Environmental and Economic Impacts of End-tidal Control of Volatile Anesthetics: A Scoping Review and Analysis

This review aimed to assess the environmental and economic impacts of End-tidal Control (ET control) compared to manual clinician administration of inhaled anesthetics.

A scoping literature review was conducted to evaluate the consumption of anesthetic agents when using the Et Control software medical device compared to standard care (manual clinician adjustments) and the associated environmental/economic outcomes. Data were pooled across studies, and standardized mean difference, non-standardized weighted mean difference, and relative reduction in anesthetic agent usage between Et Control and manual adjustments were calculated. Annual reductions in hospital costs and greenhouse gas emissions for a representative 592-bed academic medical center were calculated.

Eight out of the ten identified studies demonstrated that Et Control reduced anesthetic agent usage rates compared to manual administration. Based on the compiled evidence, Et Control results in a mean decrease of anesthetic agent usage by 32.2% for desflurane, 30.1% for isoflurane, and 4.1% for sevoflurane. The annual cost-savings and environmental impact for a large academic medical center using Et Control instead of manual administration is conservatively estimated to be $95,536 ($16,136 per 100 beds), with greenhouse gas emissions reduced by 434,345 kg (73,360 per 100 beds) in CO₂ equivalencies (~100 motor vehicle emissions annually).

Our focused review and analysis indicate that Et Control reduces greenhouse gas emissions of anesthesia practice while also conferring cost-savings. The ability of semi-closed loop anesthesia systems to facilitate low-flow anesthesia warrants the need for future research to understand the full scope of environmental and economic impacts.