CARbon Impact of aNesthesic Gas

Study Overview
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Brief Summary
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Assessing the impact of anesthesia practice on global warming and carbon footprint becomes part of the standard of care and is growing concern within the anesthesia community. Global Warming Potential (GWP) is a measure of how much a given mass of greenhouse gas contributes to global warming over a specified time period. Inhaled anesthetics have various GWP20: 349 for sevoflurane and 3714 for desflurane. However, GWP20 and CDE20 alone are not sufficient to evaluate the environmental impact of anesthetic gases. Other parameters must be included in the analysis: fresh gas flow (FGF), carrier gas (air, O2, N2O) and potency of the anesthetic gas. Unfortunately, the majority of trials did not fully consider the FGF reduction and the fact that desflurane can be administered with new closed or very low-flow anesthesia circuits as opposed as the recommended 2L/min that must be used for sevoflurane according to its monography in Canada. Most of the calculations were made on a purely theoretical approach that could be different from actual measurements based on a strictly monitored anesthesia practice. When continuous and accurate gas monitoring and analysis is used as recommended nowadays, the use of closed or semi-closed-circuit anesthesia with very low FGF might allow for a reduction of more than 80% of the anesthetic gas administration and its consequent pollution. By properly monitoring the anesthesia depth and analgesia adequacy, the investigators can reduce the gas consumption. The proposed study will aim at determining whether with the help of high-quality monitoring (BIS and NOL) and high-end ventilators that allow minimal fresh gas flow, the use of desflurane remains more polluting than sevoflurane.

Official Title
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CARbon Impact of aNesthesic Gas - A Carbon Footprint Comparison of Sevoflurane and Desflurane in an Optimized Fresh Gas Flow Protocol

Conditions
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Gas; Inhalation, Anesthesia

Intervention / Treatment
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* Other: Pollution


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA 1-3 patients, laparoscopic general, gynecological or urologic surgery requiring general anesthesia without additional regional anesthesia technique fully consented, BMI < 40, age > 18yo, Exclusion Criteria: post-operative need for a neuraxial or regional analgesic technique history of active coronary artery disease serious cardiac arrhythmia (including atrial fibrillation) history of substance abuse chronic use of psychotropic and/or opioid drugs history of psychiatric diseases with the need of medication history of refractory PONV allergy or contra-indication to any drug used in the study protocol refusal of the patient for participation in the study

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Desflurane<br>desflurane administration based on a BIS index kept between 40-60 and with use of the semi-closed circuit of the Draeger A500 ventilator and its econometer for an optimized fresh gas flow as low as the O2 consumption allows | Other: Pollution<br>* CO2 equivalent productions related to anesthetic gases use during general anesthesia for laparoscopic surgery<br>|
| Sevoflurane<br>sevoflurane administration based on a BIS kept between 40-60 and with use of the semi-closed circuit of the Draeger A500 ventilator with a fixed fresh gas flow of 2L/min as requested in the gas monography | Other: Pollution<br>* CO2 equivalent productions related to anesthetic gases use during general anesthesia for laparoscopic surgery<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| CO2 equivalent of volatile inhaled anesthesic gases use in grams | To compare total volatile inhaled anesthetics consumption in CO2 equivalent (grams) per hour during anesthesia for laparoscopic surgery between two groups: Group D for Desflurane and group S for Sevoflurane | From intubation to end of surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total volatile inhalated anesthesics consumption in mL | To compare the total volatile inhaled anesthetics consumption in mL, mL/h and mL/kg/h during anesthesia for laparoscopic surgery between desflurane and sevoflurane | From intubation to end of surgery | 
| Cost in dollars | To compare the total cost of volatile inhalated anesthesics (mL of gaz x $/mL of gaz) for each group | From intubation to end of surgery | 
| Extubation time in minutes | To compare the extubation time | From stopping anesthesics gases to extubation | 
| Recovery room time in minutes | To compare the time spent in the recovery room | From end of surgery to 240minutes post-surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Desflurane, Sevoflurane, Fresh gas flow, Environment