Topical povidone-iodine reduces mortality from bacterial peritonitis

The efficacy of topical 10 and 1.5% povidone-iodine was assessed in a rat fecal peritonitis model. Both solutions were bactericidal in vitro. An LD₉₀ preparation of fecal peritonitis in the rat was then assessed and rats were assigned to control or four treatment groups consisting of lavage with saline, 10% povidone-iodine (2.5 ml/kg), povidone-iodine plus saline (600 ml/kg), or 1% cephalothin (600 ml/kg). Twenty-four-hour mortality rates were recorded. Quantitative peritoneal cultures were obtained before and 3 and 6 hr after lavage. Lavage was effective only with 1.5% povidone-iodine or when cephalothin was added. Each of these lavage solutions significantly reduced mortality (P < 0.05). Delayed intravenous cephalothin (200 mg/kg) reduced mortality significantly following 10 or 1.5% povidone-iodine. Failure of povidone irrigation is due to uncontrolled infection rather than to drug toxicity.