Volatile anesthetics are widely recognized as contributors to the carbon footprint produced by the health care industry. A recent study compared the environmental impact of anesthesia practice at two French hospitals – one that elected to use total intravenous anesthesia (TIVA) for the majority of anesthetics and another that adopted a mixed strategy using both TIVA and the volatile anesthetics desflurane and sevoflurane. Based on the results of this study, per anesthetic intervention, which of the following was MOST likely in the TIVA-strategy hospital compared to the mixed-strategy hospital?
- □ (A) Plastic waste was less
- □ (B) Aluminum waste was greater
- □ (C) Carbon dioxide emissions were lower
Anesthetic practice has been shown to be a contributor to global warming, mainly from the use of volatile anesthetics (halogenated agents and nitrous oxide) but also from waste generation and energy use. Desflurane and sevoflurane have been identified as having a global warming potential of 2,720 and 205 times that of carbon dioxide, respectively. Greenhouse gas emissions are not only detrimental to the environment but also have an incremental societal harm that has been financially quantified as the “social cost of carbon.” In a 2021 study, Bressler calculated this cost to be an average of $252 for the emission of 1 ton of carbon dioxide. Moreover, TIVA has been associated with a lower carbon footprint compared with inhaled anesthetic-based techniques. Given their environmental effects, decreasing or even abandoning the use of volatile anesthetics altogether is now being considered.
A recently published retrospective, observational study sought to quantify the carbon footprint of anesthetics performed in adult patients over a two-year period in two multispecialty hospitals in France. One of the centers had made an environmentally driven institutional decision to transition to TIVA-only anesthetics except in compelling emergency cases. The other center allowed a mix of anesthetic techniques, at the discretion of the attending anesthesiologist. The primary study objective was the difference in carbon dioxide emissions per intervention between the two techniques. Secondary objectives were a comparison of social cost, plastic waste, and aluminum utilization between techniques. Both hospitals offer a wide range of noncardiac surgical procedures. The authors collected information including patient age, sex, ASA Physical Status Classification, and duration and type of anesthetic used. They determined the number of general anesthesia cases performed at each center, as well as the amount of sevoflurane, desflurane, and propofol purchased by each central pharmacy. The carbon footprint was expressed in terms of carbon dioxide equivalents (CO2e), which is a universal unit that enables the comparison of the global warming potential of multiple substances as compared with that of carbon dioxide. Life cycle inventories were used to determine the CO2e generated by the use of the aforementioned anesthetic drugs, taking into consideration the emissions generated by the procurement of their raw materials, production, use, and disposal. The carbon footprint of used syringes, power, and wasted propofol was also accounted for in terms of CO2e.
The authors found a substantial difference between the carbon footprint of the hospitals studied. Despite its TIVA-only approach, the TIVA-strategy hospital still generated emissions from sevoflurane and desflurane, calculated at 1.94 tons and 18.76 tons of CO2e, respectively. However, in comparison, the mixed-strategy hospital generated 134.15 tons and 927.83 tons of CO2e from sevoflurane and desflurane, respectively. The authors calculated a carbon footprint of 2.42 kg of CO2e per intervention at the TIVA-strategy hospital versus 48.85 kg of CO2e at the mixed-strategy hospital. The TIVA-strategy hospital generated more plastic waste due to greater syringe use – 64.7 g per intervention compared to 33.3 g in the mixed-strategy hospital; however, the mixed-strategy hospital produced more aluminum waste – 0.1 g versus 6.1 g per intervention. Using the Bressler calculation, the social cost of general anesthesia was calculated at $0.61 versus $12.38 per intervention for the TIVA and mixed-strategy hospitals, respectively.
In conclusion, this study found that a TIVA-only strategy for general anesthesia in adult patients was associated with a more than 20-fold lower carbon footprint compared with a mixed strategy that used both TIVA and volatile anesthetics. The authors extrapolated these figures to suggest that adoption of a TIVA-only strategy in Europe alone could produce a potential decrease of up to $435 million in social cost.
Answer: C