Drug waste of ready-to-administer syringes in the intensive care unit: Aseptically prepared syringes versus prefilled sterilized syringes

Abstract

Background: The availability of ready-to-administer (RTA) syringes for intravenous (IV) drugs facilitates rapid and safe administration in emergency and intensive care situations. Hospital pharmacies can prepare RTA syringes through aseptic batchwise filling. Due to excess production of these RTA syringes for sufficient availability for patient care and their limited (microbiological) shelf-life, waste is unavoidable, which contributes to environmental pollution. RTA prefilled sterilized syringes (PFSSs) have much longer shelf-lives than aseptically prepared RTA syringes and might contribute to reducing drug waste.

Aim: This study aimed to evaluate the difference in drug waste between RTA syringes that were prepared through aseptic batchwise filling and RTA PFSSs in the Intensive Care Unit (ICU).

Methods: We measured drug waste of RTA syringes over an 8-year time period from August 2015 to May 2023 in the 32-bed ICU of the University Medical Center Utrecht. We distinguished between RTA syringes prepared through aseptic batchwise filling by our hospital pharmacy ("RTA aseptic syringes", shelf-life of 31 days) and RTA PFSSs (shelf-life of 18 months). An intervention group of three drug products that were replaced by PFSSs was compared to a control group of five drug products that were not replaced by PFSSs during the study period. We then defined four different periods within the total study period, based on quarantine time of the RTA aseptic syringes and time of PFSS introduction: 1) no quarantine, 2) 3-day quarantine, 3) 7-day quarantine and 4) PFSS introduction. Our primary endpoint was the number of RTA syringes that was wasted, expressed as the percentage of the total number of syringes dispensed to the ICU in each of these four periods. We used a Kruskall-Wallis test to test if waste percentages differed between time periods in the control and intervention groups, with a post-hoc Dunn's test for pairwise comparisons. Furthermore, we applied two interrupted time series (ITS) analyses to visualize and test the effect of introducing different quarantine times and the PFSSs on waste percentage.

Results: Introduction of PFSSs significantly decreased drug waste of RTA syringes irrespective of drug type in the intervention group, from 31% during the 7-day quarantine period to 5% after introduction of the PFSS (p<0.001). The control group showed no significant decrease in drug waste over the same time periods (from 20% to 16%; p=0.726). We observed a significant difference in the total drug waste of RTA aseptic syringes between time periods, which may be attributed to the implementation of different quality control quarantine procedures. The ITS model of the intervention group showed a direct decrease of 17.7% in waste percentage after the introduction of PFSSs (p=0.083).

Conclusion: Drug waste of RTA syringes for the ICU can be significantly decreased by introducing PFSSs, supporting hospitals to enhance environmental sustainability. Furthermore, the waste percentage of RTA syringes prepared through aseptic batchwise filling is significantly impacted by duration of quarantine time.

Keywords: Drug waste; Environmental sustainability; Intensive care unit; Prefilled sterilized syringes; Ready-to-administer syringes.