Is it time to stop using desflurane?

Desflurane has a carbon equivalence 20 times greater than sevoflurane. This article discusses alternative anaesthetic techniques, including sevoflurane, xenon, total intravenous anaesthesia and regional techniques, and methods of reducing venting of gases, which might lower the environmental impact of anaesthesia.

[Climate footprint of halogenated inhalation anesthetics]. / Klimateffekterna från anestesin kan minska.

This study estimated the climate footprint of halogenated inhalation anesthetics in Sweden and estimated effects of a decreased use of these compounds. We collected data on sales of desflurane, sevoflurane and isoflurane in Sweden during 2017 and calculated the mass of CO2 equivalents (CO2e) using Global Warming Potential data over 100 years for the compounds. Inhalation anesthetics contributed by 5000 tons of CO2e which corresponds to 0.005 percent of the Swedish climate footprint. By replacing desflurane with sevoflurane the footprint can be reduced by 73 percent. By replacing sevoflurane with intravenous propofol the climate effect can be reduced further by at least 2 orders of magnitude.

Preparation of anaesthesia workstation for trigger-free anaesthesia: An observational laboratory study.

BACKGROUND: Trigger-free anaesthesia is required for patients who are susceptible to malignant hyperthermia. Therefore, all trace of volatile anaesthetics should be removed from anaesthetic machines before induction of anaesthesia. Because the washout procedure is time consuming, activated charcoal filters have been introduced, but never tested under minimal flow conditions. OBJECTIVE: To investigate performance of activated charcoal filters during long duration (24 h) simulated ventilation. DESIGN: A bench study. SETTING: A Primus anaesthesia machine (Dräger) was contaminated with either 4% sevoflurane or 8% desflurane by ventilating a test lung for 90 min. The machine was briefly flushed according to manufacturer instructions, activated charcoal filters were inserted and a test lung was ventilated in a 24 h test. Trace gas concentrations were measured using a closed gas loop high-resolution ion mobility spectrometer with gas chromatographic preseparation. During the experiment reduced fresh gas flows were tested. At the end of each experiment the activated charcoal filters were removed and the machine was set to standby for 10 min to test for residual contamination within the circuit. The activated charcoal filters were reconnected into the circuit to test their ability to continue removing volatile anaesthetics (functional test) from the gas. Control experiments were conducted without activated charcoal filters. MAIN OUTCOME MEASURES: Absolute concentrations of desflurane and sevoflurane. RESULTS: The concentration of volatile anaesthetics dropped to less than 5 ppm (parts per million) following insertion of activated charcoal filters. In the desflurane experiments at least 1 l min FGF was needed to keep the concentration below an acceptable level (<5 ppm): 0.5 l min fresh gas flow was required in sevoflurane experiments. While activated charcoal filters in the sevoflurane tests passed the functional test after 24 h, activated charcoal filters in the desflurane tests failed. CONCLUSION: Activated charcoal filters meet the requirements for trigger-free low flow (1 l min) ventilation over 24 h. Minimal flow (0.5 l min) ventilation may be possible for sevoflurane contaminated machines.