Managing Fresh Gas Flow to Reduce Environmental Contamination

Abstract

Anesthetic drugs have the potential to contribute to global warming. There is some debate about the overall impact of anesthetic drugs relative to carbon dioxide, but there is no question that practice patterns can limit the degree of environmental contamination. In particular, careful attention to managing fresh gas flow can use anesthetic drugs more efficiently--reducing waste while achieving the same effect on the patient. The environmental impact of a single case may be minimal, but when compounded over an entire career, the manner in which fresh gas flow is managed by each individual practitioner can make a significant difference in the volume of anesthetic gases released into the atmosphere. The maintenance phase of anesthesia is the best opportunity to reduce fresh gas flow because circuit gas concentrations are relatively stable and it is often the longest phase of the procedure. There are, however, methods for managing fresh gas flow during induction and emergence that can reduce the amount of wasted anesthetic vapor. This article provides background information and discusses strategies for managing fresh gas flow during each phase of anesthesia with the goal of reducing waste when using a circle anesthesia system. Monitoring oxygen and anesthetic gas concentrations is essential to implementing these strategies safely and effectively. Future technological advances in anesthetic delivery systems are needed to make it less challenging to manage fresh gas flow.

Reducing Wastage of Inhalation Anesthetics Using Real-time Decision Support to Notify of Excessive Fresh Gas Flow

“…§ Totally 2,071 cases. Cases less than 10 min long (26) and with no inhalation agents (200) were excluded. Nair et al Two-sample t test with unequal variances was used to compare mean FGF between pairs of phases.…”

“…Most new anesthesia machines are capable of measuring and exporting FGF data to an AIMS. In a recent article that discussed strategies of managing FGF, Feldman 26 highlights emerging technologies related to anesthesia delivery system, which makes it possible to use low FGFs in closed-circuit anesthesia. However, such technologies are expensive and require specialized anesthesia machines.…”

Low and minimal flow anesthesia: Angels dancing on the point of a needle

“…[5] In 2012, Anesthesia and Analgesia revisited the potential environmental impact of inhalational anesthetics with a series of articles and editorials devoted to the subject. [5–8] The drumbeat of climate change has led to increasing calls for anesthetists to consider the “environmental ethics” of their anesthetic choices as a part of perioperative planning. [5]…”

Wash-in and wash-out of sevoflurane in a test-lung model: A comparison between Aisys and FLOW-i

“…Reducing the amount of anaesthetic agent consumed is of interest not only for reducing cost, but also for reducing environmental burden. The merits of reducing flow must not overrule safety, by maintaining adequate oxygen content in the circle, and avoiding hypoxic gas mixture, inadequate anaesthesia control and too light anaesthesia with risk for awareness ii, iii . Increasing and decreasing the circle system anaesthetic concentration during low and minimal flow anaesthesia calls for knowledge around the technique and kinetics of the anaesthetic gas used.…”