Postoperative environmental anesthetic vapour concentrations following removal of the airway device in the operating room versus the postanesthesia care unit.
OBJECTIVE
This study was designed to compare waste anesthetic gas (WAG) concentrations within patients' breathing zones after removal of the patient's airway device in the postanesthesia care unit (PACU) vs in the operating room (OR).


METHODS
Following Research Ethics Board approval and patient consent, we recruited patients undergoing surgery who received volatile anesthesia via an endotracheal tube or supraglottic airway. Patients had their airway device removed in the OR or in the PACU depending on the attending anesthesiologist's preference. Upon the patient's arrival in the PACU, concentrations of exhaled sevoflurane and desflurane were measured at their breathing zone (i.e., 15 cm from the patient's mouth and nose) using a single-beam infrared spectrophotometer.


RESULTS
Seventy patients were recruited during the five-month study period. The median [interquartile range] WAG levels in the patients' breathing zones were higher when their airway devices were removed in the PACU vs in the OR. The WAG levels for sevoflurane were 0.7 [0.4-1.1] parts per million (ppm) vs 0.5 [0.4-0.7] ppm, respectively; median difference, 0.3; 95% confidence interval (CI), 0.1 to 0.6; P = 0.04. The WAG levels for desflurane were 2.4 [1.2-3.4] ppm vs 4.1 [2.5-5.2] ppm, respectively; median difference, 1.5; 95% CI, 0.3 to 2.7; P = 0.04.


CONCLUSIONS
After a volatile-based anesthetic, our results suggest that removal of the airway device in the PACU vs in the OR increases the amount of waste anesthetic gas in a patient's breathing zone and thus potentially in the PACU nurse's working zone.
Department of Anaesthesia, Pamela Youde Nethersole Eastern Hospital, Hong Kong, SAR, China.
Sara K
SK
Cheung
Department of Anesthesiology & Pain Medicine, University of Alberta, 2-150 Clinical Sciences Building, Edmonton, AB, T6G 2G3, Canada. ozelsel@ualberta.ca.
Timur
T
Özelsel
Department of Anesthesiology & Pain Medicine, University of Alberta, 2-150 Clinical Sciences Building, Edmonton, AB, T6G 2G3, Canada.
Saifee
S
Rashiq
Department of Anesthesiology & Pain Medicine, University of Alberta, 2-150 Clinical Sciences Building, Edmonton, AB, T6G 2G3, Canada.
Ban C
BC
Tsui
D000328:Adult; D000368:Aged; D016902:Air Pollution, Indoor / Q000032:analysis*; D018685:Anesthetics, Inhalation / Q000032:analysis*; D000077335:Desflurane; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D007530:Isoflurane / Q000031:analogs & derivatives / Q000032:analysis; D008297:Male; D008738:Methyl Ethers / Q000032:analysis; D008875:Middle Aged; D009726:Nurses; D016273:Occupational Exposure; D009873:Operating Rooms; D011184:Postoperative Period; D011997:Recovery Room; D000077149:Sevoflurane; D013055:Spectrophotometry, Infrared
D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane; D000077335:Desflurane; D007530:Isoflurane