title: Critical deterioration in children admitted to hospital, requiring emergency transfer to the Paediatric Intensive Care Unit
Creators: name: Sefton, Geraldine
Publisher: name: University of Liverpool Repository
Year: 2026

description: Abstract. Introduction. Critical deterioration in children admitted to hospital, which results in emergency transfer to the Paediatric Intensive Care Unit (PICU), is associated with increased morbidity and mortality. To date, the interventions aimed at reducing critical deterioration have focused on Paediatric Early Warning Scores (PEWS) and/or Rapid Response Team (RRT) utilisation. This thesis explored the association between antecedent risk factors and Critical Deterioration Events (CDE), and the clinical impact of PEWS utilisation on CDE and outcome. Finally, the proof-of-concept testing for an Electronic Physiological Surveillance System (EPSS) is presented, as an aid to deterioration recognition in children admitted to hospital. Methods. A fourteen-year dataset of PICU admissions, collected prospectively, was used to conduct a post-hoc epidemiological study. Antecedent risk factors associated with CDE were identified by comparing characteristics of the CDE cohort with other PICU admissions. The impact of PEWS, in different formats, on CDE were evaluated by comparing time segments of traditional clinical care (baseline) with the use of a paper-based PEWS trigger tool, a paper-based age-specific aggregate PEWS score and an age-specific aggregate PEWS score within the Electronic Patient Record (EPR). Comparisons were made between these time segments by standardising the data per 1,000 events. Finally, proof-of-concept-testing of an EPSS prototype for use in children was evaluated by comparing the time efficiency and accuracy of vital signs documentation, accuracy of PEWS calculation and user-perceptions of the clinical utility of this technology, compared with paper-based age-specific PEWS charts. Results. Antecedent risk factors associated with CDE were younger age (median 6 vs 10.5 months, p&lt;0.0001), prematurity (less than 32/40, p&lt;0.001), emergency index admission to hospital (p&lt;0.001), respiratory illness and any previous ICU admission (p&lt;0.001). PEWS utilisation did not reduce the prevalence of CDE in a hospital or PICU population, but was associated with a lower Paediatric Index of Mortality (PIM3) at PICU admission, with improvement sustained across the four time segments (median PIM3 of 0.05, 0.045, 0.039 and 0.027, respectively). Late transfer of CDE to PICU was associated with 29% mortality. CDEs post PEWS utilisation had a reduced requirement for invasive ventilation (p&lt;0.002), a shorter duration of ventilation, a shorter length of PICU stay and reduced PICU mortality (p&lt;0.0001). There were associated organisational benefits of reduced PICU bed days used by emergency transfers following CDE (p&lt;0.014). Proof-of-concept testing of an EPSS prototype for use in children showed improved accuracy of vital signs documentation and PEWS calculation, improved time efficiency for documentation and improved clinical utility, compared to paper charts. Conclusion. The results arising from this thesis provide original contributions to knowledge. These incorporate evidence which showed that antecedent risk factors were strongly associated with subsequent CDE. PEWS utilisation was not associated with a reduced prevalence of CDE. However, even when implementation fidelity of PEWS could not be assured, there were associated patient benefits and PICU productivity gains. The proof-of-concept testing of an EPSS for use in children admitted to hospital, suggested that there were time efficiency, documentation accuracy and clinical utility benefits. These results suggest that a more pro-active process to identify evolving signs of deterioration is possible and that these have the potential to improve patient outcome. A large scale follow-on study is required to explore the use of an EPSS in a whole hospital population of children.