EXPOSURE OF POSTOPERATIVE NURSES TO EXHALED ANESTHETIC-GASES

The National institute of Occupational Safety and Health (NIOSH) has e stablished recommended exposure limits of 25 parts per million (ppm) a s a time-weighted average for nitrous oxide and a ceiling of 2 ppm for volatile anesthetics. We quantified exposure of postanesthetic nurses to exhaled anesthetic gases. This study was conducted in the postanes thesia care unit (PACU) of a medium-sized hospital. PACU air exchanges averaged 8 vol/h; however, much of this air was recirculated. We eval uated 50 adults anesthetized with either isoflurane (n = 19) or desflu rane (n = 31). Roughly half the patients were tracheally extubated in the operating room, whereas the others were extubated just after admis sion to the PACU. Exhaled anesthetic gases were sampled through a 20-m hose attached to the participating nurses' shoulders (breathing zone) . We also evaluated nursing exposure to exhaled anesthetic gases durin g recovery of 15 patients who had been anesthetized with nitrous oxide . Exposure was quantified with lapel dosimeters. Anesthetic and recove ry durations were each approximately 1 h, with most patients being tra cheally extubated in the PACU. Breathing-zone anesthetic concentration s in the patients given isoflurane exceeded NIOSH recommendations in 3 7% of the patients, representing 12% of recovery time. Breathing-zone anesthetic concentrations in the patients given desflurane, however, e xceeded NIOSH limits in 87% of the patients, representing 49% of recov ery time. Altogether, noncompliant episodes were detected in 68% of th ese patients, representing 35% of the entire recovery duration. Breath ing-zone anesthetic concentrations in the patients given nitrous oxide exceeded NIOSH limits in 53% of the patients. Our data suggest that p ostoperative nurses' exposure to exhaled anesthetic gases exceeds NIOS H limits under some circumstances. Implications: Some epidemiological evidence suggests that exposure to waste anesthetic gases may be assoc iated with reproductive toxicity. Accordingly, the National institute of Occupational Safety and Health has established recommended exposure limits for nitrous oxide and volatile anesthetics. Our data suggest t hat exposure of healthcare personnel may exceed recommended levels in poorly ventilated postanesthesia care units.