NEUROTOXICITY IN OPERATING-ROOM PERSONNEL WORKING WITH GASEOUS AND NONGASEOUS ANESTHESIA

Occupational exposure to high concentrations of anesthetic gases (more than 500 ppm of nitrous oxide and more than 15 ppm of halothane and e nflurane) can cause neurobehavioral effects in operating room personne l. Factors such as stress and work organization play an additional rol e in reducing performance capacities. It is still unclear whether thes e conditions may become the predominant factor in behavioral impairmen t when exposure to anesthetic,eases is reduced; in addition, we wished to ascertain the extent of neurobehavioral and neuroendocrine effects at relatively low levels of exposure to such gases. Therefore the sam e group of 30 operating room personnel was examined with neurobehavior al tests during gaseous and nongaseous anesthesia. In this way, the ne uropsychological performance was examined under the same stress condit ions, but with different exposure levels to anesthetic gases. Serum co rtisol was measured as an additional ''biological stress indicator.'' Prolactin secretion was examined to study possible interference of ane sthetic gases with the dopaminergic system. The results were compared with those in a control group of 20 hospital workers from other depart ments, with similar characteristics in respect of age, sex, and educat ion. During work with gaseous anesthesia, average airborne concentrati ons (geometric mean) of nitrous oxide were 50.9 ppm (SD 20.5) on the f irst day of the working week and 54.2 ppm (SD 22.1) on the last day of the working week, whereas average urinary nitrous oxide (geometric me an) were 21.54 mu g/l on the first day of the working week and 25.67 m u g/l on the last day df the working week. The operating room workers showed slower reaction times at the end of the week with gaseous anest hesia, compared with workers using nongaseous anesthesia and the contr ol group. At the same time they also showed increased secretion of pro lactin, whereas cortisol remained unchanged. Therefore, it can be conc luded that lower levels of exposure to anesthetic gases (and not only high exposure levels) cause an impairment of neurobehavioral performan ce, with the action of stress being less relevant. The mechanism of an esthetics' neurotoxic action seems to be related to interference with the dopaminergic system.