The environmental footprint and ecotoxicity of sevoflurane and propofol anaesthesia: a retrospective observational modelling study.

BACKGROUND

General anaesthesia contributes to healthcare-related environmental impacts through anaesthetics with high global warming potential and ecotoxicity. Inhalational anaesthetics have high global warming potential, whereas propofol-based total i.v. anaesthesia (TIVA) has potential for aquatic toxicity. However, the lowest global warming potential fluorinated anaesthetics used, such as sevoflurane, degrade to trifluoroacetic acid (TFA), which is accumulating irreversibly in the environment. We compared the water contamination potential across three anaesthetic strategies: TIVA with propofol, target-controlled inhalational anaesthesia (TCIA) with sevoflurane, and manually optimised low-flow sevoflurane anaesthesia.

METHODS

This retrospective observational modelling study included adult general anaesthesia procedures from three French university hospitals, each using one strategy (TIVA, TCIA, or manual sevoflurane). Anaesthetic consumption was obtained from pharmacy records. Using published physicochemical data and established regulatory concentration thresholds, we calculated estimated instantaneous and long-term water contamination potential for propofol and sevoflurane-derived TFA.

RESULTS

TIVA, TCIA, and manually optimised sevoflurane strategies were used in 10 717, 7207, and 15 461 cases, respectively. In a 10-yr simulation assuming 1000 h of general anaesthesia per year, TFA accumulated linearly to 29-35 million m3 in halogenated strategies, whereas propofol contamination reached a steady plateau after ∼5 yr in the TIVA strategy to 2.6-2.9 million m3 depending on waste management.

CONCLUSIONS

TIVA with propofol generated less water contamination and avoided TFA release while producing locally biodegradable residues. Conversely, sevoflurane-derived TCIA and manual methods led to higher TFA emissions, contributing to its global irreversible accumulation. These findings warrant consideration when minimising the environmental impacts of anaesthetic practises.