Questions About PD
We thank you for your excellent question. In the latest ISPD peritonitis guidelines (2016), the recommendation is that for suspected peritonitis, the collection of PD effluent in blood-culture bottles is the preferred technique for bacterial culture (1). However, the authors of these 2016 guidelines don’t comment on how to clean the rubber septum of the blood culture bottles to prevent contamination. We would recommend following the guidelines of the U.S. Centers for Disease Control and Prevention (CDC); that is, “disinfect (blood) bottle tops with isopropyl alcohol (alcholol pads) – allow to dry” (2). There is limited information that iodine may damage the rubber septum of blood culture bottles. We would also recommend each PD centre check with the requirements of their laboratories processing their PD effluent sent for cultures.
For the part of your question on cleaning the sample port of the PD effluent bag, there is some variation in practice. From an informal poll of nurses of the ISPD Nursing Liaison Committee from different countries, cleaning the sample port with an alcohol pad/wipe (isopropyl alcohol 70%) is common practice, one country uses Betadine (povidone-iodine), another chlorhexidine 2% – allow 30 seconds to dry and use aseptic non-touch technique. One recently conducted study from Brazil found that the sample port of the PD effluent bag should be scrubbed with 2% chlorhexidine for at least 5 seconds; if alcohol 70% is used the length of friction should not be inferior to 10 seconds (3). Alcavis (electrolytically produced sodium hypochlorite) is not available in Brazil, therefore not tested in this study; Betadine was also not studied. Other general recommendations to minimize contamination when taking PD effluent samples include: perform hand hygiene and don new, clean gloves before collecting the samples and, for maximal effect, allow the antiseptic used on the sample port to dry.
From the informal poll of nurses from different countries, we found methods for collecting the PD effluent sample for presumed peritonitis varied within countries and between countries; however, we wouldn’t recommend a “clean catch” (pouring from drain bag into a sterile urine cup).
1.Li PK, Szeto CC, Piraino B, de Arteaga J, Fan S, Figueiredo AE, Fish DN, Goffin E, Kim YL, Salzer W, Struijk DG. ISPD peritonitis recommendations: 2016 update on prevention and treatment. Peritoneal Dialysis International. 2016 Sep 1;36(5):481-508.
2. https://www.cdc.gov/antibiotic-use/core-elements/collecting-cultures.html (updated August 2019)
3. Conti A, Katzap RM, Poli‐de‐Figueiredo CE, Pagnussatti V, Figueiredo AE. Disinfection of the peritoneal dialysis bag medication port: Comparison of disinfectant agent and disinfection time. Nephrology. 2018 Sep;23(9):863-6.