Background & goal of study : Anesthesiologist are in the front line to reduce environmental impact from professional use of inhaled anesthetics. In France, the reduction of the environmental impact of health care is required by law since the Grenelle act (2009). There are different way to reduce our ecological footprint.

Materials & Methods : We performed a search on the ecofriendly practice, datas and clinical trials on PubMed using anaesthetics volatile, atmospheric pollution, ecological footprint gases, fresh gas flow (FGF), inhaled agent as keywords for analysis.

Results & Discussion : All inhaled anesthetics are greenhouse gases (GHG). Atmospheric half-life of Nitrous oxyde (N2O) is 114 years, desflurane 14 years and sevoflurane 1,1 year. Combined to radiative properties their 100 years global warming potential (GWP100), which determine their carbon footprint at 100 years, is 2540 for desflurane, 298 for N2O and 130 for sevoflurane. The GWP100 of carbon dioxide (CO2) is 1. Medical N2O is also an ozone-depleting gas. It represents 0,5% of global human GHG emissions. When used with halogenated agents, N2O is responsible of more than 50% of ecological impact. The global carbon footprint of halogenated agents is estimated from measurements by Vollmer (1) at 3.1 +/- 0.6 million metric tonnes of carbon dioxide equivalents in 2014 of which near 80% comes from desflurane. There are different ways to improve our practice. First by manually reducing the FGF. Guthinger (2) calculated an halogenated consumption decrease of 40% with FGF reduction from 1,24L/min (±0,74) to 1L/min. Second by using a Target Controlled Inhalation (TCI) mode. Tay & al (3) demonstrated a reduction of CO2 emission by 44% with this mode. Third, regarding the different environmental costs of inhaled agents, users should consider a well-reasoned use of anesthetic drugs with an ecofriendly approach. Moreover, inhaled anesthetics are eliminated with low metabolization directly and unchanged into the atmosphere. System of recovery and reuse anesthesics gases is available for commercial use in Canada (Deltasorb® technology). It’s a canister placed in the scavenging system which adsorb the anesthetic, later collecte, then retrieved and purified at a company facility. 

Conclusion : Ecological footprint of inhaled anesthetics should be considered in our professional practice.

References :
Vollmer , Geophys Res Lett, 2015
Guthinger, Ann Fr Anesth Reanim, 2014
Tay, Anaesth Intensive Care, 2013

02 / Operating room greenhouse gas release reduction