Occupational chronic sevoflurane exposure in the everyday reality of the anesthesia workplace
BACKGROUND: Although sevoflurane is one of the most commonly used volatile anesthetics in clinical practice, anesthesiologists are hardly aware of their individual occupational chronic sevoflurane exposure. Therefore, we studied sevoflurane concentrations in the anesthesiologists' breathing zones, depending on the kind of induction for general anesthesia, the used airway device, and the type of airflow system in the operating room. Furthermore, sevoflurane baselines and typical peaks during general anesthesia were determined. METHODS: Measurements were performed with the LumaSense Photoacoustic Gas Monitor. As we detected the gas monitor's cross-sensitivity reactions between sevoflurane and disinfectants, regression lines for customarily used disinfectants during surgery (Cutasept®, Octeniderm®) and their alcoholic components were initially analyzed. Hospital sevoflurane concentrations were thereafter measured during elective surgery in 119 patients. The amount of inhaled sevoflurane by anesthesiologists was estimated according to mVA = cVA × × t × ρVA aer. RESULTS: Induction of general anesthesia stopped after tracheal intubation with the patient's expiratory sevoflurane concentration of 1.5%. Thereby, inhalational inductions (INH) caused higher sevoflurane concentrations than IV inductions (mean [SD]: [ppm] INH 2.43 ±1.91 versus IV 0.62 ± 0.33, P &lt; 0.001; mVA [mg] INH 1.95 ± 1.54 versus IV 0.30 ± 0.22, P &lt; 0.001). The use of laryngeal mask airway (LMA™) led to generally higher sevoflurane concentrations in the anesthesiologists' breathing zones than tracheal tubes ([ppm] tube 0.37 ± 0.16 versus LMA™ 0.79 ± 0.53, P = 0.009; [ppm] tube 1.91 ± 0.91 versus LMA™ 2.91 ± 1.81, P = 0.057; mVA [mg] tube 1.47 ± 0.64 versus LMA™ 2.73 ± 1.81, P = 0.019). Sevoflurane concentrations were trended higher during surgery in operating rooms with turbulent flow (TF) air-conditioning systems compared with laminar flow (LF) air-conditioning systems ([ppm] TF 0.29 ± 0.12 versus LF 0.13 ± 0.06, P = 0.012; mVA [mg/h] TF 1.16 ± 0.50 versus LF 0.51 ± 0.25, P = 0.007). CONCLUSIONS: Anesthesiologists are chronically exposed to trace concentrations of sevoflurane during work. Inhalational inductions, LMA™, and TF air-conditioning systems in particular are associated with higher sevoflurane exposure. However, the amount of inhaled sevoflurane per day was lower than expected, perhaps because concentrations in previous measurements could be overestimated (10%-15%) because of the cross-sensitivity reaction. © 2015 International Anesthesia Research Society.