• Intensive Care Units, Paediatric
• Epidemiology

With the centralisation of paediatric intensive care services in England in the late 1990s, the development of transport services to transfer critically ill children from their local hospital to a tertiary centre became essential. To begin with, many of these services were provided by teams within those same regional paediatric intensive care units (PICUs), but over time specialist paediatric critical care transport services developed. The study by Ramnarayan et al1 describes how the development of a national database collecting data over a 10-year period across the UK and Ireland has been able to track more recent changes in provision, such that all areas are now covered by specialist paediatric critical care transport teams, along with a doubling in the number of transports led by an advanced nurse practitioner. At the same time, as well as having separately staffed transport teams, the auditing of performance has led to improvements in the speed at which teams mobilise for a transfer, although the challenges of geography and the minimal use of air transport may have limited any improvement in teams reaching the bedside of a critically ill child within 3 hours. Modelling has suggested that it may not be possible to optimise the arrangements that have developed regionally,2 such that advances in this latter metric may prove challenging.

The national database has been able to demonstrate trends in clinical practice, such as the reduced use of advanced vascular access with no significant change in the number of transfers requiring vasoactive infusions. The increased use of peripheral infusions perhaps reflects greater experience of specialist transport teams regarding which interventions are truly necessary to undertake a safe transfer. The authors also note that this practice was accelerated during the COVID-19 pandemic with the emergence of Paediatric Inflammatory Multisystem Syndrome temporally associated with COVID-19 (PIMS-TS) in older children who did not necessarily require any ventilatory support.

While there has been an increase in the overall number of transports to a PICU in the UK and Ireland over the 10-year period of the study, these greater numbers include more older children as opposed to infants. Earlier studies have suggested that children transferred to the PICU by a specialist team are at lower risk of mortality, and the acuity of illness appears to have changed further with a small but consistent reduction in the median risk of mortality for those transported. Some of that may be related to a doubling in the number of elective transfers per year, although this still accounts for less than 10% of the total. By contrast, of all of the transports initiated, death occurred in approximately 1% prior to transport completion, suggesting that some of the mortality risk for children needing PICU is unaccounted for, although death during the transfer itself is thankfully a rare occurrence.

The number of transports undertaken with invasive ventilation has not changed, while the use of non-invasive ventilation during transport, while still relatively limited, has nearly doubled, which may reflect changes in the confidence of specialist transport teams in providing this support, advances in transport ventilator technology and shifts in the patient cohort, consistent with an increase in the number of children with chronic complex conditions admitted to PICU. These children are at greater risk of PICU admission with acute respiratory illnesses compared with the wider paediatric population.3 This may also in part explain the finding that there were over 43 000 transports in 36 000 children, suggesting some children needing multiple transfers during this time.

So will the number of paediatric critical care transfers undertaken by specialist teams in the UK and continue to rise in the next 10 years? There are a number of reasons to think that this may not be the case.

Firstly, moves have already been made to avoid transfer for children intubated for status epilepticus. Despite long-standing concerns about the de-skilling of clinicians in local hospitals with the centralisation of services, some transport teams have been able to embed the practice of local extubation in most of these cases.4 Spreading that practice more widely would clearly be beneficial both from a family and a service perspective. Secondly, the introduction of wider immunisation protocols for respiratory syncitial virus (RSV) may significantly reduce the number of babies needing invasive ventilation during the winter period.

Although the population of children with risk factors for PICU admission is unlikely to decrease, with increasing numbers of preterm neonatal survivors who are at greater risk of requiring admission to PICU in the first 2 years of life, there are changes happening in terms of wider service provision. The NHS England Paediatric Critical Care and Surgery in Children Review published in 2019 reported capacity concerns for PICU (Level 3) beds. One of the recommendations of this review was the development of Level 2 beds in larger and busier district general hospitals which could provide non-invasive ventilatory support. This might allow the critical care of some of those at-risk infants to be managed entirely outside of a PICU. It also has the benefit of providing care closer to home, especially for children with chronic complex conditions requiring non-invasive ventilatory support, and for their families who will likely have developed long-term relationships with their local paediatric teams. Interestingly having been a driver for centralisation in England nearly 30 years ago, a similar provision to this is now also being proposed in Australia as a way forward, given comparable changes in their PICU population demographics. For England, the scope of the Paediatric Intensive Care Audit Network database has been expanded to capture all Level 2 activity, both in tertiary centres and in those designated local hospitals, and in time this should provide evidence for how well this development is performing.

So if the quantity of paediatric critical care transports in the UK and Ireland may not increase in the coming years. what advances can be made in the quality of practice?

As the authors note, more can be done in terms of consistent incident reporting to ensure the quality of the services provided. Another quality marker is the ability of parents to accompany their child in the ambulance. The percentage of transports where this occurred was rising steadily until the COVID-19 pandemic, when infection control concerns led to a dramatic increase in permission for this being withheld, but as of 2022, a return to previous levels was observed and this practice should continue to be encouraged. Travelling in the ambulance has been noted to increase parental exposure to the specialist transport team, which in itself may reduce parental stress.5

Greater use of telemedicine for transport referrals may support local teams with the management of critically ill children prior to the arrival of the specialist transport team, especially given the number of children identified who died after a call was initiated but before a transfer to PICU could be completed. It may also support local teams that are still required to undertake time-critical transfers of children needing specialist treatment.

Continued routine audit data collection of paediatric transport services on a national basis should be able to identify and drive changes in future practice and as Ramnarayan et al suggest, it could help support the development of similar paediatric transport databases for healthcare systems elsewhere in the world.