Complications of povidone-iodine absorption in topically treated burn patients

One of the dangers of topical therapy in thermal injuries is absorption of the therapeutic agent with subsequent metabolic and toxic complications. Two patients, one 30 years old with a 75% burn, the second 72 years old with a 35% burn, were treated topically with povidone-iodine ("Betadine", pH 2.43). In both patients severe metabolic acidosis developed which could not be attributed to sepsis, hypovolaemia, renal failure, diabetes, lactic acidaemia, &c. The acidosis associated with the 75% burn required large amounts of sodium bicarbonate to maintain pH at 7.35 and a serum-bicarbonate concentration of 15 mmol/l (meq/l); serum-iodine was 48000 mug/dl (normal 4-8.5mug/dl). Acidosis in the second patient was not as severe, and serum-iodine concentration reached 17600 mug/dl. The rate of urinary excretion of iodine was 50.8 +/- 7.4 mg/dl and seemed to be fixed. Haemodialysis was very effective in reducing serum-iodine concentration. Povidone was also systemically absorbed. The persistent acidosis could be caused by absorption of the iodine or the acidic povidone-iodine. Until the aetiology of the acidosis and renal damage is more clear, iodophors should not be used topically for burns greater than 20% of the body surface or in the presence of renal failure.