Investigation of Lung Ventilation Inhomogeneity in Pediatric Asthma

Investigation of Lung Ventilation Inhomogeneity in Pediatric Asthma: Multiple Breath Washout and Asthma

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.

Study Overview

• Status: Completed
• Conditions: Asthma
• Intervention / Treatment: Drug: Sodium Chloride Inhalation

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.

• Study Type: Observational
• Enrollment (Actual): 49

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5G 1X8
      • The Hospital for Sick Children

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 5 months to 14 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Asthma patients will be recruited from the Respiratory Medicine clinic at the Hospital for Sick Children. A member of the medical team in the Asthma Clinic, known to the patient, will introduce the study, and obtain permission for the patient/caregiver to meet with study personnel. Subjects will then be approached by the Principal investigator or her delegate. They will be informed that enrolment is voluntary and that they can withdraw from the study at any time.

Description

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

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

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

Drug: 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.; Other Names: Salt, NaCl

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lung Clearance Index (LCI)	Lung clearance index will be compared between healthy and asthmatic patients after they have performed Pulmonary Function Testing and Multiple Breath Washout	Day 1

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation of sputum cell counts with LCI	Sputum induction for specimen collection	Day 1
Effect of bronchodilator on baseline and post-spirometry LCI		Day 1

Collaborators and Investigators

• Sponsor: The Hospital for Sick Children
• Investigators: Principal Investigator: Padmaja Subbarao, MD, The Hospital for Sick Children

Publications and helpful links

Helpful Links

• Published Article

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2009
• Primary Completion (Actual): May 1, 2015
• Study Completion (Actual): May 23, 2018

Study Registration Dates

• First Submitted: March 23, 2010
• First Submitted That Met QC Criteria: March 29, 2010
• First Posted (Estimate): March 30, 2010

Study Record Updates

• Last Update Posted (Actual): June 29, 2018
• Last Update Submitted That Met QC Criteria: June 27, 2018
• Last Verified: June 1, 2018

More Information

Terms related to this study

• Keywords: pediatric; lung ventilation inhomogeneity
• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Immune System Diseases; Lung Diseases; Hypersensitivity, Immediate; Bronchial Diseases; Lung Diseases, Obstructive; Respiratory Hypersensitivity; Hypersensitivity; Asthma
• Other Study ID Numbers: 1000013927

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Yes
• IPD Plan Description: scientific journal articles