Using pulse oximetry to monitor COVID-19 patients at home

Image of a pulse oximetry device on someone's finger

The beginning of the COVID-19 pandemic was riddled with clinical uncertainty. Technologies which could be used to monitor patients at home such as pulse oximeters were widely adopted by patients. But how safe is it to use a pulse oximeter at home when you have COVID-19? In this blog, we share IGHI’s experiences of being part of the COVID-19 Oximetry at Home Programme. This blog was written by Meesha Patel (Communications and Events Officer, IGHI) and Dr Ahmed Alboksmaty (former Research Associate, IGHI).

At the start of the pandemic, health professionals started spotting unusual symptoms in people who were being admitted to hospital with severe COVID-19. Some people, who had tested positive for the virus and believed they were not having difficulty breathing, were still being admitted to hospital with low oxygen levels. Low levels of oxygen can result in patients being seriously unwell, lengthening their hospital stay, and even threatening their lives.

At the time, the shift to remote appointments made breathlessness and changes in the blood oxygen level due to COVID-19 extremely difficult to spot early for health professionals. Suppose a patient in a remote consultation did not complain of difficulty breathing or any other related symptoms. In this case, health professionals could be led to believe a patient was not seriously ill or suffering from reduced oxygen.

“During the pandemic, people ill with COVID-19 started buying and using oximeters to report their oxygen levels to health care professionals. This allowed clinicians to decide if a patient needed to be seen further…”

One way to overcome this became the use of pulse oximeters. These devices are worn over a patient’s finger to detect oxygen levels in the blood, displayed as a percentage. Before the pandemic, oximeters were used widely in health care settings such as hospitals and care homes but not commonly used at home. But during the pandemic, people ill with COVID-19 started using oximeters to report their oxygen levels to health care professionals. This allowed clinicians to decide if a patient needed to be seen further and receive more urgent care by emergency services.

Programmes started to spring up locally, which were often quite different to another. Sometimes people ran community groups which had access to these devices, and sometimes these programmes were run by GPs and nursing teams. However, there was a need for evidence about how oximeters were used to see if they were first, effective and safe and second, accurate and reliable.

IGHI’s involvement in the COVID Oximetry at Home Programme

The Institute of Global Health Innovation’s (IGHI’s) involvement began in 2020 when we evaluated four programmes which used Covid Oximetry monitoring at home, in partnership with NHS Digital. We wanted to understand what these programmes were doing, and what sort of people were using oximeters. Overall, we found the four programmes were safe, and we learnt how these devices were used during the pandemic at that point in time.

In November 2020, NHS England then created the national COVID Oximetry at Home (CO@H) programme where all Clinical Commissioning Groups (CCGs) were recommended, but not required, to provide oximeters to the community by general practice teams.

In most cases, this meant a patient who had COVID-19 would be given a pulse oximeter which they used to measure their oxygen levels over two weeks. If their oxygen levels hadn’t decreased, then they were considered safe and no longer included in the monitoring programme. People who were eligible for this programme were over the age of 50+ or identified as clinically extremely vulnerable and could be supported by carers or family members to take the readings if needed.

IGHI was one of a wider team of research centres which were tasked with evaluating oximeters for the use of COVID-19. We conducted the first extensive evidence review of pulse oximetry and its potential for home monitoring for people with COVID-19. The review screened 561 relevant publications on the topic and finally included the most relevant 13 studies involving almost 3,000 participants across five countries (UK, US, Singapore, Brazil and Australia).

Is using a COVID-19 pulse oximeter safe?

Our review, which was published in Lancet Digital Health, looked at how safe and effective it is to use Oximetry devices for COVID-19. Overall, we found that it was safe to use an Oximetry device as a guide at home to check if a patient needed emergency or hospital admission.

Our paper also looked at the way Oximetry devices were used, and we suggested three recommendations:

  1. Oxygen levels should be measured when ‘at rest’ and after completing some form of exercise. This is because a person could display normal levels when not exercising but as soon as they do start moving around, their levels could drop dramatically which may be dangerous and need emergency care.
  2. The definition of ‘at rest’ in most studies was when a patient has been resting for between 5 to 10 minutes.
  3. A 92% oxygen level in blood is the minimum level a patient should have and still be relatively safe. If the oxygen level falls below this, then the patient should go to emergency care immediately. However, if there is a 5% drop at any time (from at rest to after exercise for example) then this could also be an emergency. Some patients with chronic medical conditions may have different thresholds for safety.

The future of pulse oximetry devices

In the future the question won’t be ‘do I have COVID-19?’ but ‘if I have COVID-19 do I need to go to hospital?’. Oximetry devices are widely available, easy to use and priced around £15-£30. This is key for their adoption in other health systems. Countries with limited resources and limited availability of COVID testing can recommend self-monitoring at home by pulse oximeters, which can potentially save resources and improve health outcomes among patients with COVID-19.

A major limitation of our work however is that we didn’t explore how oximeters work on people with different skin colours. Recent evidence shows that oximeters may not be as effective for minority ethnic groups and organisations such as NHS Race and Health Observatory and NIHR have further research work planned in this area. There is also a need for research in the use of devices by people with peripheral vascular diseases as this could affect the accuracy of their oximetry readings as well.

“Countries with limited resources and limited availability of COVID testing can recommend self-monitoring at home by pulse oximeters, which can potentially save resources and improve health outcomes among patients with COVID-19.”

What we do know is that the pandemic is not over yet. In the UK, we are free from restrictions for now, but we should be mindful that in limited resource settings, there may not always be a way to tell if a person has COVID-19. A tool such as an oximeter, which is affordable and monitors patients at home, could have the potential for a wide impact on reducing the burden on international health systems.

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