Povidone Iodine Sterilization of Contaminated CAPD-Exchange Spikes

Abstract

Thirty routine CAPD exchange spikes (Travenol) were dipped in a Staphylococcus aureus suspension and then divided into three equal groups. Group I (G1) spikes were advanced from the bacterial suspension to a povidone-iodine solution for a five-minute soak; Group 2 (G2) spikes were advanced into a sterile, non-bacteriostatic, physiologic saline solution for a five-minute soak. Then G1 and G2 spikes were attached in the usual sterile fashion to dialysis bags pretreated with tryptic soy broth to enhance bacterial growth. Group 3 (G3) spikes were advanced immediately to pretreated dialysate bags. Cultures of the dialysis solution were obtained immediately after the spikes were connected to the dialysis bags, 48 hours later, and at weekly intervals for three weeks. All 10 of the G3 bags connected to spikes without soaking grew greater than 10 colony forming units/mi of S. aureus by 48 hours. All 10 of the saline soaked G2 bags also demonstrated growth at 48 hours. Only one of the 10 Gl povidone-iodine soaked spike bags grew detectable colonies of bacteria at 48 hours. We conclude that a five-minute povidone-iodine soaking of spikes contaminated with S. aureus usually will prevent bacterial growth but is not a perfect solution to the problems of spike contamination. The frequent occurrence of peritonitis remains the limiting factor to the widespread acceptance of CAPD. Oreopoulos et al proposed that 36.5% of episodes of peritonitis are secondary to contaminations at the connection site during the a CAPD bag exchange (1). Although the exact frequency is unknown, we agree that the likelihood is high that contamination at the time of the exchange is a common mode of bacterial access to the peritoneal cavity. When we established our CAPD programs we instructed our patients to change the tubing if the spike became contaminated. Patients only rarely notified us of this necessity, despite our suspicion that known contamination was occurring. Two of us asked the Bulletin's editors if one could manage spike contamination simply by soaking the spike in povidone-iodine (2). Vas recommended that the tubing be changed because simple soaking would not deal with contamination inside the lumen (3). We decided to study this issue further because we believed that patients would not comply with this recommendation.