Analysis of waste generation and environmental impact of a multi-dose iodinated contrast media injection system in an emergency radiology department.

INTRODUCTION

The introduction of automatic multi-dose injectors has revolutionised contrast media management in Computed Tomography (CT) imaging, affecting both workflow efficiency and waste production. However, there is limited evidence regarding their environmental performance in high-turnover emergency settings. This study provides a quantitative assessment of contrast media waste and of materials associated with a multi-dose injector in an emergency radiology department.

METHODS

All iodinated contrast media (ICM) administrations for CT examinations performed between May 2023 and April 2024 were retrospectively analysed using data extracted from the injector's digital reports. For each examination, administered volume, unused ICM, number of vials, and associated plastic, glass, and paper waste were recorded and aggregated monthly.

RESULTS

A total of 4,418 contrast-enhanced CT scans were reviewed. Overall, 1,362 vials of ICM were used, corresponding to 600.9 L loaded and 456.2 L administered. The average injected dose was 103.3 mL per scan (median 110; IQR 70-127), while 144.7 L (31.7%) of ICM were wasted, equivalent to 290 vials and 53.1 kg of iodine. Additionally, 411 daily injector kits and 4,803 patient lines contributed to the total waste stream, mainly composed of plastic and glass components.

DISCUSSION: Most ICM waste derived from residual volumes in daily injection kits discarded at the end of each shift, rather than from patient administration. High variability in patient flow and fixed daily kit usage appear to be the determining factors of environmental impact. These findings indicate the need for operational adjustments, such as the use of ICM vials of different volumes to reduce waste at the end of the day and the implementation of containers for recycling ICMs, disposable devices and packaging.

CONCLUSION

Contrast media waste remains a relevant source of environmental impact in emergency CT operations. Reducing residual ICM and optimising injector use could significantly improve sustainability and resource efficiency. Radiographers could play an important role in monitoring injector usage, promoting awareness, and implementing waste reduction strategies within clinical workflows.