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.