L HUANG1,2, E RAMAS1, P PRASAD3, J CATANIA4, P MEADE4, E BUTLER3, LP MCMAHON1,2
1Department of Renal Medicine, Eastern Health, Box Hill, Victoria; 2Department of Medicine, Eastern Health Clinical School, Box Hill, Victoria; 3Department of Pharmacy, Eastern Health, Box Hill, Victoria; 4Department of Pathology and Microbiology, Eastern Health, Box Hill, Victoria
Aim: To compare the sterility of antibiotic-loaded peritoneal dialysis fluid (PDF) admixed using sterile-technique versus non-touch aseptic technique (NTAT).
Background: There is a paucity of data on the sterility of PDF after drug admixture. ISPD guidelines suggest using sterile-technique when admixing IP antibiotics, however the degree of sterility remain unclear. This issue is most pertinent when preparing take-home PDF for the outpatient treatment of peritonitis.
Methods: Groups of n=8 PDF (1.5% Dianeal or Extraneal) were admixed with antibiotics (ceftazidime and vancomycin, 1g/L) or 20mL saline, either by a pharmacist using sterile-technique in a sterile-suite (sterile gloves, filtered air, laminar flow hood), or a nurse in a clinical room utilising NTAT. PDF inoculated with 1×106 CFU/L of Coagulase-negative Staphylococcus (CNS, S. epidermidis or S. haemolyticus) with or without antibiotics, served as positive controls. Admixed PDF were left in room temperature for 72-hours, before being cultured using the BacT/ALERT system. A positive culture by day-5 constitutes a contamination. Differences in proportion of contamination between groups were assessed by the Χ2 test.
Results: Eighty PDF-bags completed microbiological testing. PDF sterility was maintained in all bags, independent of technique (sterile-technique vs. NTAT), type of PDF (Dianeal vs. Extraneal), or whether antibiotics were admixed (antibiotics vs. saline). Of the positive controls, CNS inoculated bags without antibiotics were all culture positive (8/8 for both S. epidermidis and S. haemolyticus); however, when inoculated into antibiotic loaded-PDF, only S. haemolyticus remained culture-positive (Χ2,df=27.67, 3, p<0.0001).
Conclusions: PDF sterility can be maintained using non-touch aseptic technique, for up to 3-days at room temperature. Currently, there is insufficient evidence to utilise a sterile-suite when admixing take-home PDF.