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A 3-year-old boy presents to his local district general hospital with a 1-day history of fever and shortness of breath. He is admitted to the paediatric ward for ongoing observation and management. The nursing staff calculate a paediatric early warning score (PEWS), based on physiological parameters, with each set of nursing observations. The student nurse on the ward notices that your chart is different from the one used by the paediatric ward on her last placement. She asks you how accurately paediatric early warning scoring systems predict serious clinical deterioration, particularly cardiopulmonary arrest (CPA), paediatric intensive care admission or paediatric high-dependency care admission.
In paediatric inpatients, can a paediatric early warning trigger or scoring system predict serious clinical deterioration?
Medline 1950 to present from PubMed
Cochrane Library Issue 9, September 2014
Search terms used: ((‘pediatrics’[MeSH Terms] OR ‘pediatrics’[All Fields] OR ‘paediatric’[All Fields]) OR (‘pediatrics’[MeSH Terms] OR ‘pediatrics’[All Fields] OR ‘pediatric’[All Fields])) AND (early[All Fields] AND warning[All Fields]) AND ((‘Sentinel Event Alert’[Journal] OR ‘alert’[All Fields]) AND (‘standards’[Subheading] OR ‘standards’[All Fields] OR ‘criteria’[All Fields]))
No limits were placed on the search.
Studies conducted on paediatric inpatient populations, aged 0–16 years, in developed countries were included.
One systematic review, 12 papers validating PEWS in paediatric inpatients were found. Five of these papers were included in the systematic review. Seven papers postdate the systematic review.
See table 1.
Paediatric early warning trigger or scoring systems need to alert health professionals about an at-risk child early enough to allow adequate time for treatments and interventions to improve outcome.
There is a large amount of heterogeneity in the paediatric early warning systems investigated in the literature making it difficult to determine the best tool. Each study tested a different paediatric early warning system3–5 ,11–13 or a modified version of a previously validated tool.6 ,8 ,14 ,16
A receiver operating characteristic (ROC) curve is a graphical plot which illustrates the performance of a tool at various thresholds. The area under the ROC curve is used as a global measure of a tool's performance—in this case, giving the probability that the tool correctly identifies children at risk of serious or life-threatening deterioration. An area under the curve (AUC) of greater than 0.8 gives a good overall predictive value and was reached by many PEWS.3 ,5 ,6 ,13 ,14 Only one system3 showed consistently good predictive value when directly compared with other paediatric early warning systems.15
An ideal paediatric early warning tool should trigger escalation of care for at-risk patients (sensitivity) without inappropriately triggering those at low risk (specificity). No single system has a high sensitivity and a high specificity. Instead, a trade-off between sensitivity and specificity is seen. In clinical practice, sensitivity is most important. Failure to identify that a child is at-risk before cardiorespiratory arrest or death occurs is unacceptable. At the best given trigger or cut-off score for each paediatric early warning system, these studies reported 70%–90% sensitivity.5 ,6 ,8 ,9 ,13 ,14 All the tools could miss at-risk children. With higher sensitivity, specificity would lower considerably. This would result in larger numbers of patients triggering the tool inappropriately (false positives), wasting valuable time and resources. There is a trade-off between clinical effectiveness and efficiency.
Current practice in the UK is diverse.17 There are many different paediatric early warning systems in use but the majority are not based on the published and validated data described. Adult UK practice has moved to using one system18 and projects are ongoing to consider one national paediatric PEWS solution.19 ,20
The evidence described does not show that one system excels in predicting serious clinical deterioration. No paediatric early warning system has yet been validated in a large multicentre randomised control study. Patient enrolment to the first, international cluster-randomised trial for the Bedside PEWS11 ,13 was due to be completed in July 2015.21 Therefore, to date, there is no evidence to recommend the use of any one specific published paediatric early warning system in paediatric inpatients and the results of this large randomised international study are eagerly awaited.
The evidence in this review is limited to describing the validity of the early warning tools in inpatient populations only. It cannot be generalised to other settings such as the emergency department as patients in these setting may have different characteristics and pretest probabilities of deterioration from critical illness to the cohorts in the inpatient validation studies presented here. Furthermore, a paediatric early warning tool should form part of pathway or organised system of response to a clinical deterioration. The implementation of a team skilled in the resuscitation and stabilisation of a critically ill child , which is activated rapidly by a paediatric early warning trigger or scoring system, has been shown to reduce adverse events.10 ,22 Having a validated paediatric early warning tool is important so that these teams are activated appropriately. Further appraisal of the literature is needed to determine whether outcomes for critically ill children can be improved by formalising how the paediatric early warning systems are used rather than which trigger or scoring tool is used.
Clinical bottom line
Although some studies have good methodology and show ability to predict deterioration, there is no evidence to support one inpatient paediatric early warning trigger or scoring system over another (grade C).
Paediatric early warning trigger or scoring systems can help healthcare professionals correctly identify deteriorating critically ill children early enough in their physiological decompensation (grade B).
The subsequent activation of an organised system of response, focused on resuscitation and stabilisation, enables specialist resources to be appropriately directed in the most timely manner to children admitted to hospital most at risk of CPA and death (grade C).
Contributors LS conceived the idea for this best evidence topic and performed the literature search. LS drafted the article and AR revised it critically. All authors interpreted the data and approved the final manuscript. AR is the guarantor.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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