[Exposure of recovery room personnel to inhalation anesthetics]

Both desflurane and sevoflurane have a favourable blood/gas distribution coefficient. There is concern, however, that environmental contamination is higher when these agents are employed since they must be used in relatively high concentrations. Our study seeks to determine the degree of exposure of recovery room staff to trace amounts of these two agents. Two hundred and seven surgical patients were included in the study. The recovery room studied had a volume of 243 cubic metres. The hourly fresh air supply for this room was 1,845 cubic metres, which results in 7.6 air exchanges per hour without air return. Measurements of trace concentrations of the inhalational agents were taken for 12 days. Concentrations of these anaesthetics were assessed in the recovery room with a real-time infrared spectrometer every 90 seconds. Mean exposure to nitrous oxide in the recovery room was 11.5 +/- 3.97 ppm and to isoflurane 1.4 +/- 0.31 ppm. All measured values were below the standard German threshold values. Trace concentrations of desflurane were 2.8 +/- 0.84 ppm and of sevoflurane 3.2 +/- 0.62 ppm. We conclude that the exposure to the inhalational anaesthetics in the climatised recovery room was low. The threshold values of 100 ppm for nitrous oxide and 10 ppm for isoflurane recommended by German law were not exceeded. When the new volatile anaesthetics are used, exposure of recovery room staff to trace concentrations of these agents is higher, but the concentrations do not exceed the levels allowed applicable German health regulations.