatinine clearance 4-2 ml/min, serum sodium 140 mEq/l, calcium 8-0 mg/100 ml, phosphate 12-2 mg/100 ml, alkaline phosphatase 16-0 KA Units; urinary sodium 26 mEq/l, potassium 22-3 mEq/l, urea 870 mg/100 ml, albumin 0-02 g/100 ml. A catheter specimen of urine cultured Ps. pyocyaneus and Esch. coli. Urinary output was 1-2 I/day. She responded well to treatment with peritoneal dialysis, sodium restriction and antibiotics. In August 1968, however, she was readmitted in cardiac failure, conscious, but drowsy. Blood pressure 160/100 mmHg. Her investigations were as follows: blood urea 370 mg/100 ml, serum sodium 150 mEq/l, potassium 5 0 mEq/l, alkali reserve 10 mEq/l, urinary sodium 77 mEq/l, potassium 6-1 mEq/l, urea 430 mg/100 ml, blood glucose 58 mg/100 ml. There was again a heavy growth ofPs.pyocyaneus in the urine. She was treated with peritoneal dialysis for 2 days, and she improved initially. Peritoneal dialysis was discontinued after 2 days. Thereafter, however, her serum sodium fell, and on the morning of the fourth day after admission it was 126 mEq/l. During the evening she had grand mal fits and became deeply unconscious, and artificial ventilation was required. Her condition deteriorated rapidly, the pupils were fixed and dilated, and she developed papilloedema. At that time serum sodium was 122 mEq/l, potassium 5 0 mEq/1; blood urea 150 mg/100 ml, alkali reserve 14 mEq/l, and blood glucose 325 mg/100 ml.