Financial and environmental costs of manual versus automated control of end-tidal gas concentrations

• Published in: Anaesthesia and intensive care Vol. 41; no. 1; pp. 95 - 101
• Main Authors: Tay, S, Weinberg, L, Peyton, P, Story, D, Briedis, J
• Format: Journal Article
• Language: English
• Published: United States Sage Publications Ltd. (UK) 01.01.2013; Sage Publications Ltd
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Air pollution; Anesthesia; Anesthesia, General - economics; Anesthesia, General - instrumentation; Anesthetics, Inhalation - administration & dosage; Anesthetics, Inhalation - economics; Automation; Carbon Dioxide - chemistry; Child; Child, Preschool; Desflurane; Drug Costs; Economic aspects; Female; Global Warming; Greenhouse Effect - economics; Greenhouse Effect - prevention & control; Hospitals, University; Humans; Infant; Isoflurane - administration & dosage; Isoflurane - analogs & derivatives; Isoflurane - economics; Male; Methyl Ethers - administration & dosage; Methyl Ethers - economics; Middle Aged; Natural gas; Pollution control; Prospective Studies; Sevoflurane; Technology application; Young Adult
• ISSN: 0310-057X; 1448-0271
• DOI: 10.1177/0310057x1304100116

Emerging technologies that reduce the economic and environmental costs of anaesthesia have had limited assessment. We hypothesised that automated control of end-tidal gases, a new feature in anaesthesia machines, will consistently reduce volatile agent consumption cost and greenhouse gas emissions. As part of the planned replacement of anaesthesia machines in a tertiary hospital, we performed a prospective before and after study comparing the cost and greenhouse gas emissions of isoflurane, sevoflurane and desflurane when using manual versus automated control of end-tidal gases. We analysed 3675 general anaesthesia cases with inhalational agents: 1865 using manual control and 1810 using automated control. Volatile agent cost was $18.87/hour using manual control and $13.82/hour using automated control: mean decrease $5.05/hour (95% confidence interval: $0.88-9.22/hour, P=0.0243). The 100-year global warming potential decreased from 23.2 kg/hour of carbon dioxide equivalents to 13.0 kg/hour: mean decrease 10.2 kg/hour (95% confidence interval: 2.7-17.7 kg/hour, P=0.0179). Automated control reduced costs by 27%. Greenhouse gas emissions decreased by 44%, a greater than expected decrease facilitated by a proportional reduction in desflurane use. Automated control of end-tidal gases increases participation in low flow anaesthesia with economic and environmental benefits.