Anesthetic gas exposure. Protecting the OR environment

A trace gas study was conducted at The University of Michigan Hospitals to assess levels of anesthetic gas in the OR environment. Samples were collected at various sites associated with anesthesia equipment in 18 operating rooms and three treatment rooms where general anesthesia was used routinely. Waste anesthetic gas levels were found to vary widely and, depending upon anesthesiologists' work practices and equipment design, significant personnel exposures were documented. Although standard turbulent air flow, nonrecirculating systems are used in most ORs, areas of high gas concentration were identified. Such locations included the area between the gas machine and adjacent wall, and along the perimeter of the patient drapes. Gas concentrations were influenced by such variables as the distance from the anesthesia equipment to the exhaust grilles, and personnel movement. Anesthetizing techniques and work practices are the major contributors to waste anesthesia levels in the OR environment.