povidone-iodine and Acid-Base-Imbalance

Local infection and burn wound sepsis are one of the most severe problems in the treatment of thermally injured patients. Early surgical treatment and the use of topical antiseptics led to a decrease in the infection rate and significantly improved the survival rate of burns patients within the last twenty-five years. Many antiseptics are used in the treatment of burns. Silver nitrate, silver sulphadiazine, sulfamylon and povidone-iodine (PVP-I) are the most common substances used worldwide in burn care facilities. Clinical studies demonstrate that treatment with PVP-I is the most effective against bacterial and fungal infection. Several methodological problems however arise from direct comparison between these antiseptics, and local and systemic adverse effects can make the right choice difficult. Some case reports documented possible side effects in the treatment of patients with PVP-I, leading to general concerns about this treatment. Absorption of iodine and possible changes in thyroid hormones are well known, but evaluation of the clinical consequences is controversial. Reports of severe metabolic acidosis and renal insufficiency with lethal results have condemned the use of PVP-I in the treatment of extensive burns. The case reports, however, dealt with patients suffering from general morbidity and sepsis and therefore these single reports may not be generally valid. Local treatment of burns may cause further problems. The beneficial effect of a decrease of bacterial counts in deeper tissue may be confounded by other effects delaying wound healing, as shown in some experimental studies. Controlled clinical investigations on burn patients however are still missing. The paper will discuss these topics in detail referring to the treatment of burns with PVP-I. It is based on a critical review of the literature and the author's own experience in burns therapy.

Topics: Acid-Base Imbalance; Adult; Aged; Antisepsis; Burns; Female; Humans; Male; Povidone-Iodine; Thyroid Gland; Wound Healing; Wound Infection

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.

Topics: Absorption; Acid-Base Imbalance; Acidosis; Administration, Topical; Adult; Aged; Bicarbonates; Burns; Creatinine; Female; Humans; Iodine; Kidney; Male; Povidone; Povidone-Iodine; Renal Dialysis; Sodium