Validation of Waste Anaesthetic Gas Exposure Limits When Using a Closed Vaporizer Filling System: A Laboratory-Based Study

Abstract

Introduction: It is desirable to minimise exposure of personnel to halogenated inhaled anaesthetics in the operating room to avoid deleterious short-term and long-term health effects. The objective of this study was to determine whether, while filling anaesthetic vaporizers with sevoflurane using AbbVie's closed vaporizer filling system (Quik-Fil TM), concentrations of sevoflurane in ambient air remained at or below recommended levels when measured at different operator heights. Methods: Nine filling runs were conducted, with measurement heights of 95, 130, 140, 150, 160, and 185 cm. Within each 15-min run, five vaporizers were sequentially filled from bottles of sevoflurane with the closed valving system. Ambient-air sevoflurane concentration in the breathing zone was continuously measured once per second by using a MIRAN SapphIRe 205BXL portable ambient air analyser. Results: The use of the closed filling system maintained a level of waste anaesthetic gas exposure that was well below (mean, 0.10 ppm; maximum, 0.16 ppm) the recommended shortterm value of 20 ppm average for 15 min provided by the Swedish Work Environment Authority and also fell below the US limit of a time-weighted average of 2 ppm provided by the National Institute for Occupational Safety and Health. Exposure to sevoflurane appeared to be independent of the height at which the measurement was made. Conclusions: The presence of sevoflurane in the work environment while using the closed filling system maintains a level of waste anaesthetic gas exposure well below the recommended levels at all tested operator heights.

Environmental and Occupational Considerations of Anesthesia: A Narrative Review and Update

“… 67 This closed filling system also maintained sevoflurane exposure (0.10 ppm) in the operator breathing zone that was well below the recommended maximum levels (2 ppm for 1 hour or 20 ppm for 15 minutes) and may help minimize occupational exposure. 68 …”

“…67 This closed filling system also maintained sevoflurane exposure (0.10 ppm) in the operator breathing zone that was well below the recommended maximum levels (2 ppm for 1 hour or 20 ppm for 15 minutes) and may help minimize occupational exposure. 68 Total Intravenous Anesthesia Based on the issues associated with volatile anesthetics discussed above, total intravenous anesthesia (TIVA) may be considered as an alternative to volatile/inhaled anesthetics. 13,42,51,57 By its nature, TIVA is not associated with the risks of occupational exposure inherent to volatile anesthetic gases; however, TIVA is not entirely devoid of potential negative environmental effects and the total environmental impact of TIVA must be taken into account.…”

Occupational Exposure to Halogenated Anaesthetic Gases in Hospitals: A Systematic Review of Methods and Techniques to Assess Air Concentration Levels

“…To characterize the risk resulting from occupational exposure to WAGs, it is important to compare the results of exposure monitoring with occupational exposure limits. For volatile anaesthetics, the U.S. National Institute of Occupational Safety and Health (NIOSH) recommended exposure limit (REL) was set at 2 ppm related to a reference period of 1 h [27]. This limit value, published in 1977, is based on the ALARA (As Low As Reasonably Achievable) principle and on the assimilation of the different toxicological profiles to that of enflurane.…”