[Exposure of operating room personnel to anesthetic gases during ENT interventions].

During ENT surgical procedures under general anesthesia contamination of the operating room air through waste anesthetic gases seems unavoidable. A resulting chronic low-level exposure to anesthetic gases in subanesthetic concentrations (m1/m3 = ppm) may cause various negative health effects. The aim of this study was to quantify possible side effects on operating room personnel. By using a highly sensitive, direct reading instrument for determining contamination leakage from a patient's mouth and resulting concentrations in the breathing zone of the surgeon and anesthetist, levels of isoflurane and nitrous oxide were measured at 2-min intervals during 20 ENT surgical procedures performed under usual workplace conditions. Despite high concentrations of anesthetic at the mouth of each patient, personnel-related mean values remained under recommended threshold values (TLV) of 10 ppm isoflurane. A TLV of 100 ppm nitrous oxide was exceeded in 20% of the operations. Furthermore, a safe TLV for pregnant staff was 25 ppm nitrous oxide. This value was exceeded during nearly all operations (93%) for the group "surgeon". High leakages at the patient's mouth led to an undesirably high contamination of operating room personnel by nitrous oxide. Although threshold values were mostly not exceeded in available working conditions (i.e., adequate air conditioning and intubation cuff pressure control), present health and safety regulations concerning pregnant women showed that the values of nitrous oxide were still too high to allow such women to work safely in operating rooms during surgery. However, exposure to isoflurane was too slight to classify.