FIRST-ABC Pilot: FIRST-line support for Assistance in Breathing in Children Pilot Study


Breathing support is the most common treatment given to sick children in a paediatric intensive care unit (PICU). There are two kinds of breathing support: invasive (via a tube into the wind pipe); and non-invasive (via a mask or hood over the face). Both methods are routinely used. However, there are concerns of increased risk of infection and lung damage associated with invasive breathing support and this has prompted greater use of non-invasive breathing support.

The traditional method of delivering non-invasive breathing support is through continuous positive airway pressure (CPAP). It is effective but often poorly tolerated by children. A newer method, high flow nasal cannula (HFNC), has rapidly become popular due to its ease of use and increased tolerance. However, this method is much more expensive. Therefore, a clinical trial is needed to compare these two different methods.


This pilot study tested whether it was possible to conduct the large-scale trial. We included children requiring non-invasive breathing support admitted to PICUs in three NHS hospitals. Patients were randomised into two groups: 1. patients requiring non-invasive breathing support as a ‘step-up’ treatment to prevent the need for invasive ventilation which requires intubation – a procedure where a tube to be placed into the child’s airway; and 2. to avoid the need for re-intubation after being ‘stepped-down’ from receiving invasive ventilation. Patients included in these two groups were randomly allocated to receive either CPAP and HFNC as their mode of breathing support.


Overall, 121 children (48% of eligible patients) were enrolled in the trial over a 10-month period. Consent rates were higher from parents/guardians in the approached in the step-up group (88%) compared with parents/guardians approached in the step-down group (71%). More patients switched treatment from HFNC to CPAP (step-up: 44%; step-down: 21%) than from CPAP to HFNC (step-up: 23%; step-down: 12%). Intubation within 72 hours from inclusion into the study occurred in 25% of patients randomised to HFNC and 19% of patients randomised to CPAP. HFNC patients experienced fewer ventilator-free days at day 28 (step-up: 19.6 vs. 23.5 days; step-down: 21.8 vs. 22.2).


Our pilot trial confirms that, following minor changes to consent procedures and treatment algorithms, it is feasible to conduct a large national randomised controlled trial of non-invasive respiratory support in the paediatric critical care setting in both step-up and step-down patients.

Who led this study?

Dr Padmanabhan Ramnarayan, Great Ormond Street Hospital for Children NHS Foundation Trust, London

This study was funded by the Great Ormond Street Hospital Children’s Charity (Project: 14HC30)


Ramnarayan P, Lister P, Dominguez T, Habibi P, Edmonds N, Canter RR, Wulff J, Harrison DA, Mouncey PM, Peters MJ. FIRST-line support for Assistance in Breathing in Children (FIRST-ABC): a multicentre pilot randomised controlled trial of high-flow nasal cannula therapy versus continuous positive airway pressure in paediatric critical care. Crit Care 2018; 22(1):144.

Ramnarayan P, Lister P, Dominguez T, Habibi P, Edmonds N, Canter R, Mouncey PR, Peters MJ. FIRST-line support for Assistance in Breathing in Children (FIRST-ABC): protocol for a multicentre randomised feasibility trial of non-invasive respiratory support in critically ill children. BMJ Open 2017; 7(6).