Guidelines for reducing the environmental impact of general anaesthesia

The environmental impacts of anesthesia

PURPOSE OF REVIEW

The healthcare sector has a substantial environmental footprint, and the delivery of anesthesia contributes significantly. Inhaled anesthetics themselves are potent greenhouse gases, unused intravenous medication exert toxic effects on the environment, and the increasing reliance on single-use devices has led to an ever-growing amount of solid waste produced in operating rooms. This review discusses many of these environmental impacts and suggests practices to mitigate the environmental footprint of anesthetic practice.

RECENT FINDINGS

The choice of anesthesia maintenance has significant environmental implications, with nitrous oxide and desflurane having the highest carbon footprint of all anesthetic agents. Using low fresh gas flows and supplementing or replacing inhalational agents with propofol leads to a significant reduction in emissions. Many intravenous anesthetic agents pose a risk of environmental toxicity, and efforts should be made to decrease medication waste and ensure appropriate disposal of unused medications to minimize their environmental impacts. Additionally, consideration should be given to replacing single-use devices in the operating rooms with reusable alternatives that are often both environmentally and economically superior. And solid waste generated in the operating room should be segregated thoughtfully, as processing regulated medical waste is a highly energy-intensive process.

SUMMARY

Significant opportunities exist to improve the environmental footprint of anesthesia practice, and with the rapidly worsening climate crisis, the importance of implementing changes is greater than ever.

Reducing the carbon footprint of general anaesthesia: a comparison of total intravenous anaesthesia vs. a mixed anaesthetic strategy in 47,157 adult patients

Global warming is a major public health concern. Volatile anaesthetics are greenhouse gases that increase the carbon footprint of healthcare. Modelling studies indicate that total intravenous anaesthesia is less carbon intensive than volatile anaesthesia, with equivalent quality of care. In this observational study, we aimed to apply the findings of previous modelling studies to compare the carbon footprint per general anaesthetic of an exclusive TIVA strategy vs. a mixed TIVA-volatile strategy. This comparative retrospective study was conducted over 2 years in two French hospitals, one using total intravenous anaesthesia only and one using a mixed strategy including both intravenous and inhalation anaesthetic techniques. Based on pharmacy procurement records, the quantity of anaesthetic sedative drugs was converted to carbon dioxide equivalents. The primary outcome was the difference in carbon footprint of hypnotic drugs per intervention between the two strategies. From 1 January 2021 to 31 December 2022, 25,137 patients received general anaesthesia in the hospital using the total intravenous anaesthesia strategy and 22,020 in the hospital using the mixed strategy. The carbon dioxide equivalent footprint of hypnotic drugs per intervention in the hospital using the total intravenous anaesthesia strategy was 20 times lower than in the hospital using the mixed strategy (emissions of 2.42 kg vs. 48.85 kg carbon dioxide equivalent per intervention, respectively). The total intravenous anaesthesia strategy significantly reduces the carbon footprint of hypnotic drugs in general anaesthesia in adult patients compared with a mixed strategy. Further research is warranted to assess the risk-benefit ratio of the widespread adoption of total intravenous anaesthesia.