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Protecting Your Staff from Waste Anesthetic Gas Exposure
Dwight Underhill
Publish Date: October 10, 2007   |  Tags:   Staff Safety

Dwight W. Underhill, PhD Operating room and PACU staff exposure to waste anesthetic gases is one of the least-understood OR hazards and one of the most difficult to prevent. The harm associated with these exposures may take years to develop, and when eventually seen, the underlying causes may go unrecognized. In addition, the concentrations of anesthetic waste gases that are of concern are so low as to seem almost immeasurable (see "How to Document Exposure").

We know exposure to waste anesthetic gases can cause many adverse effects. Short-term concentrated exposure can cause nausea and dizziness, as well as impaired judgment and coordination. Long-term effects may include sterility or miscarriages, as well as liver and kidney disease. The most common causes for exposure, according to OSHA, are poor or leaking connections from the gas lines and inadequate maintenance of anesthesia machines.

Reducing the risk
Even if your staff aren't being exposed to waste anesthetic gases, you should minimize the chance they will be. But maintaining a healthy atmosphere in a surgical facility is difficult, because anesthetic agents are intended to have a strong biological effect. Administrators and anesthesia providers must assume the responsibility of protecting staff as well as patients. OSHA offers the following recommendations to help you minimize OR and PACU staff exposure:

  • Regulate your OR air-flow system. There should be a minimum total of 15 air changes per hour, with a minimum of three changes of fresh air per hour. Don't recirculate OR air containing waste anesthetic gases to other ORs or areas of the facility.
  • Regularly inspect and maintain the anesthesia machine. Schedule this at least every four months. Gas leakage should be less than 100 ml/min under normal operation. Pay special attention to the scavenging system's performance in collecting and removing waste gas.
  • Pre-flight the anesthesia machine daily. Before the day's first case, your anesthesia personnel should check all connectors and tubes on the machine, as well as the alarm system and breathing circuits.
  • Safe housekeeping. Although staff are under pressure to keep cases moving, they should immediately clean up spilled liquid anesthesia gases to minimize exposure.

An invisible danger
Budgets are tight, and patient care is a more pressing concern than is controlling staff anesthetic gas exposure. Even so, you have a responsibility to your staff, not to mention staying in regulatory compliance and meeting accreditation standards.

The best source for details of sampling procedures is OSHA's Web site (www.osha-slc.gov/dts/sltc/methods/toc.html). You may also want to seek help from an industrial hygienist or a consulting company. A consultant may seem like a luxury if you're on a tight budget, but the most important thing you can do is provide a healthy environment for your staff.

Costs aside, you must implement effective safety protocols for protecting your staff from this invisible and dangerous byproduct of performing surgery.

How to Document Exposure

How do you document that the exposure to anesthetic waste gases is within permissible limits? Here are your main options:

  • Infrared monitors. Today's devices are portable and give real-time data. By changing the operational wavelength, an infrared monitor can measure independently both nitrous oxide and the halogenated anesthetic agents. On the downside, the instrument is expensive, must be used by a trained operator (usually an industrial hygienist) and obtaining data taken over an eight-hour workday, which is what OSHA prefers, can disrupt the OR schedule.

  • Pump samplers. These small pumps draw air through a sampling tube filled with adsorbent and pinned to the lapel of an employee. While it's possible to do it in-house, a trained industrial hygienist should take the measurements. There are also lab costs that you don't have with the infrared monitors. Accurate results with the samplers require a subsequent laboratory analysis of the adsorbent to determine the precise uptake.

  • Diffusive samplers. Commercial diffusive samplers resemble film badges in size and shape, are inexpensive and easily placed in the breathing zone of the employee and, unlike the other samplers, don't require power. Although some diffusive samplers can give real-time monitoring information, usually via a color change, this is not yet possible for anesthetic gases, and a later laboratory analysis of the uptake on the badge is required to establish the desired time-weighted average exposure.

- Dwight W. Underhill, PhD