TY - JOUR T1 - Oximetry neither to prescribe long-term oxygen therapy nor to screen for severe hypoxaemia JF - ERJ Open Research JO - erjor DO - 10.1183/23120541.00272-2021 SP - 00272-2021 AU - Yves Lacasse AU - Sébastien Thériault AU - Benoît St-Pierre AU - Sarah Bernard AU - Frédéric Sériès AU - Harold Jean Bernatchez AU - François Maltais Y1 - 2021/01/01 UR - http://openres.ersjournals.com/content/early/2021/07/29/23120541.00272-2021.abstract N2 - Background and Objective Transcutaneous pulse oximetry saturation (SpO2) is widely used to diagnose severe hypoxaemia and to prescribe long-term oxygen therapy (LTOT) in chronic obstructive pulmonary disease (COPD). This practice is not based on evidence. The primary objective of this study was to determine the accuracy (false positive and false negative rates) of oximetry for prescribing LTOT or for screening for severe hypoxaemia in patients with COPD.Methods In a cross-sectional study, we correlated arterial oxygen saturation (SaO2) and SpO2 in patients with COPD and moderate hypoxaemia (n=240), and calculated the false positive and false negative rates of SaO2 at the threshold of ≤88% to identify severe hypoxaemia (PaO2 ≤55 mmHg or PaO2 <60 mmHg) in 452 patients with COPD with moderate or severe hypoxaemia.Results The correlation between SaO2 and SpO2 was only moderate (intra-class coefficient of correlation: 0.43; 95% confidence interval: 0.32–0.53). LTOT would be denied in 40% of truly hypoxemic patients on the basis of a SaO2 ˃ 88% (i.e., false negative result). Conversely, LTOT would be prescribed on the basis of a SaO2≤88% in 2% of patients who would not qualify for LTOT (i.e., false positive result). Using a screening threshold of≤92%, 5% of severely hypoxemic patients would not be referred for further evaluation.Conclusions Several patients who qualify for LTOT would be denied treatment using a prescription threshold of saturation ≤88% or a screening threshold of ≤92%. Prescription of LTOT should be based on PaO2 measurement.FootnotesThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online. Please open or download the PDF to view this article.Conflict of interest: Dr. Lacasse has nothing to disclose.Conflict of interest: Dr. Thériault has nothing to disclose.Conflict of interest: Dr. St-Pierre has nothing to disclose.Conflict of interest: Dr. Bernard has nothing to disclose.Conflict of interest: Dr. Sériès has nothing to disclose.Conflict of interest: Dr. Bernatchez has nothing to disclose.Conflict of interest: Dr. Maltais has nothing to disclose. ER -