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

Background and objektive: There have been few studies of the occupational e xposure 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 o f these three anaesthetics in different parts of the Frankfurt University M edical Centre. Considering the results the relevance of exposure for surgic al and anaesthesiogical personnel, possible consequences due to laws and po ssibilities of improvement were shown, Methods: The concentration of the three anaesthetics was measured during an d 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 v ery low, but in those rooms that were not or inadequately air conditioned w as a times very high. The level of the concentrations was also significantl y related to the anaesthesia system and the distance of the exposed person to the patient. The concentration of nitrous oxide was below the maximal wo rking-place concentration (MWC) of 100 ppm, but it exceeded the threshold c oncentration of 0,1 MAC, as laid down in the,,Maternal Protection Law" in t he surgical intensive care unit and the recovery room. There are no limitin g concentrations for desflurance and sevoflurane yet but their concentratio ns were clearly below the MWC laid down for isoflurance and enflurane. Conclusion: In principle the use of inhalation anaesthetics tan be consider ed to be without occupational health risk under the present legally defined standards of air-conditioning and the requirements of a modern occupationa l protection law. Because of the increased concentrations in the recovery r oom and intensive care unit pregnant and breast-feeding women should not wo rk in these areas.