| Property | Value |
|---|
|
?:abstract
|
-
ABSTRACT. Patients in the UK at risk of Covid-19 pneumonia, but not needing immediate hospital attention, are to be given pulse oximeters to identify at home deterioration in oxygen saturation (SaO2 or SpO2). A recent finding in Covid-19 pneumonia is a dominant reduction in VA/Q. A mathematical model of gas exchange was used to examine the effect of reduction of VA/Q or increase in shunt on SaO2 stability inferred from the slope of the PIO2 vs SaO2 curve as it intersects the line representing ambient PIO2. Reduced VA/Q predicted SpO2 instability breathing air, e.g. a {+/-}1 kPa change in PIO2 gave an 8% change in SpO2 at a VA/Q of 0.4 but a 1.5% change in SpO2 with a 15% shunt. As a consistency check, two patients with pre-existing lung disease and 12 hour continuous SpO2 monitoring breathing air had gas exchange impairment analysed in terms of shunt and reduced VA/Q. The patient with 16% shunt and normal VA/Q had a stable but reduced SpO2 (circa 93%) throughout the 12 hr period. The patient with a VA/Q reduced to 0.48 had SpO2 ranging from 75-95% during the same period. SpO2 monitoring in suspected covid-19 patients should focus on SpO2 varying >5% in 30 minutes. Such instability in at risk patients is not diagnostic of Covid -19 pneumonia but this may be suspected from a dominant reduction in VA/Q if episodic hypoxaemia has progressed from a stable SpO2. Key words. Covid-19, Respiratory Measurement, Pneumonia, ARDS, VA/Q, Shunt, Oxygen Saturation.
|
|
is
?:annotates
of
|
|
|
?:creator
|
|
|
?:doi
|
|
|
?:doi
|
-
10.1101/2020.12.17.20248126
|
|
?:license
|
|
|
?:pdf_json_files
|
-
document_parses/pdf_json/db6a473bf6df09582a7e0195293928c7ad802557.json
|
|
?:publication_isRelatedTo_Disease
|
|
|
?:sha_id
|
|
|
?:source
|
|
|
?:title
|
-
Oxygen saturation instability in suspected covid-19 patients; contrasting effects of reduced VA/Q and shunt.
|
|
?:type
|
|
|
?:year
|
|
![[This page as RDF]](https://research.tib.eu/covid-19/static/rdf-icon.gif){kind=icon}