A review of early warning systems for prompt detection of patients at risk for clinical decline

Abstract

Early Warning Scores (EWS) are a composite evaluation of a patient's basic physiology, changes of which are the first indicators of clinical decline and are used to prompt further patient assessment and when indicated intervention. These are sometimes referred to as “track and triggers systems” with tracking meant to denote periodic observation of physiology and trigger being a predetermined response criteria. This review article examines the most widely used EWS, with special attention paid to those used in military and trauma populations. The earliest EWS is the Modified Early Earning Score (MEWS). In MEWS, points are allocated to vital signs based on their degree of abnormality, and summed to yield an aggregate score. A score above a threshold would elicit a clinical response such as a rapid response team. Modified Early Earning Score was subsequently followed up with the United Kingdom's National Early Warning Score, the electronic cardiac arrest triage score, and the 10 Signs of Vitality score, among others. Severity of illness indicators have been in military and civilian trauma populations, such as the Revised Trauma Score, Injury Severity Score, and Trauma and Injury Severity. The sequential organ failure assessment score and its attenuated version quick sequential organ failure assessment were developed to aggressively identify patients near septic shock. Effective EWS have certain characteristics. First, they should accurately capture vital signs information. Second, almost all data should be derived electronically rather than manually. Third, the measurements should take into consideration multiple organ systems. Finally, information that goes into an EWS must be captured in a timely manner. Future trends include the use of machine learning to detect subtle changes in physiology and the inclusion of data from biomarkers. As EWS improve, they will be more broadly used in both military and civilian environments. LEVEL OF EVIDENCE Review article, level I.

The utility of MEWS for predicting the mortality in the elderly adults with COVID-19: a retrospective cohort study with comparison to other predictive clinical scores

“…Modified Early Warning Score consists of 5 physiological parameters, which include systolic blood pressure, pulse rate, respiratory rate, temperature, and level of consciousness. It has been used as an essential tool for early identification of patients who can deteriorate in medical and surgical wards (Fullerton et al, 2012;Kramer, Sebat & Lissauer, 2019;Salottolo et al, 2017). Some studies have shown that a MEWS score of 5 or above is associated with a high risk of poor outcome in intensive care unit (Reini, Fredrikson & Oscarsson, 2012).…”

Prehospital Point-Of-Care Lactate Increases the Prognostic Accuracy of National Early Warning Score 2 for Early Risk Stratification of Mortality: Results of a Multicenter, Observational Study

“…The current recommendations of the Royal College of Physicians of London [6] set thresholds and triggers. An aggregate score of 7 or more indicates high risk that demands the response of the critical care team [36]. With this strict criterion for activating the emergency response, health systems ensure that no ill person is at risk of mortality and of suffering SAEs.…”

Identification of Serious Adverse Events in Patients with Traumatic Brain Injuries, from Prehospital Care to Intensive-Care Unit, Using Early Warning Scores

“…Works analyzing the use of EWS in a prehospital setting are numerous [14,15,30,31] and more specifically concern the use of EWS in patients with trauma [32][33][34][35]. Studies that specifically analyse scores to predict the risk of deterioration in TBI are scarce.…”

“…The regular assessment of the risk of deterioration through EWS is a standard procedure in multiple clinical context the use of which is more than contrasted [14,15,28] and which can help to detect patients with TBI and a high risk [49,50]. Determining which patients may be subsidiaries of advanced procedures and rapid transportation to a useful center must be a priority for the EMS [51].…”

“…The use of EWS in patients with major trauma is well-documented in clinical practice [13][14][15]. Similarly, the Glasgow Coma Scale (GCS) is normally used to establish the severity of the TBI [16][17][18].…”