The Relative Exposure of the Operating Room Staff to Sevoflurane During Intracerebral Surgery

BACKGROUND: Our primary aim in this study was to investigate whether escape of the volatile anesthetic sevoflurane from the surgical site during craniotomy for tumor resection increases the exposure of the neurosurgeon to the anesthetic when compared with the anesthesiologist. METHODS: Initially, the release of sevoflurane from the surgical site was measured during 35 tumorectomies starting from opening to closure of the dura. Volatile anesthetic absorbers were placed at three detection sites: 1) the surgeon’s breathing zone, 2) the anesthesiologist’s breathing zone, and 3) the farthest corner of the operation room. In the second sampling series that included 16 patients, the detector that had been in the corner of the operating room in the first series was now placed in the vicinity of the patient’s mouth (within 5 cm). Sevoflurane captured by the absorbers was quantified by an independent chemist using chromatography. RESULTS: Absorbers in the surgeon’s breathing zone (0.24 ± 0.04 ppm) captured a significantly lower amount of sevoflurane compared with absorbers in the anesthesiologist’s breathing zone (1.40 ± 0.37 ppm) and comparable with that in the farthest corner of the operation room (0.25 ± 0.07 ppm). There was no correlation between the amount of absorbed sevoflurane and the size of craniotomy window, even when adjusting for the variation in duration of surgery. In the second series of sampling, absorbers in the proximity of the patient’s mouth captured the highest amount of sevoflurane (1.54 ± 0.55 ppm), followed by the anesthesiologist’s (1.14 ± 0.43 ppm) and the surgeon’s (0.15 ± 0.05 ppm) breathing zones. CONCLUSIONS: The close proximity of the surgeon’s breathing zone to the craniotomy window does not appear to be a source of increased exposure to sevoflurane. The observed higher exposure of the anesthesiologist to sevoflurane in the operating room environment warrants further exploration.