The working accuracy of pulse oximetry in COVID-19 patients stepping down from intensive care: a clinical evaluation
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Introduction
UK Guidelines suggest pulse oximetry, rather than blood gas sampling, is adequate for monitoring of patients with COVID-19 if CO2 retention is not suspected. However, pulse oximetry has impaired accuracy in certain patient groups, and data are lacking on its accuracy in patients with COVID-19 stepping down from Intensive Care Units (ICU) to non-ICU settings or being transferred to another ICU.
Methods
We assessed the bias, precision, and limits of agreement using 90 paired SpO2 and SaO2 from 30 patients (3 paired samples per patient). To assess the agreement between pulse oximetry (SpO2) and arterial blood gas analysis (SaO2) in patients with COVID-19, deemed clinically stable to step down from an ICU to a non-ICU ward, or be transferred to another ICU. This was done to evaluate whether the guidelines were appropriate for our setting.
Results
Mean difference between SaO2 and SpO2 (bias) was 0.4%, with a standard deviation of 2.4 (precision). The limits of agreement between SpO2 and SaO2 were, upper limit of 5.2% (95% CI 6.5 to 4.2), lower limit of -4.3% (CI -3.4 to -5.7).
Conclusions
In our setting, pulse oximetry showed a level of agreement with SaO2 measurement that was slightly sub-optimal, though within acceptable levels for FDA approval, in people with COVID-19 judged clinically ready to step down from ICU to a non-ICU ward, or who were being transferred to another hospital’s ICU. In such patients, SpO2 should be interpreted with caution. Arterial blood gas assessment of SaO2 may still be clinically indicated.
UK Guidelines suggest pulse oximetry, rather than blood gas sampling, is adequate for monitoring of patients with COVID-19 if CO2 retention is not suspected. However, pulse oximetry has impaired accuracy in certain patient groups, and data are lacking on its accuracy in patients with COVID-19 stepping down from Intensive Care Units (ICU) to non-ICU settings or being transferred to another ICU.
Methods
We assessed the bias, precision, and limits of agreement using 90 paired SpO2 and SaO2 from 30 patients (3 paired samples per patient). To assess the agreement between pulse oximetry (SpO2) and arterial blood gas analysis (SaO2) in patients with COVID-19, deemed clinically stable to step down from an ICU to a non-ICU ward, or be transferred to another ICU. This was done to evaluate whether the guidelines were appropriate for our setting.
Results
Mean difference between SaO2 and SpO2 (bias) was 0.4%, with a standard deviation of 2.4 (precision). The limits of agreement between SpO2 and SaO2 were, upper limit of 5.2% (95% CI 6.5 to 4.2), lower limit of -4.3% (CI -3.4 to -5.7).
Conclusions
In our setting, pulse oximetry showed a level of agreement with SaO2 measurement that was slightly sub-optimal, though within acceptable levels for FDA approval, in people with COVID-19 judged clinically ready to step down from ICU to a non-ICU ward, or who were being transferred to another hospital’s ICU. In such patients, SpO2 should be interpreted with caution. Arterial blood gas assessment of SaO2 may still be clinically indicated.
Date Issued
2020-12-23
Date Acceptance
2020-12-07
Citation
BMJ Open Respiratory Research, 2020, 7 (1), pp.1-5
ISSN
2052-4439
Publisher
BMJ Publishing Group
Start Page
1
End Page
5
Journal / Book Title
BMJ Open Respiratory Research
Volume
7
Issue
1
Copyright Statement
© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ. http://creativecommons.org/licenses/by-nc/4.0/
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/.
License URL
Sponsor
Imperial College London
Identifier
https://bmjopenrespres.bmj.com/content/7/1/e000778
Subjects
Science & Technology
Life Sciences & Biomedicine
Respiratory System
respiratory measurement
respiratory measurement
Adult
Aged
COVID-19
Critical Care
Female
Follow-Up Studies
Humans
Intensive Care Units
Male
Middle Aged
Oximetry
Oxygen
Reproducibility of Results
Retrospective Studies
SARS-CoV-2
Humans
Oxygen
Oximetry
Critical Care
Retrospective Studies
Follow-Up Studies
Reproducibility of Results
Adult
Aged
Middle Aged
Intensive Care Units
Female
Male
COVID-19
SARS-CoV-2
Publication Status
Published
Date Publish Online
2020-12-23