Track and trigger - can improved patient monitoring reduce cardiac arrests in hospitals?

Mrs Brown, a 50 year old woman attended her local A&E with flu-like symptoms and fever. Following some simple investigations she was discharged home with a diagnosis of viral illness. As the symptoms continued she re-presented 48 hours later and this time her blood tests showed evidence of a bacterial infection. Delays in instigating antibiotic and fluid treatment culminated in a cardiac arrest on the ward eight hours later and subsequent death from sepsis related to a perforated appendix.

Could her death have been avoided?

Resuscitation teams are called to around 20,000 cardiac arrests in hospitals across England each year of whom 15% will leave the hospital alive.

Like Mrs Brown, a substantial proportion will have shown signs of deterioration beforehand that were not acted on by staff. Up to one third of the 12 000 preventable deaths in hospitals each year in England are associated with failures of monitoring.

Improving timely assessment and response to deterioration is a priority for the NHS. The introduction of track-and-trigger systems (TTSs) to hospital wards over the past decade aim to help staff track a range of physiological observations to create scores which trigger requests for support.

Following concerns over the proliferation of different TTS, the Royal College of Physicians developed a standard version for the NHS, the National Early Warning Score (NEWS) which was introduced in 2012. The aim was to ensure familiarity across NHS acute hospitals and improve consistency in the assessment and response to acutely ill patients as staff move round the system.

Importantly, use of NEWS has been shown to improve the detection of people with sepsis, allowing the possibility of earlier treatment. Many hospitals are now using digital forms of the original paper tool. These have the added advantage of more accurate scoring and, in some cases, automatic messaging of the patient’s wider medical team when deterioration is detected, reducing delays in response further.

So far, evidence of the association between TTS, such as NEWS, and a reduction in hospital cardiac arrests has been inconsistent, but new research led by the London School of Hygiene & Tropical Medicine has provided important new insight.

Published in the journal HS&DR the research shows that NEWS is associated with reductions in cardiac arrest rates of 8% per year in hospitals. A similar sized benefit was found when hospitals changed from a paper to an electronic version of the tool.

This association highlights the benefits of ward staff recognising patient deterioration earlier and subsequent prompt action, including providing simple treatments such as oxygen therapy or asking for an outreach team assessment. It is likely that such reviews also provide an opportunity to consider if cardiopulmonary resuscitation (CPR) is in the best interests of the patient.

Important questions remain, including which elements of the TTS are most important in improving outcomes. This may be increased staff familiarity with a single tool, accurate score calculation or rapid automatic alerting. Such knowledge would help determine the degree of added value that electronic tools might bring to reducing patient harm associated with deterioration compared with paper-based TTSs.

Our findings do not provide a clear picture on the best configuration for responding to a TTS alert, specifically the value of having a mobile team of staff with critical care skills. However by ensuring it is prompt, standardised track-and-trigger systems such as NEWS seem be saving lives. The findings also represent another example of the benefits for patient safety of standardisation in key areas of clinical practice.

The new NHS Long Term Plan includes managing patients requiring urgent care over a wider range of healthcare settings, such as patients’ homes, and ensuring access to rapid assessment and diagnosis at the front door of hospitals to avoid unnecessary admissions. The availability of a robust tool that allows staff, no matter where they are in the system, to quickly identify which patients might be in need of critical care will be essential.

Further research is required to see if TTS’s such as NEWS could create further positive headlines across the wider healthcare system.


Hogan H, Hutchings A, Wulff J, Carver C, Holdsworth E, Welch J, Harrison D and Black N. Interventions to reduce mortality from in-hospital cardiac arrest: a mixed-methods study. HS&DR Journal. DOI: 10.3310/HSDR07020

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