Pulse oximetry

Tutorial presented by Tanya Howells, Respiratory Nurse Specialist, HDUHB.

Severe COVID-19 infection causes oxygenation failure. Emerging evidence suggests that people may not present with breathlessness despite significant hypoxaemia. If uncertain, a low threshold for pulse oximetry is advised.

Taking an SpO2 measurement from a patient should follow these simple steps to ensure the test result is accurate and a true reflection of their oxygenation status:

  • The patient is rested and calm.
  • The finger is warm, well perfused and there is no nail varnish on the sample site.
  • The oxygen probe is applied to a finger for at least 30 seconds to stabilise, but preferably for the duration of the consultation to ensure the patient is fully rested.

The SpO2 result, together with the patient’s risk criteria (age, co-morbidities, BAME) categorises patients into three risk categories:

Low risk

  • SpO2 greater than or equal to 95%, AND under age 65 with no co-morbidities

Moderate risk

  • SpO2 more than 92% but less than 95%, OR over age 65/under age 65 with co-morbidities, BAME

High risk

  • SpO2 less than or equal to 92%, OR SpO2 less than 88% (or more than 5% below their normal baseline) in any patient with an underlying diagnosis of COPD (or other respiratory disease)

In-person assessment

The Point-of-Care COVID Test

Mark as Understood


All Wales Guideline for the Management of patients with confirmed or suspected COVID-19 in the Community

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