Povidone iodine and skin disinfection before initiation of epidural anesthesia

Background: Povidone iodine (PI) solution is used commonly for skin disinfection before epidural and spinal anesthesia. Although there have been reports indicating the presence of microbial contaminants in PI solution, none have evaluated the prevalence of PI contamination. The aims of this study were to assess the frequency of bacterial contamination of previously opened bottles of PI solution and to compare the effectiveness of new and previously opened bottles of PI solution for skin disinfection. Methods: Twenty previously opened and ten previously unopened multiple-use bottles of PI solution were evaluated for microbial contamination. In addition, final swabs and PI solution used for skin disinfection in 80 patients undergoing elective epidural analgesia were evaluated. Results: The inside of the bottle cap or the PI solution from 40% of the multiple-use PI bottles in use were contaminated. There was no growth from any previously unused PI bottles. Povidone iodine from newly opened bottles provided more effective skin decontamination than did solution from previously opened bottles. Conclusions: Multiple-use PI bottles in normal use may become contaminated by bacteria. In addition, PI solution from previously opened bottles was less effective than PI from previously unopened bottles. Based on these findings, if PI solution is chosen for skin antisepsis before initiation of epidural and spinal anesthesia, only single-use containers should be used.