Venous thromboembolism (VTE) account for 7% of all deaths in Australian hospitals.1 Two ways to avoid VTE include chemical prophylaxis and single-use mechanical calf compressors. Northern Sydney Local Health District (NSLHD) is reviewing its use of compressors to reduce healthcare-associated waste, as part of its mission to reach net zero emissions by 2035.
In intensive care units (ICUs), these approaches are typically used in combination. However, there is strong evidence to suggest that mechanical calf compressors do not provide any additional benefit in reducing VTE when patients are already receiving chemical prophylaxis.2, 3 The aim of this project was to reduce unnecessary use of calf compressors in Royal North Shore Hospital (RNSH) ICU. We conducted a before-and-after single-site study to assess use of calf-compressors before and after delivery of staff education.
Facilitating behaviour change through education
The study commenced with a three-month audit period to assess baseline patterns of use. Nursing staff recorded use of calf compressors via a logbook, and ordering patterns were monitored. Following this, we undertook an intervention period to facilitate behaviour change. Education was provided for nursing and medical staff on the effectiveness of compressors and the waste being generated locally. Face-to-face meetings, a colour-coded decision-making tool and posters prompted staff to consider their usage. To limit physical access to calf compressors, we relocated them from readily accessible locations to storerooms.
We encouraged medical staff not to prescribe calf compressors unless the patient had a known contraindication to chemical prophylaxis. Another three-month audit period followed the intervention, once again monitoring use via logbook and ordering patterns. We assessed appropriateness of use pre- and post-education using ICU VTE management guidelines. An estimate of the embodied carbon for a single pair of calf compressors was calculated by isolating individual components, weighing these and multiplying them by publicly available manufacturing emissions factors.4
Unnecessary use of calf-compressors reduced to 10%
Comparisons of pre- and post-education audits noted a decrease from 57% unnecessary calf-compressor use to just 10%. A single pair of calf compressors including their plastic packaging was estimated to contribute 0.43kgCO2e. The decrease in unnecessary use from pre to post-education represented a 12.96kgCO2e saving, or a minimum annual saving of 51.84 kgCO2e. We also compared packaging waste between the pre- and post-education period, with a saving of 3.7 kg identified, or a projected annual saving of 15 kg.
The intervention resulted in monetary saving for the district through decreased use and re-ordering of calf compressors. A saving of $523.80 was calculated because of the education provided, with 11 fewer boxes ordered during the post-education period than pre-education. This equates to a minimum saving of $7,682 annually. Next steps include:
- disseminate research findings at national and international conferences
- publish manuscript in a peer reviewed journal
- engage with sustainability representatives across other health districts to discuss the scalability of this project in other ICUs.
The main difficulty this project faced was engaging already time-poor nursing staff with an additional administrative task. Consultation undertaken prior to baseline audits did lead to a reduction in completer burden, however it is likely this impacted the baseline dataset nonetheless.
A staff survey following education indicated that 60% of staff found the visual decision-making tool the most useful aspect of training provided. The decision-making tool was created in line with RNSH ICU specific policies; therefore, any replication of the project would require these to be realigned for their new context.
This project was part of the NSLHD Net Zero Leads Program.
References
- Access Economics Pty Ltd for the Australia and New Zealand working party on the management and prevention of venous thromboembolism. The burden of venous thromboembolism in Australia, 1 May 2008. Access Economics Pty Ltd; 2008.
- Arabi YM, Al-Hameed F, Burns KEA, et al. Adjunctive Intermittent Pneumatic Compression for Venous Thromboprophylaxis. N Engl J Med. 2019;380(14):1305-1315. doi:10.1056/NEJMoa1816150
- Wang Y, Huang D, Wang M, Liang Z. Can Intermittent Pneumatic Compression Reduce the Incidence of Venous Thrombosis in Critically Ill Patients: A Systematic Review and Meta-Analysis. Clin Appl Thromb Hemost. 2020;26:1076029620913942. doi:10.1177/1076029620913942
- Circular Ecology. Embodied Carbon – The ICE Database. Worcestershire; 2019. [cited Jul 2024].
