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

Study Overview
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Brief Summary
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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.

Detailed Description
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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.

Official Title
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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.

Conditions
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Asthma, Status Asthmaticus

Intervention / Treatment
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* Device: Bilevel Positive Airway Pressure (BiPAP) (Trilogy BiPAP, Philips Respironics)
* Other: Standard care


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 2 Years
Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: BiPAP plus standard care<br>Bilevel Positive Airway Pressure (BiPAP) plus standard care according to the hospital's severe asthma protocol | Device: Bilevel Positive Airway Pressure (BiPAP) (Trilogy BiPAP, Philips Respironics)<br>* Children in the intervention group will receive BiPAP (Trilogy, Philips Respironics; spontaneous trigger mode) via a nasal or full face mask. End expiratory positive airway pressure (EPAP) will be set at 5cm H20. Inspiratory positive airway pressure (IPAP) will be titrated to achieve a tidal volume of 6 - 9 ml/kg. These settings will remain unchanged throughout the study period.<br>* Other names: Trilogy BiPAP, Philips Respironics;Other: Standard care<br>* Standard care according to the hospital severe asthma protocol<br>|
| Active Comparator: Standard care alone<br>Standard care according to the hospital's severe asthma protocol | Other: Standard care<br>* Standard care according to the hospital severe asthma protocol<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pediatric Respiratory Assessment Measure (PRAM) clinical severity score of ≤ 3 (mild) | PRAM score includes assessment of oxygen saturations, suprasternal retractions, scalene muscle contraction, air entry and wheezing. | Assessed at initiation, and 3-hourly thereafter until hospital discharge (an estimated average duration of 4 days) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intubation and complication rates | Number of children in each arm requiring intubation and mechanical ventilation, and experiencing significant treatment-related side effects | Patients will be followed for the duration of their hospital stay (an estimated average of 4 days) with data collection relative to this outcome on a daily basis | 
| Hospital re-admission | Number of children in each arm failing initial hospital discharge and requiring re-admission within 48 hours | Within 48 hours of initial hospital discharge | 
| Inhaled bronchodilator utilization | Comparison of the median daily dose of inhaled salbutamol received by children in each arm, | Patients will be followed for the duration of their hospital stay (an estimated average of 4 days) with data collection relative to this outcome on a daily basis | 
| Intravenous bronchodilator utilization | Comparison of the total number of hours of intravenous bronchodilator infusions received by children in each arm | Patients will be followed for the duration of their hospital stay (an estimated average of 4 days) with data collection relative to this outcome on a daily basis | 
| Length of hospital stay | Duration of time from hospital admission to the patient meeting hospital discharge criteria | Length of stay will be calculated at the time of each child's hospital discharge (estimated 4 days after hospital admission and recruitment to study) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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BiPAP