[Environmental and biological control in a population exposed to isoflurane in the operating room].

OBJECTIVE

To measure the level of occupational exposure to isoflurane in the operating room, and to determine the relation between isoflurane concentration in atmospheric and exhaled air.

PATIENTS AND METHODS

One hundred seventy-eight samples were obtained from 60 male and female subjects who work in the operating room of our hospital. To monitor workplace exposure we used passive diffusion samplers. Biological monitoring (isoflurane in exhaled air) was accomplished with standard adsorption tubes to collect exhaled air samples. Gases were thermically separated and analyzed by gas chromatography.

RESULTS

Atmospheric isoflurane concentrations ranged between 1.14 and 157.23 mg/m3 (geometric mean 16.23 mg/m3). Exhaled isoflurane concentrations ranged from 0.15 to 26.09 mg/m3 (geometric mean 2.85 mg/m3). Atmospheric and exhaled isoflurane concentrations were strongly related (r = 0.82; p < 0.0001). Linearity was determined by the following equation: log of exhaled isoflurane concentration = -0.69 + 0.95 log of atmospheric isoflurane concentration.

CONCLUSIONS

The concentrations of isoflurane in atmospheric and exhaled air found in our study exceed the maximum levels for halogenated gases recommended by the National Institute for Occupational Safety and Health, although they do not exceed the levels stipulated by Swiss authorities. In order to adequately assess operating room antipollution measures, atmospheric and biologic monitoring of isoflurane and other inhaled anesthetic gas concentrations is necessary.