Please select the eligibility criteria that correspond to the clinical trial below.
Title: FIRST-ABC Feasibility Study: Feasibility Study for a Randomised Trial of High Flow Nasal Cannula (HFNC) Versus Continuous Positive Airway Pressure (CPAP) for Non-invasive Respiratory Support in Critically Ill Children
Brief Summary: A feasibility study to inform the design and conduct of a randomised controlled trial of high flow nasal cannula (HFNC) versus continuous positive airway pressure (CPAP) for non-invasive respiratory support in critically ill children


Options:
A: Inclusion Criteria:

* 1) receiving NCPAP ventilatory support at \> 72 hrs. of age and 2) requiring FiO2 21-50% on NCPAP.

Exclusion Criteria:

* FiO2 \>50%, presence of pneumothorax or pleural effusion, anatomical abnormalities of the airway, lungs, or esophagus, or cyanotic congenital heart defect.
B: Inclusion Criteria:

* Clinical diagnosis of bronchiolitis defined as the first viral episode of respiratory distress before 2 years of aging, presenting with rhinitis, tachypnea, cough, wheezing, prolonged expiratory time, crackles and use of accessory muscles, with or without fever, with or without infiltrate on the chest X ray
* bronchiolitis severity Wang modified score ≥ 10

Exclusion Criteria:

* recurrent wheezing
* heart disease
* chronic lung disease
* neuromuscular disease
* primary diagnosis was not bronchiolitis (pneumonia, pertussis)
* critically ill infants who had an immediate need of intubation
C: Inclusion Criteria:

Eligible patients will fall into one of two groups:

Group A (Step-up)

1. Age \>36 weeks corrected gestational age and \<16 years, AND
2. Deemed to require non-invasive respiratory support by the treating clinician for an acute illness, AND
3. Satisfies one or more of the following criteria:

   * Hypoxia (oxygen saturation \<92% in fraction of inspired oxygen (FiO2) \>0.40, or equivalent). FiO2 of 0.40 roughly equates to standard unhumidified nasal cannula oxygen delivered at 6 L/min or oxygen delivered via facemask without a rebreather bag at 6-10 L/min.
   * Acute respiratory acidosis (pH \<7.3 with a concomitant pCO2 \>6.5 kPa)
   * Moderate respiratory distress (use of accessory muscles, subcostal and intercostal recession, tachypnoea for age, grunting)

Group B (Step-down)

1. Age \>36 weeks corrected for gestation and \<16 years, AND
2. Deemed to require non-invasive respiratory support by the treating clinician after extubation, following a spell of invasive ventilation

   * Either immediately after extubation as a 'planned' procedure, irrespective of clinical condition ('planned') OR
   * Prompted by deterioration in clinical condition within 72 hours after extubation ('rescue'). Clinical parameters to assess the need for NRS in this situation will be similar to point 3 in Group A.

Exclusion Criteria:

1. Deemed by the treating clinician to require immediate intubation/invasive ventilation due to severe hypoxia, acidosis and/or respiratory distress, upper airway obstruction or recurrent apnoeas
2. Tracheostomy in place
3. Pre-existing air-leak syndrome (pneumothorax/pneumomediastinum)
4. Midfacial/craniofacial anomalies (unrepaired cleft palate, choanal atresia) or had recent craniofacial surgery
5. Agreed limitation of intensive care treatment plan in place ('not for intubation')
6. On domiciliary non-invasive ventilation prior to PICU admission
7. Managed on either HFNC and/or CPAP (or other form of non-invasive ventilation such as BiPAP) in the preceding 24 hours
8. Previously recruited to this study during the same PICU admission
9. Cannot be treated with HFNC

   * Unavailability of appropriate sized nasal prongs
   * Unavailability of HFNC device
10. Cannot be treated with CPAP

    * Unavailability of right size of face mask, prong or other patient interface
    * Unavailability of CPAP device
D: Inclusion Criteria:

* Children aged 6 months or less
* Moderate (Respiratory Distress Assessment Instrument score of 4 or greater) viral bronchiolitis (as defined by McConnockie)
* Meeting Admission criteria

Exclusion Criteria:

* History of prematurity
* Chronic lung disease
* Cystic fibrosis
* Congenital heart disease
* Neuromuscular disease
* Airway anomalies
* Immunodeficiency
* Those requiring immediate intubation and ventilation.

Answer: C