Commentary on the First-Line Support for Assistance in Breathing in Children Trials on Noninvasive Respiratory Support: Taking a Closer Look.

Noninvasive respiratory support modalities such as high-flow nasal cannula (HFNC) therapy and continuous positive airway pressure (CPAP) are used frequently in pediatric critical care to support acutely ill children with respiratory failure (step-up management) and children following extubation (step-down management). Although there are several observational studies and database analyses comparing the efficacy of HFNC and CPAP, and a few small randomized clinical trials (RCTs), until recently, there were no large RCTs comparing the two modalities in a mixed group of critically ill children. In the first half of 2022, results from the First-Line Support for Assistance in Breathing in Children (FIRST-ABC) trials were published; these comprised a master protocol of two trials: one in acutely ill children (step-up RCT) and one in extubated children (step-down RCT). Each of these pragmatic trials randomized 600 children to either HFNC or CPAP when the treating clinician decided that noninvasive respiratory support beyond standard oxygen therapy was required. The primary outcome was time to liberation from all forms of respiratory support (invasive and noninvasive), excluding supplemental oxygen. The FIRST-ABC trials represent a significant advance in the field of noninvasive respiratory support, which has traditionally been evidence-poor and associated with considerable variability in clinical practice. In this article, we provide an overview of how the FIRST-ABC trials were conceived and conducted, our view on the results, and how the trial findings have changed our clinical practice.