Investigation of Lung Ventilation Inhomogeneity in Pediatric Asthma

NCT ID: NCT01095354

Last Updated: 2018-06-29

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 49 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2009-11-30
• Study Completion Date: 2018-05-23

Brief Summary

The primary objective of this study is to determine if well-controlled asthmatic patients followed in subspecialty asthma clinics between the ages of 3 - 18 years can be distinguished from healthy controls using lung clearance index, a parameter from the multiple breath washout test. Also, to correlate lung clearance index with asthma sputum cell counts.

Detailed Description

Clinical studies are underway which are examining the utility of the LCI in obstructive respiratory disease (cystic fibrosis and asthma). However, the majority of studies have examined asthmatics with ongoing evidence of reversible disease on spirometry. There is a very limited body of research comparing LCI values in well-controlled asthmatics to healthy controls. Furthermore, the type of inflammation occurring in asthma may have a different site of action, we will prospectively study whether there is a difference in LCI between eosinophilic and neutrophilic inflammation to give us an indication of whether the site of non-eosinophilic inflammation is primarily in the small airways as well.

Conditions

Asthma

Study Design

• Observational Model Type: COHORT
• Study Time Perspective: PROSPECTIVE

Study Groups

Asthma Patients

Spirometry. Bronchodilator with Salbutamol. Induced sputum in \> 10 years of age using Sodium Chloride Inhalation. Multiple Breath Washout (MBW).

Sodium Chloride Inhalation

Intervention Type: DRUG

Spirometry: all subjects Plethysmography and exhaled nitric oxide: >6 years Multiple Breath Washout: Tidal breathing using a facemask <9 years or mouthpiece >9 years. Wash-in phase: gas mixture containing 4% SF6, 4% He, 21% oxygen and balance nitrogen inhaled until steady state. Bias flow stopped during expiration by removal of T-piece. Wash-out phase: patient inspires room air and exhales tracer gas until SF6 reaches <0.1%.

Bronchodilator response: Bronchodilator (Salbutamol 400 mcg) to asthma subjects, spirometry and MBW repeated after 15 minutes.

Induced sputum in asthma subjects >10 yrs. Post-bronchodilator spirometry, subject inhales concentrations of 3, 4 and 5% hypertonic saline for 7 minutes for 3 cycles until expectorating sputum.

Interventions

Sodium Chloride Inhalation

Spirometry: all subjects Plethysmography and exhaled nitric oxide: >6 years Multiple Breath Washout: Tidal breathing using a facemask <9 years or mouthpiece >9 years. Wash-in phase: gas mixture containing 4% SF6, 4% He, 21% oxygen and balance nitrogen inhaled until steady state. Bias flow stopped during expiration by removal of T-piece. Wash-out phase: patient inspires room air and exhales tracer gas until SF6 reaches <0.1%.

Bronchodilator response: Bronchodilator (Salbutamol 400 mcg) to asthma subjects, spirometry and MBW repeated after 15 minutes.

Induced sputum in asthma subjects >10 yrs. Post-bronchodilator spirometry, subject inhales concentrations of 3, 4 and 5% hypertonic saline for 7 minutes for 3 cycles until expectorating sputum.

Intervention Type: DRUG

Other Intervention Names

Salt, NaCl

Eligibility Criteria

Inclusion Criteria

• Asthma Subjects:

• 3 - 18 years of age at enrolment
• Clinically stable at enrolment
• Physician diagnosis of asthma and attending follow-up in the Asthma Clinic

Exclusion Criteria

• Asthma Subjects:

• Born premature (before 37 weeks gestational age)
• Low birth weight (less than 2.5 kilograms)
• History of congenital heart disease, neuromuscular disorder or bone disease
• History of any chronic lung disease other than asthma
• Respiratory infection in last three weeks
• Change in medication in last three weeks (including oral steroids)
• Current or previous history of smoking

• Minimum Eligible Age: 3 Years
• Maximum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

The Hospital for Sick Children

OTHER

Sponsor Role: lead

Responsible Party

Padmaja Subbarao

Staff Respirologist

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Padmaja Subbarao, MD

Role: PRINCIPAL_INVESTIGATOR

The Hospital for Sick Children

Locations

The Hospital for Sick Children

Toronto, Ontario, Canada

Countries

Canada

Other Identifiers

1000013927

Identifier Type: -

Identifier Source: org_study_id