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

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).

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).

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).

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.