Waste gas exposure during desflurane and isoflurane anaesthesia

Background: Currently, there are no data available concerning the occupational exposure to desflurane during general anaesthesia. This prospective, randomized study reports on occupational exposure to desflurane, compared to isoflurane, in a modern operation theatre (OT). Methods: The study was performed in an OT equipped with a modern air-conditioning System and with a low-leakage anaesthesia machine connected to a central scavenging system. Trace concentrations of the anaesthetics were measured con tinuously by means of a photoacoustic infrared spectrometer during general anaesthesia in 30 patients undergoing eye surgery. Values were obtained within the breathing zone of the anaesthetist, the surgeon, the auxiliary nurse and at the mouth of the patient. Results: Desflurane and isoflurane were administered with median (range) endtidal concentrations of 4.7 (3.8-10.3) vol% and 0.9 (0.6-1.4) vol%, respectively. The personnel-related median values of the average trace concentrations of desflurane and isoflurane were 0.5 (0.01-7.5) ppm and 0.2 (0.01-1.6) ppm, respectively. Conclusions: Occupational exposure to desflurane is low in the environment of a modern OT, even though it has to be administered in approximately 5-fold higher concentrations compared to isoflurane.