{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T06:15:46Z","timestamp":1778134546355,"version":"3.51.4"},"reference-count":28,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T00:00:00Z","timestamp":1778112000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"\n Background<\/jats:title>\n \n The updated global criteria for diagnosing acute respiratory distress syndrome (ARDS) include SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n as a substitute for PaO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n to enhance practicality in settings with limited resources and reduce reliance on arterial blood gas testing. However, the applicability of these SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n thresholds in high-altitude regions remains unvalidated. This study investigated the relationship between the SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n and PaO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n in patients with ARDS in the Xining region of Qinghai and validated whether the critical values for hypoxemia severity classification based on SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n are applicable in this population. A retrospective analysis was conducted on the clinical data of 276 patients with ARDS admitted to the intensive care unit (ICU) of Qinghai Provincial People\u2019s Hospital from October 2020 to October 2024. All patients who met the inclusion criteria were classified into mild, moderate, and severe ARDS as defined by the Berlin Definition. Spearman\u2019s correlation analysis was used to assess the correlation between SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n (corrected) and PaO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n (corrected). Curve estimation was used to derive the linear and nonlinear relationships between SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n and PaO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n , as well as between SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n (corrected) and PaO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n (corrected). Receiver operating characteristic curve analysis was used to validate whether the cutoff values proposed by the new global definition for SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n -based hypoxemia severity stratification apply to Xining.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n A significant nonlinear relationship was observed between the SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n and PaO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n ratios. The optimal fitting model was a power function model: SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n (corrected)\u202f=\u202f5.661\u202f\u00d7\u202f[PaO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n (corrected)]\n 0<\/jats:sup>\n \u00b7\n 71<\/jats:sup>\n . The area under the curve (AUC) of the SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n (corrected) for predicting mild ARDS was 0.912, with an optimal diagnostic threshold cutoff value of 360.4. For moderate ARDS, the AUC was 0.487, with a cutoff value of 238.8. For severe ARDS, the AUC was 0.956, with an optimal cutoff value of 168.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusion<\/jats:title>\n \n This study revealed a nonlinear relationship between the SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n and PaO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n ratios in patients with ARDS in Xining, Qinghai Province, a characteristic that may better align with the pathophysiological features of high-altitude regions. The globally redefined hypoxemia grouping thresholds based on SpO\n 2<\/jats:sub>\n \/FiO\n 2<\/jats:sub>\n may not apply to this area, suggesting that regional diagnostic criteria should be established according to altitude variations.