Background and Goal of Study: All the volatile anesthetics that are currently used are halogenated compounds and are greenhouse gases. These halogenated anesthetics could have potential significant impact on global warming. They are primarily eliminated through exhalation without being metabolized in the body, and most anesthesia systems transfer these gases as waste directly and unchanged into the atmosphere (1). The use of volatile anesthetics could be reduced by up to 80% to 90% if closed circuit anesthesia were widely used for all patients (2), and to a lesser degree if “low-flow” anesthesia were routinely used. Also, as desflurane has the highest global warming potential (2540) and the longest half life in the atmosphere (14 years), an appropriate drug selection could also reduce both direct and environmental costs. Our study’s objective was to decrease the halogenated anesthetics’ induced pollution by measuring the impact of the implementation of a written protocol on how to use those gases. 
Materials and Methods: We performed a prospective study including a prospective survey of hundred randomly chosen patients that collected the data on which gas was used and what was the hourly consumption before and after the staff education. Using a bottom-up approach, we interrogated the pharmacy on the annual consumption of Sevoflurane and Desflurane before and after the staff education. The levels of consumption of the two gases during the two periods were compared using a parametric t-test. The annual pharmacy consumption before and after was also tested with a t-test. 
Results and Discussion: The initial mean consumption of Sevoflurane and Desflurane were respectively 11ml/h (+/- 4) and 21 ml/h (+/- 12). After the educational training, both consumptions remained at the same level (11±3 and 21±10 respectively, p>0.05). Conversely, the pharmacy consumption of Sevoflurane increased by 13 % while the Desflurane’s one decreased by23 % generating an economy of 5000€/year (p (p<0.05) leading to a reduction by 43 TeqCO2 of our halogenated carbon footprint. The number of cases didn’t vary during the study period. The writing of a protocol and an educational staff significantly reduced our Desflurane consumption. A better choice in the gases indications seems to be accountable for this reduction. The absence of reduction in the hourly consumption may be related to the already low fresh gas flow that was used (the baseline measurement of average fresh gas flow was at 0.86 l/min (+/- 0.23)). 
Conclusion(s): A better understanding of the halogenated gases properties allow to a better utilization and to an important decrease in costs and environmental impact. 


06 / Halogenated anesthetics choice and management can decrease environmental impact and improve the benefits.