Occupational exposure to nitrous oxide and desflurane during ear-nose-throat-surgery

Purpose: To determine occupational exposure of the anesthesiologist and sur geon to nitrous oxide and desflurane during general anesthesia for ear-nose -throat (ENT) surgery in children and adults. Methods: An observational clinical trial was performed in ten children (C) and ten adults (A), Tracheas were intubated, in adults, with cuffed tubes a nd in children with uncuffed tubes. The operating room was equipped with mo dern air conditioning and waste anesthetic gas scavengers. Gas samples were obtained during the operative procedure every 90 sec from the breathing zo ne of subjects. Time-weighted averages (TWA) over the time of exposure were calculated for nitrous oxide and desflurane. Results: Nitrous oxide TWAs for anesthesiologists were 0.41 +/- 0.23 ppm (A ) and 1.20 +/- 0.32 ppm (C, P < 0.000 1), and 2.24 +/- 1.93 ppm (A) and 5.3 0 +/- 0.60 ppm (C, P = 0.000 1) for the surgeon who worked close to the pat ient's airway and thus had higher exposure (P < 0.05 [A], P < 0.000 1 [C]). With regard to desflurane, the anesthesiologists' TWAs were 0.02 +/- 0.03 ppm for both adults and children. The surgeon was exposed to 0.21 +/- 0.24 ppm desflurane (A) and 0.30 +/- 0.14 ppm (C, P: n.s.). Although the surgeon 's exposure was greater (P < 0.05 [A], P ( 0.000 1 [C]), the threshold limi ts of 25 ppm for nitrous oxide and 2 ppm for desflurane recommended by the National Institute of Occupational Safety and Health were not exceeded. Conclusions: tinder modem air conditioning, occupational exposure to inhala tional anesthetics is low, and inhalational anesthesia is safe from the sta ndpoint of modern workplace laws and health-care regulations.