key: cord-0732818-pb8p5ekn
authors: Wilson‐Baig, N.; McDonnell, T.; Bentley, A.
title: Discrepancy between S(p)O(2) and S(a)O(2) in patients with COVID‐19
date: 2020-08-01
journal: Anaesthesia
DOI: 10.1111/anae.15228
sha: 2a5e30c9a525b2c97dbbdbc6cee3493de9d41234
doc_id: 732818
cord_uid: pb8p5ekn

nan

In patients admitted to our critical care unit during the COVID-19 pandemic, we observed that oxygen saturation measured by pulse oximetry (S p O 2 ) was consistently lower than arterial oxygen saturation (S a O 2 ) measured directly by blood gas analysis. Pulse oximetry is a simple, cheap and non-invasive method of measuring S p O 2 . The pulse oximeter consists of two light-emitting diodes which transmit light at two wavelengths; 660 nm and 940 nm, and a photodetector that is sited across a tissue bed, for example, a finger. It is assumed that absorbance at these wavelengths is due to de-oxyhaemoglobin or oxyhaemoglobin [1] . The accuracy of pulse oximeters is generally quoted as AE2%' [1] 

Pulse oximetry: fundamentals and technology update

Do changes in pulse oximeter oxygen saturation predict equivalent changes in arterial oxygen saturation?

Comparative evaluation of accuracy of pulse oximeters and factors affecting their performance in a tertiary intensive care unit

Pulse oximetry: understanding its basic principles facilitates appreciation of its limitations

Increased blood glycohemoglobin A1c levels lead to overestimation of arterial oxygen saturation by pulse oximetry in patients with type 2 diabetes

Hemoglobin lansing: a novel hemoglobin variant causing falsely decreased oxygen saturation by pulse oximetry

The authors thank M. Columb for reviewing our statistics. No competing interests declared.