Does standing or sitting position of the anesthesiologist in the operating theatre influence sevoflurane exposure during craniotomies?

Refocusing on work-based hazards for the anaesthesiologist in a post-pandemic era

The coronavirus pandemic has raised public awareness of one of the many hazards that healthcare workers face daily: exposure to harmful pathogens. The anaesthesia workplace encompasses the operating room, interventional radiology suite, and other sites that contain many other potential occupational and environmental hazards. This review article highlights the work-based hazards that anaesthesiologists and other clinicians may encounter in the anaesthesia workplace: ergonomic design, physical, chemical, fire, biological, or psychological hazards. As the anaesthesia work environment enters a post-COVID-19 pandemic phase, anaesthesiologists will do well to review and consider these hazards. The current review includes proposed solutions to some hazards and identifies opportunities for future research.

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

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.

Probabilistic health risk assessment of occupational exposure to isoflurane and sevoflurane in the operating room

Risk assessment is an important tool in predicting the possible risk to health. It heightens awareness by estimating the probability of adverse health effects in humans who are exposed to chemicals in the course of their work. Therefore, the present work aims to determine the occupational exposure of operating room staff to the volatile anesthetic gases, isoflurane and sevoflurane, and estimates non-cancer risk using the United States Environmental Protection Agency method. Air samples from the breathing zone of staff members were collected using the Occupational Safety and Health Administration Method 103 and analyzed using gas chromatography-mass spectroscopy. The results indicate that the measured concentrations of isoflurane and sevoflurane are below the National Institute of Occupational Safety and Health standard (2 ppm) for technicians and nurses, but not for anesthesiologists and surgeons. Moreover, the estimated non-cancer risk due to isoflurane is above the acceptable value for anesthesiologists (but acceptable for other occupational categories). A sensitivity analysis indicates that exposure time has the most effect on calculated risk (53.4%). Occupational exposure to anesthetic gases may endanger the health of operating room personnel. Therefore, control measures, such as daily testing of anesthetic devices, ensuring the effectiveness of ventilation systems, advanced scavenging methods, and regular training of staff are highly recommended.

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

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™), 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 short-term 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.

Occupational exposure to sevoflurane following topical application to painful wounds

BACKGROUND

Occupational exposure to halogenated anesthetics employed for general anesthesia has been extensively studied. Conversely, a new modality of treatment of painful wounds with topical sevoflurane lacks exposure studies.

OBJECTIVES

To evaluate the magnitude of acute occupational exposure to sevoflurane following topical application to painful wounds.

METHODS

Four patients with chronic painful wounds were treated with topical sevoflurane (20, 20, 20 and 10 mL) following an approved therapeutic protocol in our Pain Management Unit. Eight passive dosimeters were placed at different locations of a treatment room with a volume of 163 m3 and 3.3 air changes per hour: 3 for near peak (for 20-50 min) and 1 overall exposure (for 3.4 h) at the nurse's breathing zone, and 4 for area exposure (for 3-3.4 h). Worst-case scenario theoretical concentrations of sevoflurane were also calculated.

RESULTS

The highest levels were obtained for two dosimeters worn by the nurse at the breathing zone (8.28 and 9.12 ppm-TWA [parts per million-Time-Weighted Average]), while the lowest level was obtained from the dosimeter placed on the most distant wall from patients (0.73 ppm-TWA). Theoretical concentrations were calculated from standard volatilization principles and were in agreement with the concentrations measured. Discussion-Conclusions: All air concentrations measured were lower than exposure limits set by occupational safety agencies from Finland, Sweden and Norway, which range from 10 ppm for a TWA of 8 hours to 20 ppm for short-term exposures (15 min). Application of topical sevoflurane on wounds seems to be environmentally safe for health-care professionals as it produces exposure levels lower than the established limits for anesthetic procedures.

Waste anesthetic gas exposure and strategies for solution

As inhaled anesthetics are widely used, medical staff have inevitably suffered from exposure to anesthetic waste gases (WAGs). Whether chronic exposure to WAGs has an impact on the health of medical staff has long been a common concern, but conclusions are not consistent. Many measures and equipment have been proposed to reduce the concentration of WAGs as far as possible. This review aims to dissect the current exposure to WAGs and its influence on medical staff in the workplace and the environment, and summarize strategies to reduce WAGs.