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

Abstract

Objective During the induction of gaseous anaesthesia, waste anaesthetic gases (WAGs) can be released into workplace air. Occupational exposure to high levels of halogenated WAGs may lead to adverse health effects; hence, it is important to measure WAGs concentration levels to perform risk assessment and for health protection purposes. Methods A systematic review of the scientific literature was conducted on two different scientific databases (Scopus and PubMed). A total of 101 studies, focused on sevoflurane, desflurane and isoflurane exposures in hospitals, were included in this review. Key information was extracted to provide (1) a description of the study designs (e.g., monitoring methods, investigated occupational settings, anaesthetic gases in use); (2) an evaluation of time trends in the measured concentrations of considered WAGs; (3) a critical evaluation of the sampling strategies, monitoring methods and instruments used. Results Environmental monitoring was prevalent (68%) and mainly used for occupational exposure assessment during adult anaesthesia (84% of cases). Real-time techniques such as photoacoustic spectroscopy and infrared spectrophotometry were used in 58% of the studies, while off-line approaches such as active or passive sampling followed by GC-MS analysis were used less frequently (39%). Conclusions The combination of different instrumental techniques allowing the collection of data with different time resolutions was quite scarce (3%) despite the fact that this would give the opportunity to obtain reliable data for testing the compliance with 8 h occupational exposure limit values and at the same time to evaluate short-term exposures.

Keywords: healthcare workers; hospital staff; inhaled anaesthetics; operating rooms; volatile compounds; waste anaesthetic gases.

Figure 1

Flowchart of the literature research and review process [39].

Figure 2

Graphical description (relative frequencies, %) of main characteristics of WAGs exposure monitoring in the investigated literature. (a) WAGs; (b) hospital environments; (c) anaesthesia subjects; (d) scavenging system; (e) monitoring type; (f) sampling type; (g)time-integrated techniques; (h) real-time techniques.

Figure 3

Median (circle, triangle and square), maximum and minimum (error bars) values of sevoflurane, isoflurane and desflurane concentrations in the 1990s, 2000s, 2010s, and number of studies considered per anaesthetic gas.

Figure 4

Median (circle, triangle and square), maximum and minimum (error bars) values of all three gases concentrations (sevoflurane, isoflurane and desflurane) in the operating room, post-anesthesia and intensive care units, respectively. Divided in decades (1990s, 2000s, 2010s), number of studies considered per different hospital areas are shown.

Figure 5

Median (circle and triangle), maximum and minimum (error bars) values of all three gases concentrations (sevoflurane, isoflurane and desflurane) with and without scavenging system, respectively. Divided in decades (1990s, 2000s, 2010s), number of studies considered per mitigation techniques of WAGs are shown.

Figure 6

Block Diagram of monitoring approaches for anaesthetic gases. PAS = photoacoustic spectroscopy; IR = infrared spectrophotometry; PTR-MS = proton-transfer-reaction mass spectrometry; IMS = ion mobility spectrometer.