Bilevel Positive Airway Pressure (BiPAP) for the Treatment of Moderate to Severe Acute Asthma Exacerbations

A Prospective Open Randomized Clinical Trial Comparing Bilevel Positive Airway Pressure (BiPAP) Therapy Against Standard Therapy for Children Hospitalized With an Acute Exacerbation of Asthma Unresponsive to Inhaled Bronchodilators.

Bilevel Positive Airway Pressure (BiPAP) is increasingly being reported as an effective and safe method of respiratory support for children with severe asthma exacerbations unresponsive to standard therapies and with impending respiratory failure. Much of the evidence base supporting its use comes from retrospective observational studies, and there is currently a lack of data from randomized controlled trials to inform this practice.

The investigators hypothesize that the use of BiPAP in children with moderate to severe asthma exacerbations could reduce the length of hospital stay, need for invasive ventilation, and use of intravenous bronchodilators. The investigators aim to test this hypothesis by randomizing children attending the Emergency Department with a moderate to severe clinical severity score refractory to inhaled bronchodilators to receive either BiPAP in addition to standard asthma care, or standard care alone.

Children aged 2 - 18 years presenting to the Emergency Department (ED) with a moderate or severe asthma exacerbation (Pediatric Respiratory Assessment Measure (PRAM) of > 3) who fail to improve clinically with standard ED management with inhaled salbutamol and ipratropium will be randomized to receive either standard asthma management according to our local severe asthma guideline or management with BiPAP in addition to standard care. Both groups will receive a comparable dose of systemic steroid and hourly salbutamol inhalers with subsequent weaning according to PRAM score. Patients randomized to receive BiPAP will be admitted to the Pediatric Intensive Care Unit (PICU) and those randomized to the control group will be admitted to the medical ward. Both groups will be monitored with 3-hourly PRAM scoring through the duration of their admission.

Inclusion Criteria:

• 2-18 years old
• Admitted to BC Children's Hospital with a clinical diagnosis of an acute asthma exacerbation
• PRAM score of >3 following initial treatment with three rounds of inhaled salbutamol and ipratropium bromide, and one dose of systemic steroid
• Parents willing and able to sign consent
• Children over the age of 6 willing to provide assent

Exclusion Criteria:

• Clinical suspicion of co-existing bacterial pneumonia: focal crackles or bronchial breathing, and/or major chest x-ray findings
• Impending respiratory failure at presentation requiring direct PICU admission
• Receiving maintenance dose of oral steroid at time of hospital admission
• Any contraindication to BiPAP use including altered mental status, recent bowel surgery, intractable vomiting, or inability to protect airway
• Current tracheostomy, home ventilation (IPPV or NIPPV) or home oxygen requirement
• History of congenital heart disease or chronic respiratory disease (including bronchopulmonary dysplasia, cystic fibrosis, pulmonary hypertension)
• Craniofacial abnormality precluding the use of a tight fitting facial mask