Comparison of Nebulizers in ED in Pediatric Asthma Patients

Comparison of a Breath Enhanced High Density Jet Nebulizer With a Standard Jet Nebulizer for the Treatment of Children With a Moderate to Severe Asthma Exacerbation in the Emergency Department

The primary objective will be, in an open-label randomized trial, a comparison of emergency department (ED) length of stay (LOS) between children experiencing acute asthma treated with two different nebulizers. Secondary outcomes will include admission rates, hospital LOS, need for additional therapies, transfers to a higher level of care, side-effects, and unscheduled return visits

To our knowledge, no study has compared a breath-enhanced nebulizer to a standard jet nebulizer for the treatment of acute asthma in children. The goal of this study is to determine whether a rapid albuterol delivery pathway with a breath-enhanced nebulizer can reduce ED LOS, while maintaining admission rates, repeat visits, adjunctive therapies, and side-effects, when compared to a traditional asthma pathway with a standard jet nebulizer. The Salter® Nebutech® HDN® was chosen because its breath-enhanced design and bolus delivery system may deliver greater amounts of albuterol to the small airways, in a shorter period of time, when compared with standard jet nebulizers and other nebulizers in its class. The study site will be a large, urban pediatric emergency department (ED) with approximately 80,000 visits per year. The study protocol will be submitted to the hospital's Institutional Review Board (IRB) for approval. Children will be eligible for enrolment if they are between 3 and 18 years of age and present to the ED with an acute asthma exacerbation of at least moderate severity. The lower age cutoff was chosen because asthma diagnosis and beta agonist response can be unreliable in younger children. The upper age cutoff was chosen to include only pediatric patients, as this is a pediatric asthma study. Children must have a history of physician-diagnosed asthma as reported by the parent or guardian. Children will be enrolled when a research team member is available to obtain informed consent (convenience sample). Children will be excluded from enrollment if the initial pediatric asthma score (PAS) is < 3, immediate resuscitation is required, they have a history of chronic lung disease or congenital heart disease, they have any neuromuscular disease, intrathoracic foreign body is suspected, they are or may be pregnant, they are currently breast feeding, they have received oral or parenteral steroids within the last week (inhaled steroids are allowed), or they have an allergy or other contraindication to one of the study medications. Potential subjects will be identified in triage and screened for enrolment if study personnel are available. If consented, the patient will be randomized to one of the two treatment arms. If there will be greater than a 15 minute delay in treatment due to the consent process, unit dose (2.5 mg) albuterol treatments will be given with a standard nebulizer up to 3 times as needed. That patient may still be enrolled provided he/she still meets inclusion/exclusion criteria.

Patients randomized to the "standard" arm will receive treatments as dictated by our standard ED asthma pathway (Fig. 1). All treatments will be administered with our standard ED nebulizer, the Hudson RCI® Up-Draft® Neb-U-Mist® nebulizer (Teleflex Medical®, Research Triangle Park, NJ), and a simple mask (Hudson RCI®, Teleflex Medical®, Research Triangle Park, NJ).

Patients randomized to the "NebuTech®" arm will receive treatments as dictated by our trial pathway, referred to as the "rapid Albuterol/Proventil delivery pathway" (Fig. 2). All nebulizations in this arm will be administered via the Breath-Enhanced High Density Jet Nebulizer, NebuTech® HighDensityNebulizer®,(Salter Labs®, Arvin, CA). Respiratory Therapists (RT) will attempt to deliver all treatments with a mouthpiece, as that has been shown to be the most efficient and reliable mode of aerosol delivery for most children 31, 32. If the Respiratory Therapist feels that the child will not or cannot effectively use a mouthpiece, a mask will be used.

After the first hour of treatment, patients in the standard arm will receive a repeat assessment, including all of the measurements collected at baseline as well as reported side effects. Those patients who score PAS 0-2 will then be discharged home, after an optional observation period, as per the pathway. Those who score PAS > 2 will receive a second treatment. At the end of the second treatment patients will again be re-assessed, and repeat measurements obtained. At that time, depending on the patient's PAS score, he/she will be dispositioned to home, the floor, the pulmonary high acuity unit (PHAU), or the pediatric intensive care unit (PICU).

