OCCUPATIONAL EXPOSURE TO DESFLURANE AND ISOFLURANE DURING CARDIOPULMONARY BY PASS - IS THE GAS OUTLET OF THE MEMBRANE-OXYGENATOR AN OPERATING-THEATER POLLUTION HAZARD

We have compared occupational exposure to isoflurane and desflurane du ring cardiopulmonary bypass, with and without a scavenging system at t he membrane oxygenator outlet. Trace concentrations of volatile anaest hetics were measured by a direct reading instrument in 40 elective hea rt surgery procedures. Measurements were obtained in the breathing zon es of the anaesthetist and perfusionist. When a scavenging system was used, median desflurane values were less than 0.3 ppm and isoflurane v alues less than 0.2 ppm. Without a scavenging system values were, in g eneral, three- (isoflurane) to five- (desflurane) fold higher. We conc lude that the use of a scavenging system at the membrane oxygenator ou tlet can reduce occupational exposure to volatile anaesthetics. We the refore recommend routine use of scavenging devices during cardiopulmon ary bypass.