COVID-19 patients are dying because they have few symptoms and are getting to hospital too late, particularly with Delta. A Sth African study suggests deaths could be “significantly” reduced with oximeters.[0] One reason is that patients at home do not realise their oxygen levels have dropped dangerously low. Hence, in late 2020, NHS England purchased 200,000 pulse oximeters to measure oxygen levels for the more vulnerable among those with coronavirus at home.[1]
In July 2021, Singapore set out to supply every household with an oximeter. They had seen their successful use a year earlier when they gave out 20,000 oximeters to their migrant workers.[2, 2a]
There’s been little mention of oximeters in Australia. More needs to be said, as the trick with COVID is acting early both individually with treatment, and population-wise with isolation.
Earlier Warning System
Imagine more than 650,000 people spread over 2.5 sq km. That is Dharavi, a sprawling slum in the heart of Mumbai that kept COVID relatively at bay for a year. Social distancing is not a luxury people can afford. And density is a friend of the coronavirus.[3] As of 23 August 2021, they were still doing quite well against Covid.[4]
Part of their ongoing success has been the simple measure of checking the inhabitants temperatures and blood oxygen levels. Those who were found to have an issue, were then moved to an isolation centre for a COVID-test, and care.
Both an infrared thermometer and a finger pulse oximeter take minimal time to screen for prospective COVID-cases, and could be used at entrances to all buildings such as shopping centres. While thermometers are used in Australia, mention of oximeters has been lacking.
Wearables
Even more concerning is the lack of consideration of monitoring devices that many of us are already wearing. Smart watches and fitness bands can provide up to 9.5 days notice of flu-like symptoms - read: COVID. They have been used to protect important people like ProAm Golfers and NASA astronauts, but they could just as easily protect so many more of us wearing the same devices, and help with recovery. [4a]
Who? Stan - we’ve had a problem
Recent research demonstrates that some oximeters can underestimate oxygen readings 3 times as often on dark skin, compared to light skin.[5] That means people with dark skin might think they do not need hospitalisation, with tragic consequences.
This was “discovered” again in the US at the end of 2020, with the US Food & Drug Administration (FDA) issuing a Safety Communication in February 2021.[6] The UK also just re-discovered the problem with the BBC reporting on it on 31 July 2021.[7]
The Thoracic Society of Australian and New Zealand Oxygen Guidelines for Acute Oxygen Use In Adults from October 2015, does mention that dark skin as one of the factors “that might affect the accuracy of pulse oximetry”.[8]
However, it would not seem to be widely known, particularly among the general public, who are more likely to be using the cheaper, more unreliable oximeters. Not all oximeters are created equal which is possibly why Apple headhunted 20 of oximeter-leader Masimo’s staff to work at Apple including on the Apple Watch. They are now locked in an all out legal battle including allegations of copying of patents on ways to reduce errors in readings.[9]
The need for greater use of oximeters is undeniable. Just be aware of the potential skin tone problem, and rely on trends in a series of readings, rather than a one-off.
REMOTE COVID SUPPORT, Education + RESEARCH
Sinch Software Pty Ltd provides a SMS-based remote care system to those who get COVID, and are home alone, or with limited support. It enables a remote carer to track your oxygen levels via hourly readings, and be alerted automatically if you deteriorate. It doubles as a training tool with around 100 oximeter use, self-care and recovery tips when confirming receipt for each reading.[10]
To complement the SMS support, we have a 16 page guide on setting up a virtually free remote camera system to monitor and engage with patients or those not strong on IT.[11]
We are also undertaking research to shed light on which oximeters are problematic via a world-wide survey of oximeter users. The more responses we receive, the more likely that we will be able to pick up useful patterns in the data. We intend to share the results to alert users to the need to make adjustments to readings for their oximeter and skin type.[12]