Healthcare workers in a variety of settings can be exposed to the anesthetic gases that are released or leak out during medical procedures. These gases and vapours are known as waste anesthetic gases (WAGs).
People who work in hospitals in areas such as operating, labour and delivery rooms, recovery rooms, and in remote anesthetic locations such as radiology or post anesthetic care unit, as well, those who work in dental offices and veterinary clinics and animal research facilities may be exposed to waste anesthetic gases.
Gases most commonly used include nitrous oxide, isoflurane, desflurane, and sevoflurane.
NIOSH (the National Institute for Occupational Safety and Health) reports the effects of high concentration exposures to WAGs include dizziness, feelings of light headiness, nausea, fatigue, headache, irritability, and depression. Other effects include liver and kidney disease. Exposed workers can experience difficulty with cognitive, perception, judgment, and motor skills placing themselves and others at risk.
Effects of exposure to low concentrations can also include miscarriage, birth defects (genetic damage), and cancer in exposed workers and their spouses (in cases of miscarriages and birth defects).
Health workers can be exposed in a variety of ways.
An effective waste anesthetic gas management program includes:
A well-designed WAG scavenging system to collect, remove, and properly dispose of the gases - Care should be exercised so that the gases are not discharged near the air intake of the building or surrounding buildings. The scavenging system should be kept in good repair to prevent leaks using a maintenance and inspection program as listed below.
Properly designed equipment - For example, a mask should consist of a shroud large enough to capture gases exhaled from the patient's mouth.
Proper maintenance and inspection programs should be written and carried out for the WAG scavenging system, anesthesia machines, and the ventilation system. The scavenging system, anesthesia machines, and respirators must be checked daily for leaks and properly monitored.
Use of anesthetic agents supplied in bottles with an integrated fused filling adaptor, or use of local ventilation/hoods when using standard bottles for filling and refilling of vapourizers. The risk of a leak while filling/refilling a vaporizer (e.g., removing the screw cap, installation of adaptors, etc) can increase the chance of exposure. Use of a local ventilation hood, ventilation cabinet, or a local scavenging device is preferred. Bottles with an integrated fused filling adaptor do not require this step.
Proper work practices are a vital aid in reducing exposure of health care personnel to WAGs.
Improper anesthetizing techniques may include:
One of the tools used to measure exposure to waste anesthetic gases is air monitoring. The information collected through air monitoring is critically important to the proper design and implementation of engineering controls and work practices.
Monitoring may be continuous or periodic but should adequately measure exposure in the work areas and surrounding areas.
Monitoring can aid in identifying the presence and location of leaked gases and the effectiveness of corrective measures.
As most halogenated anesthetic gases cannot be detected by smell (unless they are in high concentration) proper monitoring becomes all the more critical. Nitrous oxide is an odourless and colourless gas and can only be detected by WAG monitor.
Employers should develop and implement a written hazard communication program regarding WAGs that includes description of the physical and health hazards of anesthetic agents in use, the compiling and availability of up to date material safety data sheets on all anesthetic gases used; proper labelling of canisters, tanks, and containers; and a comprehensive employee training and information program.
The training program should list steps workers can take to protect themselves from the hazards of WAGs. The program should include information on steps taken by the employer such as engineering controls, clearly outline emergency procedures to contain spills, describe safe work practices and the use of any personal protective equipment, and detail the use of continuous monitoring devices.
The training program should clearly outline all methods and observable indicators that can detect the presence and release of anesthetic gases.
Spills should be treated as emergencies. Spills of anesthetic agents must only be cleaned up and controlled by properly trained and equipped personnel.
Document last updated on June 13, 2012