Modelling the allocation of paediatric intensive care retrieval teams in England and Wales

Paediatric Major Trauma: A Retrospective Observational Comparison of Mortality in Prehospital Bypass and Secondary Transfer in the East of England

Background More than half of seriously injured children are not initially treated at a major trauma centre (MTC). Children may be transported by private vehicle to a trauma unit (TU). Children may also be transported by emergency medical services (EMS) to the nearest TU with approximately one in five of these undergoing secondary transfer to an MTC. Most trauma networks permit TU bypass to an MTC. However, the evidence on outcomes between transfer and bypass is limited. This study aimed to evaluate the use of the trauma network by comparing outcomes between paediatric major trauma patients by the method of presentation. Methods In this retrospective observational study, a consecutive sample of paediatric (<16 years old) major trauma patients transported to the regional MTC (Cambridge University Hospitals NHS Foundation Trust (CUH)) between 1st January 2015 and 31st December 2020 was included. Patients were excluded if they arrived at the MTC >24 hours post-injury or were transported to the MTC as the nearest hospital. Patients were divided into four groups: self-presented to MTC, MTC as nearest hospital, bypass and secondary transfer. Results A total of 315 patients (28 'self-presented', 55 'nearest', 58 'bypass' and 174 'secondary transfers') were included. The median age was 9.4 [3.7-13.6] years, and n=209 (66.3%) were male. The median Injury Severity Score (ISS) was 16.0 [9.0-25.0] and n=190 (60.3%) had an ISS >15. There was no difference in 30-day mortality between the 'bypass' and 'secondary transfer' groups. There was a significantly longer hospital and intensive care unit length of stay (LOS) in the bypass group compared to other groups, both p<0.001. The median time to definitive care was five hours greater in the secondary transfer group compared to 'bypass' (bypass 117.6 minutes [100.8-136.6], secondary transfer 418.8 minutes [315.6-529.8]). Conclusion There was no significant difference in 30-day mortality of paediatric major trauma patients who underwent secondary transfer compared to those transported directly from the scene to the MTC, despite significant time delays in reaching definitive care.

Using a genetic algorithm to solve a non-linear location allocation problem for specialised children’s ambulances in England and Wales

Since 1997, special paediatric intensive care retrieval teams (PICRTs) based in 11 locations across England and Wales have been used to transport sick children from district general hospitals to one of 24 paediatric intensive care units. We develop a location allocation optimisation framework to help inform decisions on the optimal number of locations for each PICRT, where those locations should be, which local hospital each location serves and how many teams should station each location. Our framework allows for stochastic journey times, differential weights for each journey leg and incorporates queuing theory by considering the time spent waiting for a PICRT to become available. We examine the average waiting time and the average time to bedside under different number of operational PICRT stations, different number of teams per station and different levels of demand. We show that consolidating the teams into fewer stations for higher availability leads to better performance.

Does time taken by paediatric critical care transport teams to reach the bedside of critically ill children affect survival? A retrospective cohort study from England and Wales

Background

Reaching the bedside of a critically ill child within three hours of agreeing the child requires intensive care is a key target for Paediatric Critical Care Transport teams (PCCTs) to achieve in the United Kingdom. Whilst timely access to specialist care is necessary for these children, it is unknown to what extent time taken for the PCCT to arrive at the bedside affects clinical outcome.

Methods

Data from transports of critically ill children who were admitted to Paediatric Intensive Care Units (PICUs) in England and Wales from 1 January 2014 to 31 December 2016 were extracted from the Paediatric Intensive Care Audit Network (PICANet) and linked with adult critical care data and Office for National Statistics mortality data. Logistic regression models, adjusted for pre-specified confounders, were fitted to investigate the impact of time-to-bedside on mortality within 30 days of admission and other key time points. Negative binomial models were used to investigate the impact of time-to-bedside on PICU length of stay and duration of invasive ventilation.

Results

There were 9116 children transported during the study period, and 645 (7.1%) died within 30 days of PICU admission. There was no evidence that 30-day mortality changed as time-to-bedside increased. A similar relationship was seen for mortality at other pre-selected time points. In children who waited longer for a team to arrive, there was limited evidence of a small increase in PICU length of stay (expected number of days increased from: 7.17 to 7.58).

Conclusion

There is no evidence that reducing the time-to-bedside target for PCCTs will improve the survival of critically ill children. A shorter time to bedside may be associated with a small reduction in PICU length of stay.