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Abstract

We thank Drs Lellouche and L’Her for their comments on our retrospective study of oxygen saturation targets in the ICU.1van den Boom W. Hoy M. Sankaran J. et al.The search for optimal oxygen saturation targets in critically ill patients: observational data from large ICU databases.Chest. 2020; 157: 566-573Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar In our study, adherence to a pulse oximetry-derived oxygen saturation (Spo2) target of 94% to 98% was associated with reduced mortality. At the same time, 80% adherence to the Spo2 target was observed in only 5% and 7% of the cases, respectively, in the two databases that we analyzed. Therefore, our results support the use of automated closed-loop oxygen titration2Lellouche F. Bouchard P.A. Roberge M. et al.Automated oxygen titration and weaning with FreeO2 in patients with acute exacerbation of COPD: a pilot randomized trial.Int J Chron Obstruct Pulmon Dis. 2016; 11: 1983-1990Crossref PubMed Scopus (36) Google Scholar to improve adherence to an Spo2 target. A point of contention is the choice of Spo2 targets in such systems. Our study used a data-driven approach to derive an Spo2 target range of 94% to 98%, but was observational and thus subject to confounding.1van den Boom W. Hoy M. Sankaran J. et al.The search for optimal oxygen saturation targets in critically ill patients: observational data from large ICU databases.Chest. 2020; 157: 566-573Abstract Full Text Full Text PDF PubMed Scopus (26) Google Scholar In contrast, randomized trials that have been conducted focused on comparing predefined Spo2 thresholds and did not learn an optimal Spo2 target range from data.2Lellouche F. Bouchard P.A. Roberge M. et al.Automated oxygen titration and weaning with FreeO2 in patients with acute exacerbation of COPD: a pilot randomized trial.Int J Chron Obstruct Pulmon Dis. 2016; 11: 1983-1990Crossref PubMed Scopus (36) Google Scholar, 3Girardis M. Busani S. Damiani E. et al.Effect of conservative vs conventional oxygen therapy on mortality among patients in an intensive care unit: the oxygen-ICU randomized clinical trial.JAMA. 2016; 316: 1583-1589Crossref PubMed Scopus (311) Google Scholar, 4Barrot L. Asfar P. Mauny F. et al.Liberal or conservative oxygen therapy for acute respiratory distress syndrome.N Engl J Med. 2020; 382: 999-1008Crossref PubMed Google Scholar Decisive evidence for an optimal Spo2 range remains absent while the choice of an optimal Spo2 range may have a substantial effect on clinical outcomes.3Girardis M. Busani S. Damiani E. et al.Effect of conservative vs conventional oxygen therapy on mortality among patients in an intensive care unit: the oxygen-ICU randomized clinical trial.JAMA. 2016; 316: 1583-1589Crossref PubMed Scopus (311) Google Scholar Therefore, the introduction of automated oxygen titration should be paired with randomized trials5Self W.H. Semler M.W. Rice T.W. Oxygen targets for patients who are critically ill: emerging data and state of equipoise.Chest. 2020; 157: 487-488Abstract Full Text Full Text PDF PubMed Scopus (1) Google Scholar investigating what Spo2 range should be targeted by such systems. “Protective Oxygen Therapy” for Critically Ill Patients: A Call for Automated Oxygen Titration!CHESTVol. 158Issue 3PreviewWe have read with interest the study from Van den Boom et al1 published in a past issue of CHEST (March 2020). The study provides new perspectives on optimal oxygenation range targets for critically ill patients. van den Boom’s first finding is the U-shaped relationship between arterial oxygen saturation (Spo2) and mortality. This U-shaped relationship was previously documented by several studies.2 The second novel and important point is the inverse relationship between the percentage of time patients were maintained within the oxygenation target and the mortality. Full-Text PDF The Search for Optimal Oxygen Saturation Targets in Critically Ill Patients: Observational Data From Large ICU DatabasesCHESTVol. 157Issue 3PreviewAlthough low oxygen saturations are generally regarded as deleterious, recent studies in ICU patients have shown that a liberal oxygen strategy increases mortality. However, the optimal oxygen saturation target remains unclear. The goal of this study was to determine the optimal range by using real-world data. Full-Text PDF