Occupational exposure in hospitals to nitrous oxide and the new inhalation anaesthetics desflurane and sevoflurane

Background and objektive: There have been few studies of the occupational exposure of the new volatile anaesthetic agents desflurane and sevoflurane. Because a health risk through long-term exposure to these inhalants cannot as yet be definitely excluded, we undertook to measure the concentrations of these three anaesthetics in different parts of the Frankfurt University Medical Centre. Considering the results the relevance of exposure for surgical and anaesthesiogical personnel, possible consequences due to laws and possibilities of improvement were shown, Methods: The concentration of the three anaesthetics was measured during and after 345 procedures under general anaesthesia, using photoacoustic infra-red-spectrometry every 90 sec in the breathing zone of the same operating room personnel or in the recovery room and the intensive care unit. Results: Exposure of personnel in the air-conditioned operating rooms was very low, but in those rooms that were not or inadequately air conditioned was a times very high. The level of the concentrations was also significantly related to the anaesthesia system and the distance of the exposed person to the patient. The concentration of nitrous oxide was below the maximal working-place concentration (MWC) of 100 ppm, but it exceeded the threshold concentration of 0,1 MAC, as laid down in the,,Maternal Protection Law" in the surgical intensive care unit and the recovery room. There are no limiting concentrations for desflurance and sevoflurane yet but their concentrations were clearly below the MWC laid down for isoflurance and enflurane. Conclusion: In principle the use of inhalation anaesthetics tan be considered to be without occupational health risk under the present legally defined standards of air-conditioning and the requirements of a modern occupational protection law. Because of the increased concentrations in the recovery room and intensive care unit pregnant and breast-feeding women should not work in these areas.