INTRA-PERITONEAL POVIDONE-IODINE IN EXPERIMENTAL CANINE AND MURINE PERITONITIS

In dogs with appendicitis-peritonitis, intraperitoneal povidone-iodine caused death more rapidly than the instillation of saline solution. The bacterial content of canine peritoneal fluid increased with time. Although fewer bacteria were found in fluid from povidone-iodine-treated dogs, the differences were not statistically significant. Qualitative chemical analysis of peritoneal fluid revealed iodide, but not free iodine, 15 to 30 minutes after instillation of povidone-iodine. Iodide was present in the peritoneum at 2 hours but not at 3 or 6 hours. The antibacterial effect of povidone-iodine was demonstrated in mice challenged intraperitoneally with lethal doses of Escherichia coli. Povidone-iodine diminished mortality when injected immediately (p < 0.005) but not when given 1 to 3 hours later. Immediate injection of povidone-iodine into mice lowered the number of E. coli by 3 logs. Injection of povidone-iodine 3 hours after bacterial challenge lowered the number of E. coli by only 1 3 log. This lesser bactericidal effect in mice is attributed to greater dispersal and sequestration of bacteria throughout the peritoneal cavity with time and with inactivation of povidoneiodine by reduction to iodide in vivo. In dogs with appendicitis-peritonitis, the more rapid death after treatment with povidone-iodine was not associated with differences in peritoneal microflora but with peritoneal absorption of excessive amounts of iodide. © 1979.