Copyright © 2018, the American Society of Anesthesiologists, Inc. Wolters Kluwer Health, Inc. Unauthorized reproduction of this article is prohibited. <zdoi;10.1097/ALN.0000000000002181> Anesthesiology, V 129 • No 1 67 July 2018 P OSTOPERATIVE pulmonary complications are com- mon and afect morbidity and mortality in patients undergoing major surgery. 1 Intraoperative ventilation strate- gies for lung protection include low tidal volume, positive end-expiratory pressure (PEEP), and recruitment maneu- vers. Tese strategies appear to improve clinical outcomes in patients undergoing major abdominal surgery. 2 However, the strategies do not consider supplemental oxygen, which is an essential component of ventilator management. Supplemental oxygen administration during mechani- cal ventilation is important for preventing or correcting hypoxemia, both in the intensive care unit and in the opera- tion theater. Several observational studies of intensive care unit patients receiving mechanical ventilation found that conventional oxygen therapy was liberally administered, and this could potentially induce hyperoxemia, 3–6 which is a potentially injurious condition. High oxygen levels can enhance reactive oxygen species formation and oxida- tive stress, induce peripheral vasoconstriction, and decrease cardiac output. 7,8 Moreover, adverse clinical outcomes What We Already Know about This Topic • Despite the potentially harmful effects of oxygen overexposure, supplemental oxygen therapy is commonly prescribed in several clinical conditions. However, little is known about current oxygen administration practices during general anesthesia. What This Article Tells Us That Is New • In this multicenter, cross-sectional study of 1,498 patients at 43 hospitals, potentially preventable hyperoxemia and substantial oxygen exposure were common during general anesthesia, especially in patients receiving one-lung ventilation. Copyright © 2018, the American Society of Anesthesiologists, Inc. Wolters Kluwer Health, Inc. All Rights Reserved. Anesthesiology 2018; 129:67-76 ABSTRACT Background: Intraoperative oxygen management is poorly understood. It was hypothesized that potentially preventable hyperoxemia and substantial oxygen exposure would be common during general anesthesia. Methods: A multicenter, cross-sectional study was conducted to describe current ventilator management, particularly oxygen management, during general anesthesia in Japan. All adult patients (16 yr old or older) who received general anesthesia over 5 consecutive days in 2015 at 43 participating hospitals were identifed. Ventilator settings and vital signs were collected 1 h after the induction of general anesthesia. We determined the prevalence of potentially preventable hyperoxemia (oxygen saturation measured by pulse oximetry of more than 98%, despite fractional inspired oxygen tension of more than 0.21) and the risk factors for potentially substantial oxygen exposure (fractional inspired oxygen tension of more than 0.5, despite oxy- gen saturation measured by pulse oximetry of more than 92%). Results: A total of 1,786 patients were found eligible, and 1,498 completed the study. Fractional inspired oxygen tension was between 0.31 and 0.6 in 1,385 patients (92%), whereas it was less than or equal to 0.3 in very few patients (1%). Most patients (83%) were exposed to potentially preventable hyperoxemia, and 32% had potentially substantial oxygen exposure. In multivariable analysis, old age, emergency surgery, and one-lung ventilation were independently associated with increased potentially substantial oxygen exposure, whereas use of volume control ventilation and high positive end-expiratory pressure levels were associated with decreased potentially substantial oxygen exposure. One-lung ventilation was particularly a strong risk factor for potentially substantial oxygen exposure (adjusted odds ratio, 13.35; 95% CI, 7.24 to 24.60). Conclusions: Potentially preventable hyperoxemia and substantial oxygen exposure are common during general anesthe- sia, especially during one-lung ventilation. Future research should explore the safety and feasibility of a more conservative approach for intraoperative oxygen therapy. (ANESTHESIOLOGY 2018; 129:67-76) This article is featured in “This Month in Anesthesiology,” page 1A. Supplemental Digital Content is available for this article. Direct URL citations appear in the printed text and are available in both the HTML and PDF versions of this article. Links to the digital files are provided in the HTML text of this article on the Journal’s Web site (www.anesthesiology.org). Submitted for publication June 27, 2017. Accepted for publication February 15, 2018. From the Department of Anesthesiology and Resuscitology, Okayama University Hospital, Okayama, Japan (S.S., Y.M., Y.H., S.O., H.M.); and Department of Medical Statistics, Osaka City University Graduate School of Medicine, Osaka, Japan (T.I., A.S.). *Members of the Okayama Research Investigation Organizing Network (ORION) investigators are listed in the appendix. Current Ventilator and Oxygen Management during General Anesthesia A Multicenter, Cross-sectional Observational Study Satoshi Suzuki, M.D., Ph.D., Yuko Mihara, R.N., Yukiko Hikasa, M.D., Shuji Okahara, M.D., Takuma Ishihara, M.S., Ayumi Shintani, Ph.D., M.P.H., Hiroshi Morimatsu, M.D., Ph.D., on behalf of the Okayama Research Investigation Organizing Network (ORION) investigators* Downloaded from http://pubs.asahq.org/anesthesiology/article-pdf/129/1/67/385862/20180700_0-00017.pdf by guest on 10 June 2022