Doctors made three important discoveries during the first wave of the pandemic. First that patients could be feeling fine and showing no outward signs of illness but still have dangerously low oxygen levels, a condition known as silent hypoxia.
Second that oxygen levels on their own were highly predictive of deterioration in COVID-19, regardless of other symptoms.
Their third discovery was that the threshold for giving patients supplemental oxygen in covid-19 is much higher than that used in most western countries during the first wave. It needs to be considered when patients’ oxygen levels have fallen to around 94%, rather than as low as 92 or even 91%, as previously thought.
They have taken this learning and combined it with giving patients pulse oximeters to record their own oxygen levels. Patients are then monitored remotely via phone consultations and digital apps in ‘covid virtual wards’ creating an early warning system for covid-19, which doctors have been piloting in projects around the country.
The pilots have started to yield impressive results, with one validated study showing a mortality rate of 1% among high-risk patients, compared with an overall mortality rate in the UK of more than 14% in the first wave. The plan now is to translate the better outcomes to more parts of the country.
As we battle the second wave, the covid early warning system is now
being implemented around the country through clinical commissioning groups (CCGs).
Dr Matt Inada-Kim, a consultant in acute care medicine at Hampshire Hospitals and the national clinical lead for deterioration and sepsis for NHS England, was involved in a large pilot, in the Wessex region, and worked on the national strategy.
He says the goal of the Covid Early Warning System is to identify people with low oxygen saturations and other signs of deterioration early so they can be treated sooner and more lives saved.
But catching people early has to happen in the community, while they are still at home and when their oximetry readings drop by 1-2%, before hypoxia sets in. That cannot be a hospital-led initiative, says Dr Inada-Kim. And it is why the Covid Early Warning System strategy will rely heavily on nurses, paramedics and care assistants as well as GPs and hospital doctors.
On this site Dr Inada-Kim presents the evidence for oxygen levels being the early sign of deterioration in covid-19 and describes why community healthcare practitioners need to monitor people for silent hypoxia. He also shows GPs, nurses and paramedics how this can be done on a community-wide scale while keeping patients safeguarded at home in the covid virtual ward.