Consequences of microbial contamination during extended intravenous therapy using inline filters.
A study was conducted to determine: (1) the effectiveness of 0.22-mum and 0.45-mum pore size membrane filters in retaining microorganisms over a period of 72 hours of intravenous fluid administration; (2) the growth and multiplication characteristics of microorganisms retained on the filter; and (3) the possibility of pyrogens being released by microorganisms trapped on the filter.  Lactated Ringer's injection was used as the i.v. solution. The 0.45-mum filter was found to be effective in retaining all microorganisms studied for at least 6 hours. However, Esherichia coli and Pseudomomas aeruginosa began passing through the 0.45-mum filter between 6 and 8 hours after seeding.  All other microorganisms (Candida albicans, Citrobacter freundii, Klebsiella pneumoniae, Staphyloccus aureus) were retained for at least 72 hours.  None of the microorganisms passed through the 0.22-mum filter during the 72-hour study period.  With viable microorganisms on the filter for 72 hours, no detectable endotoxins or pyrogens were found in the filtrates as examined by the limulus and rabbit tests.
D000818:Animals; D004340:Drug Contamination / Q000517:prevention & control; D004926:Escherichia coli / Q000254:growth & development; D005374:Filtration; D007275:Injections, Intravenous; D004364:Pharmaceutical Preparations / Q000032:analysis; D011550:Pseudomonas aeruginosa / Q000254:growth & development; D011749:Pyrogens / Q000032:analysis; D011817:Rabbits; D013242:Sterilization
D004364:Pharmaceutical Preparations; D011749:Pyrogens