Bronchiolitis is a leading cause of pediatric hospital admissions. Despite its limited clinical benefits, the use of HFNC in children with bronchiolitis is increasing.

Previous studies using quality improvement (QI) methodologies have successfully reduced HFNC usage through weaning protocols and trials of standard oxygen therapy.

This study involves implementing an HFNC initiation and weaning protocol at Aydın Maternity and Children's Hospital, involving infants aged 1-24 months admitted with bronchiolitis.

Bronchiolitis is a leading cause of pediatric hospital admissions. While high-flow nasal cannula (HFNC) is effective as a rescue therapy for patients with severe respiratory distress when standard oxygen therapy fails, studies suggest that early use of HFNC in moderate cases does not significantly improve outcomes such as hospital stay duration or intubation rates. Despite its limited clinical benefits, the use of HFNC in children with bronchiolitis is increasing, raising concerns about unnecessary treatment and extended hospital stays due to a lack of standardized weaning protocols.

Evidence suggests that HFNC should be used effectively as a rescue treatment after standard oxygen therapy fails, serving as an intermediate step before invasive support. However, the high costs and self-limiting nature of bronchiolitis necessitate reducing the overuse of HFNC in hospitalized children. Previous studies using quality improvement (QI) methodologies have successfully reduced HFNC usage through weaning protocols and trials of standard oxygen therapy.

This study involves implementing an HFNC initiation and weaning protocol at Aydın Maternity and Children's Hospital, involving infants aged 1-24 months admitted with bronchiolitis. A multidisciplinary team will evaluate patients using the Respiratory Assessment Scale (RAS), with mild, moderate, and severe classifications. The study compares HFNC duration, hospital stay, oxygen support duration, and associated costs before and after the protocol implementation.

Exclusion Criteria:

Premature infants born at less than 32 weeks Patients with cardiopulmonary, genetic, congenital, or neuromuscular abnormalities were excluded.

A prospective, randomized controlled trial will be conducted to evaluate the effectiveness of a newly developed HFNC (High-Flow Nasal Cannula) weaning protocol in infants aged 1-24 months with bronchiolitis, compared to the standard weaning protocol.

The new HFNC weaning protocol was developed using Quality Improvement (QI) methodology, involving input from pediatricians, nurses, and hospital staff through training sessions. The training lasted one month before the implementation, focusing on classifying patients using the Respiratory Assessment Scale (RAS), which includes respiratory rate, the workload of breathing, and consciousness level. A multidisciplinary team will apply the protocol.

Protocol for Bronchiolitis in Children Under 2 Years:

Aspiration, postural drainage, hydration, antipyretics if necessary, nasal cannula for SpO₂ drop (3-4 L/min)

Despite nasal cannula >3 LPM (FiO₂: 32), hypoxemia (≤92% FiO₂) or moderate-to-severe RAS:

Yes: Start HFNC (High-Flow Nasal Cannula) therapy. No: Continue with HFNC or nasal cannula/mask.

HFNC Therapy Initiation:

Initial FiO₂: 50%, Flow rate: 1-2 L/kg Target SpO₂ between 92-96% by titrating FiO₂. Calculate the baseline ROX index.

Reassess in 30-60 minutes:

Is there clinical deterioration? (Moderate-to-severe RAS)

If clinical deterioration is present:

FiO₂ ≥ 50% SpO₂ < 90% pCO₂ ≥ 60 Positive pressure ventilation should be considered if there is apnea or bradycardia.

If there is no clinical deterioration:

After 4 hours of stable condition, reassess. Is there improvement in RAS and ROX index, and is the patient clinically stable?

Yes:

If FiO₂ < 30%, start weaning the flow rate and FiO₂ simultaneously. Reduce the flow rate by 2 L/min every 2-4 hours, and evaluate the RAS-ROX trend every 2-4 hours.

If there is respiratory deterioration:

Continue or increase HFNC flow rate and FiO₂ as needed.

If there is no respiratory deterioration:

Weaning continues. Discontinue HFNC when the flow rate reaches 4 L/min and FiO₂ < 30%.

Is there respiratory deterioration?

Yes:

Return to the previous flow rate, and reassess within 30 minutes.

Randomization and Groups:

Participants will be randomly assigned to one of two groups:

Control Group: Will follow the existing HFNC weaning protocol. Intervention Group: The intervention group will follow the newly developed multidisciplinary HFNC weaning protocol.

Outcomes:

The 2 groups will be compared regarding HFNC duration, hospital stay, oxygen support duration, intensive care readmission, noninvasive ventilation (NIV) needs, intubation rates, and costs.

Inclusion Criteria:

• Patients older than 1 month and younger than 24 months of age; hospitalized at the PICU with the intention of treatment with HFNC at least for the upcoming 4 hours
• Patients with moderate and severe RAS(Respiratory Assessment Scale) requiring HFNC
• Written informed consent signed and dated by the patient or one relative in case that the patient is unable to consent, after full explanation of the study by the investigator and prior to study participation

Exclusion Criteria:

• İnfants born before 32 weeks of gestation or those with cardiopulmonary, genetic, congenital, or neuromuscular abnormalities.
• Patient with an indication for immediate noninvasive ventilation (NIV)
• Patients deemed at high risk for the need for non-invasive mechanical ventilation within the next 4 hours
• Hemodynamic instability