Case study: Ambulance data leads the way for coronavirus clinical assessment and patient monitoring
In this interview, Dr John Black discusses the ambulance data behind the rollout of the COVID Oximetry @home initiative.
Since 2010 I have been Medical Director at South Central Ambulance Service (SCAS) alongside my role as Consultant in Emergency Medicine at Oxford University Hospitals NHS Foundation Trust.
Much of my work has involved assessing acutely ill and injured patients to make sure they receive the best possible treatment in the right setting. Time is of the essence in an emergency. This is always a challenge, but with the emergence of COVID-19 early in 2020 our work in emergency care took on even greater significance.
In emergency care and medicine we know a lot about how important vital signs are in patients and how they can often indicate more serious conditions. But learning how to adapt rapidly to a new virus presented the ambulance service with a real test of our abilities and capacity to learn as fast as we could.
Like most medical professionals, we were having to absorb vast amounts of information, from many healthcare settings, that changed on a daily basis. These helped to inform our decisions on how to care for individuals needing ambulance services with suspected or confirmed coronavirus.
Traditionally, emergency departments and ambulance services use the National Early Warning Score (NEWS 2) which allows us to assess a patient’s immediate health by taking six key physiological measurements (respiration rate, oxygen saturation, systolic blood pressure, pulse rate, level of consciousness or confusion and temperature) and we have various ranges that are considered normal.
This joined-up approach and shared endeavour to help fight this disease has demonstrated what the NHS is capable of delivering when faced with an unprecedented national emergency and we should all take pride in what has collectively been achieved and how the NHS has coped during the last 18 months.
But after analysing ambulance data that we were collecting among patients with COVID-19, it showed that just a slight drop in oxygen saturation levels, frequently observed in patients with mild symptoms and which we would usually consider as being at the low end of the normal range (SpO2 95% or less) in non-COVID disease, was an important signal for significant risk of deterioration and correlated with the need for intensive care and mortality.
Oxygen saturations alone were the most reliable single predictor of deterioration in our patient cohort. Another early, and important, clinical observation was that many patients with profoundly reduced oxygen saturations had very little, if any, symptoms of breathlessness.
Usually, we would expect breathlessness to appear much earlier in the disease progression, but with COVID-19 this wasn’t the case. This is likely to have resulted in patients/carers and potentially healthcare professionals not appreciating the severity of their illness and may have contributed to the high mortality observed in the first wave of the pandemic in the UK.
These were very significant findings for the ambulance service because it confirmed that we needed to refine and adapt ambulance clinical assessment tools for this novel disease to guide clinicians as to when emergency admission to hospital was required and when further monitoring and follow-up in the community was appropriate.
Armed with this knowledge, and with funding from NHS England, SCAS became the first ambulance service to issue patients with pulse oximeter packs, which included symptom diaries and written instructions for patients with COVID-19 that did not require immediate admission to hospital.
Our paramedics were able to directly refer these patients onto Oximetry@Home ‘virtual wards’ for further monitoring and follow up by primary and secondary care. Offering this solution to patients added a duality to their care – they could monitor themselves and be monitored by health professionals prompting faster action in the event of deterioration.
The pandemic has created great opportunities for NHS clinical research, and it is particularly important that the ambulance service continues to develop its capacity to support this.
The insights we have gained have also allowed us to develop an assessment tool in conjunction with NHS England to help ambulance services further refine how they assess patients with COVID-19 and alert them to potential risk factors that need closer monitoring.
I’ve been working closely with my colleagues in the National Ambulance Service Medical Directors (NASMeD) team to roll out the COVID Assessment Tool to other ambulance services across the UK.
These tools will also be essential for health care support workers with minimal clinical training (in nursing and care homes for example). By providing them with a simple, evidence-based process for clinical assessment they will be able to call for help earlier for patients that are deteriorating and help to save lives.
The pandemic has created great opportunities for NHS clinical research, and it is particularly important that the ambulance service continues to develop its capacity to support this. SCAS research capacity has increased significantly with the support of the NIHR and Wessex and Thames Valley and South Midlands Clinical Research Networks during the last three years, enabling us to collaborate with many different elements of the NHS.
This joined-up approach and shared endeavour to help fight this disease has demonstrated what the NHS is capable of delivering when faced with an unprecedented national emergency. We should all take pride in what has collectively been achieved and how the NHS has coped during the last two years.
Beyond this, ambulance clinical datasets for all emergency and urgent care diagnoses have immense value when integrated and analysed with health and care providers' coding and outcome data as COVID-19 has demonstrated. The more that can be done collectively in partnership to analyse our clinical datasets across healthcare systems for entire patient pathways, the better the prospects will be for successfully responding to and, ultimately containing, this devastating disease.
The much quoted global health aphorism that ‘none of us are safe until we are all safe’ remains relevant for us all for the foreseeable future.