Microbiological Risks Quantified During IV Drug Delivery System Preparation
9 October 2011E. Tidswell Senior Director, Research Sterility
Baxter Healthcare Corporation, USA
Vascular access of patients by peripheral and central venous catheters for the delivery of sterile, aseptically manufactured and admixed parenterals is commonly regarded as one of the major causes of blood stream infections. Evaluation and management of the risks of microbial infection originating from the administration of aseptically manufactured and especially admixed therapies remain imperative to reduce patient infection risks. The hospital environment is especially complex, dynamic with a diverse range of sources and vectors of microorganisms with the potential to cause infection. If microorganisms access IV solutions adverse consequences for the patient are rapid; data are presented illustrating the tracking of contamination throughout a IV administration system. Analysis and interpretation of the available, reported hospital data to evaluate infection rates are constrained by the variability and uncertainty associated with each individual administration scenario. Moreover, clinical trials quantifying infection risk are constrained by their practicality, cost, and the control of the exacting requisite trial criteria. Furthermore, it is ethically inappropriate to systematically conduct clinical evaluations incorporating conditions that do not favor the best possible patient outcomes. Quantitative risk modeling (QRM) is a unique tool offering an alternative and affective means of assessing design and clinical use in the context of the clinical environment on medical device and combinatorial therapy infection rates. The generation of QRMs and the evaluation of manual admixing IV bags for use in IV administration sets upon patient infection rates are described. Manual admixing of IV bags was assessed for the opportunity and risk of microbial ingress accessing across the sterile barrier during clinical preparation and contaminating the IV solution. The risk of microbial contamination was evaluated under (a) ISO 5 compounding conditions adopting ideal aseptic technique (in compliance with USP <797>) and (b) realistic worst-case point-of-care conditions (typically found in hospital wards). The evaluation estimated contamination rates ranged from <2.2 ppm (2.2 contaminated units in every million uses) to 2.9% (29 contaminated units in every 1000 uses), contingent upon the clinical environment. QRM permits the swift probabilistic evaluation of contamination rates providing the healthcare professional with data to make an informed choice of medical devices and a preparation strategy in their precise clinical context, reducing hospital acquired infections for optimal clinical patient outcomes.
KEYWORDS: Quantitative risk modeling, IV bags, IV administration of parenterals, Hospital-acquired infections.