Cost‐effectiveness of a transition from volatile anaesthesia to total intravenous anaesthesia to reduce carbon footprint: an economic modelling study

INTRODUCTION: The UK NHS is committed to reaching net zero carbon emissions by 2040. Volatile anaesthetic agents are potent greenhouse gases and alternative intravenous methods exist. We aimed to predict the cost-effectiveness of a transition from volatile anaesthesia to total intravenous anaesthesia to reduce carbon emissions. METHODS: A general anaesthetic for a 40-year-old, 78-kg patient was modelled. Two volatile anaesthetic agents (desflurane and sevoflurane) were compared with propofol-remifentanil total intravenous anaesthesia. Total intravenous anaesthesia with and without processed electroencephalography was modelled. Cost-effectiveness was calculated as the cost per kg carbon dioxide equivalent saved by transition to total intravenous anaesthesia, benchmarked against the UK emission trading scheme carbon permit price of £41. 84 (US54. 90, €47. 28) per tonne carbon dioxide equivalent. RESULTS: Total intravenous anaesthesia was less carbon intensive than sevoflurane and desflurane (2. 0 vs. 9. 8 kg and 209. 2 kg carbon dioxide equivalent, respectively). Total intravenous anaesthesia was more expensive than sevoflurane when processed electroencephalography was used (£13. 03 (US17. 08, €14. 72) vs. £9. 76 (US12. 79, €11. 03) ) but cheaper when it was not (£5. 31 (US6. 95, €6. 00) vs. £9. 76 (US12. 79, €11. 03) ). When processed electroencephalography was used, the incremental cost-effectiveness ratio of transitioning from sevoflurane to total intravenous anaesthesia was £416 (US544, €470) per tonne carbon dioxide equivalent. Total intravenous anaesthesia (with and without processed electroencephalography) was cheaper than desflurane (£18. 94 (US24. 77, €21. 41) ). DISCUSSION: Using our model parameters and the different carbon dioxide emissions and similar cost, transitioning from desflurane anaesthesia to total intravenous anaesthesia is cost-effective. Transitioning from sevoflurane anaesthesia to total intravenous anaesthesia without processed electroencephalography is likely to be cost-effective but is not recommended due to the increased risk of awareness. Transitioning from sevoflurane anaesthesia to total intravenous anaesthesia with processed electroencephalography is unlikely to be cost-effective.