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fmed.2026.1774390","type":"journal-article","created":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T05:42:03Z","timestamp":1778132523000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Relationship between SpO2\/FiO2 and PaO2\/FiO2 in patients with acute respiratory distress syndrome: a single-center, retrospective cohort study from Xining, China"],"prefix":"10.3389","volume":"13","author":[{"given":"Jian","family":"Sun","sequence":"first","affiliation":[{"name":"School of Clinical Medicine, Qinghai University","place":["Xining, Qinghai, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jing","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Clinical Medicine, Qinghai University","place":["Xining, Qinghai, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Litao","family":"Guo","sequence":"additional","affiliation":[{"name":"The First Affiliated Hospital of Xi\u2019an Jiaotong University","place":["Xi'an, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaoqin","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Critical Care Medicine, Qinghai Provincial People\u2019s Hospital Xining","place":["Xining, Qinghai, China"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2026,5,7]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"37","DOI":"10.1164\/rccm.202303-0558WS","article-title":"A new global definition of acute respiratory distress syndrome","volume":"209","author":"Matthay","year":"2024","journal-title":"Am J Respir Crit Care Med"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"1930","DOI":"10.3390\/diagnostics15151930","article-title":"Old and new definitions of acute respiratory distress syndrome (ARDS): an overview of practical considerations and clinical implications","volume":"15","author":"Biuzzi","year":"2025","journal-title":"Diagnostics"},{"key":"ref3","first-page":"434","article-title":"Research Progress on diagnosis of acute respiratory distress syndrome at high altitude","volume":"18","author":"Guo","year":"2023","journal-title":"China Med"},{"key":"ref4","first-page":"000281","volume-title":"Comparison of SpO","author":"Duan","year":"2019"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"1086","DOI":"10.1016\/S2213-2600(22)00058-3","article-title":"Pulse oximetry for the diagnosis and management of acute respiratory distress syndrome","volume":"10","author":"Wick","year":"2022","journal-title":"Lancet Respir Med"},{"key":"ref6","first-page":"29","article-title":"Understanding acute respiratory distress syndrome in high-altitude environments: a comprehensive review of diagnosis and treatment","author":"Guo","year":"2023","journal-title":"Med Sci Monit"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"225","DOI":"10.1016\/0034-5687(94)00094-G","article-title":"Oxygen enrichment of room air to relieve the hypoxia of high altitude","volume":"99","author":"West","year":"1995","journal-title":"Respir Physiol"},{"key":"ref8","doi-asserted-by":"publisher","DOI":"10.1001\/jama.2012.5669","article-title":"Acute Respiratory Distress Syndrome: The Berlin Definition","volume":"307","author":"Ranieri","year":"2012","journal-title":"JAMA"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"648835","DOI":"10.3389\/fmed.2022.648835","article-title":"Definition of acute respiratory distress syndrome on the plateau of Xining, Qinghai: a verification of the Berlin definition altitude-PaO2\/FiO2-corrected criteria","volume":"9","author":"Liu","year":"2022","journal-title":"Front Med"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"218","DOI":"10.1016\/j.arbr.2019.06.020","article-title":"Hospital mortality and effect of adjusting PaO2\/FiO2 according to altitude above the sea level in acclimatized patients undergoing invasive mechanical ventilation","volume":"56","author":"Jibaja","year":"2020","journal-title":"Arch Bronconeumol (Engl Ed)"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"410","DOI":"10.1378\/chest.07-0617","article-title":"Comparison of the Sp o 2 \/F io 2 ratio and the PaO2 \/FiO2 ratio in patients with acute lung injury or ARDS","volume":"132","author":"Rice","year":"2007","journal-title":"Chest"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"307","DOI":"10.1016\/j.chest.2016.01.003","article-title":"Nonlinear imputation of PaO2\/FiO2 from SpO2\/FiO2 among patients with acute respiratory distress syndrome","volume":"150","author":"Brown","year":"2016","journal-title":"Chest"},{"key":"ref13","doi-asserted-by":"publisher","first-page":"19","DOI":"10.7812\/TPP\/19.113","article-title":"Association between peripheral blood oxygen saturation (SpO2)\/fraction of inspired oxygen (FiO2) ratio time at risk and hospital mortality in mechanically ventilated patients","volume":"24","author":"Adams","year":"2020","journal-title":"TPJ"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"501","DOI":"10.1016\/j.medine.2021.05.010","article-title":"Correlation and validity of imputed PaO2\/FiO2 and SpO2\/FiO2 in patients with invasive mechanical ventilation at 2600 m above sea