Which carbon footprint for my ICU? Benchmark, hot spots and perspectives

Abstract

Background: The purpose of this study was to identify the main greenhouse gas (GHG) emitting activities or products among the medical devices (MD) and medicines used in a polyvalent Intensive Care Unit (ICU).

Methods: A pragmatic eco-audit was conducted in a 21-beds polyvalent ICU, in Saint-Brieuc, Bretagne, France. It consisted of estimating GHG emissions of products or activities, considering process-based life cycle analysis (LCA), economic input-output analysis (EIO) and hybrid-LCA. Results were expressed as Carbon Dioxide Equivalent (CO₂e) emissions per patient-day considering each medication and MD (including personal protective equipment).

Results: With remaining uncertainty, GHG emissions were estimated at 61.1 kgCO₂e per patient-day. Two hundred and two individual MD were used per patient-day, equivalent to 5.1 kgCO₂e per patient-day (process-based LCA). Gloves accounted for the main part of kgCO₂e emissions (representing 1.8 kgCO₂e per patient-day). Then, syringes (1.1 kgCO₂e per patient-day), perfusion tubings (1.0 per patient-day) and gauze pads (0.4 kgCO₂e per patient-day) were the most important sources of MD related GHG emissions. Forty-seven individual medicines were used per patient-day. Most consumed medications were sterile water for injection, propofol, and sodium chlorure. The GHG emissions of medications were estimated with EIO-LCA at 21.5 kgCO₂e per patient-day, mostly due to injectable medicines (15.3 kgCO₂e per patient-day).

Conclusion: Upcoming studies focusing on actions on these particular hot spots would be of interest in order to significantly decrease GHG emissions but also to increase resilience of critical care.

Keywords: Critical care; Global warming; Life cycle assessment.

Fig. 1

GHG emissions distribution by category (process based LCA for medical devices, EIO-analysis for medicine and hybrid LCA for other categories)

Fig. 2

Consumption of the most used medications. Datas are expressed as units per patient-day. *”IV solutions” includes Water for injection (IV) (10–20 mL), Glucose 5% (IV) (10–1000 mL), and Sodium Chlorure 0,9% (IV) (10–1000 mL)

Fig. 3

Consumption and GHG emissions of the most used medical devices. Datas are expressed as units per patient-day for consumption, and as kgCO2e per patient-day for GHG emissions