A national early warning score for acutely ill patients

The critical care unit, which clusters patients with life threatening illness in a single geographical area, is now a familiar concept. It offers patients the best chance of survival through optimum technology and the concentration of clinical skills and experience. Critical care medicine is a specialty that depends largely on a resource intensive environment. Until recently, for both economic and practical reasons, critical care could not be provided for every hospital inpatient. As the specialty has developed, it has repeatedly been noted that poor outcomes commonly result from a failure to promptly recognise and treat patients who become acutely ill on a standard hospital ward. As part of a long term strategy to tackle this problem, the Royal College of Physicians has launched a national early warning score.1 This is a welcome development that may be good news for patients. However, it is worth highlighting some potential pitfalls.

Patients die not from their disease but from the disordered physiology caused by the disease. The early warning score is an established tool that uses this concept to identify patients at risk. Points are allocated according to basic clinical observations including pulse rate, respiratory rate, blood pressure, oxygen saturation, and level of consciousness. The higher the score the more likely it is that the patient is developing a critical illness (figure⇓)). A high score prompts healthcare staff to request a detailed clinical assessment, which should result in an early and effective treatment plan. In the United Kingdom, most hospitals already use a locally developed early warning score. In many cases, such tools were derived in response to a national review of critical care services, which set out a strategy to provide an integrated system-wide approach to the care of critically ill patients.2 This review emphasised that an adequate standard of care should be provided to all patients regardless of their geographical location within the hospital, and it ushered in the concept of “critical care without walls.” To save lives an early warning score system must be linked to an effective clinical response. Nurse led critical care outreach teams are common in UK hospitals, although in other countries a physician led medical emergency team approach has been adopted.

National early warning score and classification of clinical risk

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The effectiveness of the twin concepts of early warning scores and critical care without walls has been debated. An institutional level response of this type obliges clinicians to adopt a new system that is not entirely of their choosing. An increase in workload for critical care staff as they take responsibility for patients throughout the hospital may seriously affect the provision of care within critical care units. Some commentators have expressed concern about the limited evidence to justify critical care outreach services.3 The evidence base is indeed inconsistent in this area; early positive studies provided grade C evidence, which has not been confirmed by more robust research.4 5 6 Nonetheless, the impact of the “failure to rescue” critically ill patients in the ward environment is undeniable.7 Critical care outreach does not seem to have been widely implemented internationally, but in the UK at least, this system seems here to stay.8

It is increasingly clear that tackling variations in quality of care improves patient outcomes. The idea is to eliminate poor care by bringing all services up to a minimum standard. One of the strengths of the NHS in the UK is the ability to implement top down strategies to provide a consistent standard of patient care where definitive evidence may never be forthcoming. The rapid and complete implementation of the World Health Organization safer surgery checklist is just one example.9 If the critical care outreach concept is to be developed further, it makes sense to implement the national early warning score in the same way. Members of staff who move between hospitals will then find a similar approach to patient monitoring and a similar response to the deteriorating patient in each location. Institutions where critical care outreach is not fully developed will seek to raise standards to the national level and will probably come under pressure to do so. The opportunity for general practitioners and pre-hospital care staff to use the early warning score could create a simple common language to describe the severity of acute illness across the UK’s healthcare system.

It is essential to achieve a careful balance between national standards and local priorities, however, because a good idea that is badly implemented can have a negative effect. Patient groups characterised by abnormal physiology, such as those with end stage renal failure, or patients recovering from brain injury, may present particular difficulties. Implementation of the early warning score requires a thoughtful pilot phase, which should include a validation of the trigger thresholds that activate a response. Wider implementation will require adequate staff training and a sensitive approach when restructuring established systems that already work well. Meanwhile, frontline NHS staff must work positively to ensure the new system is effective. Only then can we establish whether a national early warning score is good news for patients.