level","volume":"46","author":"Ortiz","year":"2022","journal-title":"Medicina Intensiva (English Edition)"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"176","DOI":"10.4103\/lungindia.lungindia_523_23","article-title":"Correlation of oxygenation indices in invasive mechanical ventilated adult patients","volume":"41","author":"Jain","year":"2024","journal-title":"Lung India"},{"key":"ref16","first-page":"000113","volume-title":"Accuracy of SpO","author":"Diao","year":"2021"},{"key":"ref17","doi-asserted-by":"publisher","first-page":"12","DOI":"10.1016\/S2213-2600(14)70238-3","article-title":"High-altitude medicine","volume":"3","author":"West","year":"2015","journal-title":"Lancet Respir Med"},{"key":"ref18","first-page":"232","article-title":"Clinical research on acute respiratory distress syndrome: current status and challenges","volume":"46","author":"Luo","year":"2025","journal-title":"Med J Wuhan Univ"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"5981","DOI":"10.3390\/jcm13195981","article-title":"Impact of inhaled nitric oxide (iNO) on the outcome of COVID-19 associated ARDS","volume":"13","author":"Stoll","year":"2024","journal-title":"JCM"},{"key":"ref20","doi-asserted-by":"publisher","first-page":"1477","DOI":"10.1378\/chest.15-0169","article-title":"Clinical characteristics and outcomes are similar in ARDS diagnosed by oxygen saturation\/F io 2 ratio compared with PaO2 \/FiO2 ratio","volume":"148","author":"Chen","year":"2015","journal-title":"Chest"},{"key":"ref21","doi-asserted-by":"publisher","first-page":"456","DOI":"10.1186\/s12916-023-03144-7","article-title":"The impact of the new acute respiratory distress syndrome (ARDS) criteria on Berlin criteria ARDS patients: a multicenter cohort study","volume":"21","author":"Zhao","year":"2023","journal-title":"BMC Med"},{"key":"ref22","doi-asserted-by":"publisher","first-page":"205","DOI":"10.3390\/jcm7080205","article-title":"The value of oxygenation saturation index in predicting the outcomes of patients with acute respiratory distress syndrome","volume":"7","author":"Chen","year":"2018","journal-title":"JCM."},{"key":"ref23","doi-asserted-by":"publisher","first-page":"198","DOI":"10.4103\/mgr.MEDGASRES-D-24-00101","article-title":"Non-invasive detection of early-stage lung cancer through exhaled breath volatile organic compound analysis","volume":"15","author":"Binson","year":"2025","journal-title":"Medical Gas Res"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"e001475","DOI":"10.1136\/bmjresp-2022-001475","article-title":"Clinical characteristics of patients with a risk of pulmonary artery hypertension secondary to ARDS in a high-altitude area","volume":"10","author":"Zhu","year":"2023","journal-title":"BMJ Open Resp Res"},{"key":"ref25","first-page":"108","article-title":"Risk stratification using SpO2\/FiO2 and PEEP at initial ARDS diagnosis and after 24 h in patients with moderate or severe ARDS","volume-title":"Ann Intensive Care","author":"Pisani","year":"2017"},{"key":"ref26","first-page":"1007","article-title":"Exploration of the relationship between SpO2\/FiO2 and PaO2\/FiO2 in Xining","volume":"18","author":"Wang","year":"2024","journal-title":"Qinghai Chinese J Clinic"},{"key":"ref27","doi-asserted-by":"publisher","first-page":"28","DOI":"10.1016\/j.lers.2025.01.001","article-title":"A comprehensive step-by-step approach for the implementation of target trial emulation: evaluating fluid resuscitation strategies in post-laparoscopic septic shock as an example","volume":"8","author":"Yang","year":"2025","journal-title":"Laparosc Endosc Robot Surg"},{"key":"ref28","doi-asserted-by":"publisher","first-page":"16","DOI":"10.1016\/j.lers.2024.02.001","article-title":"Identification of clinical subphenotypes of sepsis after laparoscopic surgery","volume":"7","author":"Yang","year":"2024","journal-title":"Laparosc Endosc Robot Surg"}],"container-title":["Frontiers in Medicine"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmed.2026.1774390\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,7]],"date-time":"2026-05-07T05:42:06Z","timestamp":1778132526000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fmed.2026.1774390\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,7]]},"references-count":28,"alternative-id":["10.3389\/fmed.2026.1774390"],"URL":"https:\/\/doi.org\/10.3389\/fmed.2026.1774390","relation":{},"ISSN":["2296-858X"],"issn-type":[{"value":"2296-858X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,7]]},"article-number":"1774390"}}