Environmental and economic impacts of anaesthesia: A simulation study comparing total intravenous anaesthesia versus sevoflurane for maintenance of anaesthesia in 11 909 adult patients of a Belgian tertiary hospital

Citation:

Van Belleghem F, Rex S, Teunkens A, Vereecke H, Kalmar AF. Environmental and economic impacts of anaesthesia: A simulation study comparing total intravenous anaesthesia versus sevoflurane for maintenance of anaesthesia in 11 909 adult patients of a Belgian tertiary hospital. Eur J Anaesthesiol. 2026;43:567-574. doi:10.1097/EJA.0000000000002342

This study simulated total intravenous anaesthesia versus sevoflurane for maintenance and compared carbon dioxide equivalent emissions and costs. Low-certainty evidence suggests total intravenous anaesthesia has much lower emissions; cost savings are very uncertain. Internal numerical discrepancies and no uncertainty analysis limit exact estimates.

Study at a glance

- Design and setting: Retrospective simulation-based observational cohort study using electronic records from a single Belgian hospital, Sint-Jan Hospital, Bruges, Belgium. Anaesthesia time was defined as start of induction to end of surgery; results were standardised per 1000 procedures.

- Population: 11909 cases were analysed. Inclusion criteria were all general anaesthesia procedures lasting more than 10 min in patients older than 5 years from 1 April to 30 November 2022. Baseline characteristics: 49.9% female, 50.1% male, mean age 55 ± 21 years, anaesthesia time 92 ± 73 min, height 169 ± 12 cm, weight 77 ± 20 kg.

- Exposure and comparator: Each procedure was simulated under four maintenance scenarios with FiO2 50%: sevoflurane with minimal fresh gas flow using automatic gas control with a Flow-I ventilator; sevoflurane with 2 l min-1 fresh gas flow; total intravenous anaesthesia using 1% propofol vials and 6 l fresh gas flow; and total intravenous anaesthesia using 2% propofol vials and 6 l fresh gas flow. All scenarios used induction with propofol 2 mg kg-1 and maintenance with either volatile anaesthetic or propofol 6 mg kg-1 h-1.

- Primary outcome: CO2-equivalent emissions per 1000 procedures: 25593 kg for minimal-flow sevoflurane, 59489 kg for sevoflurane 2 l min-1 fresh gas flow, 1271 kg for total intravenous anaesthesia with 1% propofol, and 812 kg for total intravenous anaesthesia with 2% propofol. The article reported minimal-flow sevoflurane as 26.5 times more CO2e than total intravenous anaesthesia and sevoflurane 2 l min-1 fresh gas flow as 61.8 times more; this suggests lower emissions with total intravenous anaesthesia. No adjusted effect estimate, 95% CI, or p-value reported (low certainty).

- Key secondary outcome: Economic cost per 1000 procedures: €6805 for minimal-flow sevoflurane, €11961 for sevoflurane 2 l min-1 fresh gas flow, €5666 for total intravenous anaesthesia with 1% propofol, and €4264 for total intravenous anaesthesia with 2% propofol. The article reported total intravenous anaesthesia as 16.7 to 52.63% less expensive than sevoflurane, and as costing 36% and 63% of sevoflurane anaesthesia costs with minimal flow and 2 l min-1 fresh gas flow, respectively; exact cost savings are very uncertain. No adjusted effect estimate, 95% CI, or p-value reported (very low certainty).

- Confounding: Patient-level confounding by indication was partly avoided because the same 11909 recorded cases were simulated under each anaesthesia scenario. No causal DAG, covariate-adjusted analysis, propensity score diagnostics, formal validation, or sensitivity analysis was reported; residual concerns depend on fixed assumptions for dosing, fresh gas flow, equipment, vial use, resource use, lifecycle emissions, and local prices.

- Risk of bias and certainty: Overall ROBINS-I risk of bias was Serious. Key concerns were serious bias in selection of the reported result, moderate concerns for confounding, exposure classification, deviations from intended interventions, and outcome measurement, no information for missing data, and low concern for participant selection. Overall GRADE certainty for the primary CO2-equivalent emissions outcome was low; cost outcomes were very low certainty.