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

Not Applicable

Withdrawn

Interventions: Other: Standard care
Device: Bilevel Positive Airway Pressure (BiPAP) (Trilogy BiPAP, Philips Respironics)

Brief Summary: 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: 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.

Recruitment & Eligibility

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

Arm && Interventions

Group	Intervention	Description
Standard care alone	Standard care	Standard care according to the hospital's severe asthma protocol
BiPAP plus standard care	Bilevel Positive Airway Pressure (BiPAP) (Trilogy BiPAP, Philips Respironics)	Bilevel Positive Airway Pressure (BiPAP) plus standard care according to the hospital's severe asthma protocol
BiPAP plus standard care	Standard care	Bilevel Positive Airway Pressure (BiPAP) plus standard care according to the hospital's severe asthma protocol

Primary Outcome Measures

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

Secondary Outcome Measures

Name	Time	Method
Inhaled bronchodilator utilization	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	Comparison of the median daily dose of inhaled salbutamol received by children in each arm,
Hospital re-admission	Within 48 hours of initial hospital discharge	Number of children in each arm failing initial hospital discharge and requiring re-admission within 48 hours
Intubation and complication rates	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	Number of children in each arm requiring intubation and mechanical ventilation, and experiencing significant treatment-related side effects
Intravenous bronchodilator utilization	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	Comparison of the total number of hours of intravenous bronchodilator infusions received by children in each arm
Length of hospital stay	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)	Duration of time from hospital admission to the patient meeting hospital discharge criteria

Locations (1): Children's and Women's Hospital
🇨🇦
Vancouver, British Columbia, Canada