All treatments in the NebuTech® arm will be given at a standard dilution of 5 ml (diluted with normal saline to a total volume of 5 ml as per the manufacturer's recommendation). Patients in this arm will receive up to four treatments with parameters measured after each treatment, similar to the control arm. Patients who complete four treatments will then be dispositioned based on PAS score, similar to the control arm. Subjects may have started treatment prior to consent and may receives unit dose (2.5 mg) Albuterol/Proventil treatments will be given with a standard nebulizer up to 3 times as needed and may change over to study randomized device once consented to eith arm.

Subjects may have started treatment prior to consent and may receives unit dose (2.5 mg) Albuterol/Proventil treatments will be given with a standard nebulizer up to 3 times as needed and may change over to study randomized device once consented to eith arm.

The Primary Objective Will be, in an Open-label Randomized Trial, a Comparison of Emergency Department (ED) Length of Stay (LOS) Between Children Experiencing Acute Asthma Treated With Two Different Nebulizers

The primary endpoint will be mean ED LOS difference between the groups. Using historical data as a guide, we calculated a baseline LOS mean for discharged patients of 181 minutes, and standard deviation (SD) of 83 minutes. For this reason, an interim analysis will be conducted in order to assess a pilot sample for the purpose of estimating these values. 25 subjects in each arm (50 subjects total) will be enrolled during the initial phase of the study. This early phase interim analysis is not powered to test for differences between the groups, but establish pilot-phase findings that can be used for more accurate sample size calculation. However, the primary outcome of ED LOS will then be tested to determine the difference between study arms, using the non-parametric Mann-Whitney U test due to the likely skewed-nature of the distribution of ED LOS values for the purpose of establishing an estimate of effect size in the initial enrollment phase.

Baseline characteristics (demographics, history, and clinical characteristics of presentation) of subjects in each treatment arm will be summarized in a table. These descriptive characteristics will be compared between arms using standard t-test or a non-parametric alternative for linear values (eg, age) and chi-squared tests for binomial or categorical values (eg, gender) with p-values reported in the summary table.

Baseline characteristics (demographics, history, and clinical characteristics of presentation) of subjects in each treatment arm will be summarized in a table. These descriptive characteristics will be compared between arms using standard t-test or a non-parametric alternative for linear values (eg, age) and chi-squared tests for binomial or categorical values (eg, gender) with p-values reported in the summary table.

Baseline characteristics (demographics, history, and clinical characteristics of presentation) of subjects in each treatment arm will be summarized in a table. These descriptive characteristics will be compared between arms using standard t-test or a non-parametric alternative for linear values (eg, age) and chi-squared tests for binomial or categorical values (eg, gender) with p-values reported in the summary table.

Baseline characteristics (demographics, history, and clinical characteristics of presentation) of subjects in each treatment arm will be summarized in a table. These descriptive characteristics will be compared between arms using standard t-test or a non-parametric alternative for linear values (eg, age) and chi-squared tests for binomial or categorical values (eg, gender) with p-values reported in the summary table

Baseline characteristics (demographics, history, and clinical characteristics of presentation) of subjects in each treatment arm will be summarized in a table. These descriptive characteristics will be compared between arms using standard t-test or a non-parametric alternative for linear values (eg, age) and chi-squared tests for binomial or categorical values (eg, gender) with p-values reported in the summary table.

Inclusion Criteria: Age ≥ 3 years and < 18 years History of physician-diagnosed asthma Presenting to ED with acute asthma exacerbation according to attending physician Exclusion Criteria: PAS score < 3 Immediate resuscitation required Chronic lung disease (other than asthma) Congenital heart disease 5. Neuromuscular disease 6. Suspected intrathoracic foreign body 7. Is or may be pregnant 8. Currently breast feeding 9. Oral or parenteral steroids within the last 7 days 10. Allergy or other contraindication to any of the study medications