None listed
Conditions
Brief summary
This is a parallel group, prospective randomised trial comparing two methods of monitoring asthma control. Participants will be recruited from the Pulmonary Function Laboratory who have been referred for testing using inhaled mannitol to assess BHR in persons who are suspected of having asthma. Following the identification of a positive test, the provision of written consent and once there is confirmation the clinician has prescribed ICS, the subject will be contacted by phone and asked to return to the Laboratory at 6, 12 and 18 weeks to have either a mannitol challenge with spirometry performed or spirometry performed alone. The subject will be provided with feedback at each visit as to the benefit of ICS on the test outcomes and encouraged to seek the goal of achieving a reduction in their airway response to mannitol or improvement in lung function into the normal range. The referring clinician will also be provided with the results at each visit. Subjects will also perform an Asthma Control Questionnaire (ACQ) and Asthma Quality of Life Questionnaire (AQLQ) at each visit and both patient and clinician will be informed of these improvements. Prior to both spirometry and a mannitol challenge, participants will have two rapid non-invasive tests performed that measure the size of the small airways as well as the degree of inflammation by measuring a gas when expired known as nitric oxide.
Interventions
In patients with asthma commencing inhaled corticosteroid (ICS) therapy, we will evaluate if monitoring by inhaled mannitol bronchial provocation challenge testing will provide a greater and more sustained control of asthma over 18 weeks compared with monitoring by spirometry alone.
We will use the inhaled mannitol bronchial provocation test to monitor bronchial hyperresponsiveness (BHR) in the intervention group. Results of the test would be reviewed by the patients and their treating physicia
In patients with asthma commencing inhaled corticosteroid (ICS) therapy, we will evaluate if monitoring by inhaled mannitol bronchial provocation challenge testing will provide a greater and more sustained control of asthma over 18 weeks compared with monitoring by spirometry alone. We will use the inhaled mannitol bronchial provocation test to monitor bronchial hyperresponsiveness (BHR) in the intervention group. Results of the test would be reviewed by the patients and their treating physicians to allow assessment of the current control of their asthma. The intervention group will have the mannitol challenge at baseline, 6, 12 and 18 weeks. The control group will be seen at the same time points, but will receive the results of spirometry only. The challenge involves inhaling a series of doses of mannitol powder using a small inhaler device, until a total of 635mg has been inhaled or the participant has had a fall in FEV1 of 15% or more from the baseline spirometry for the visit. A lower dose of mannitol required to induce a fall in spirometry indicates more severe bronchial hyperresponsiveness. The participants will be followed for 18 weeks from baseline.
Sponsors
Sydney Local Health District - Royal Prince Alfred Hospital
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
-Males and females age 18-75 years -Pre-bronchodilator FEV1 greater than or equal to 70% of predicted and greater than 1L -A positive response to mannitol challenge (PD15 of less than 635mg) -Prescribed ICS treatment after initial challenge -Non-smokers; ex-smokers with less than 10 pack years and no cigarettes within the last 12 months ACQ score greater than 0.75
Exclusion criteria
-Evidence of significant cardiovascular, haematological, hepatic, renal, neurological or psychiatric disease or any other major immunological or pulmonary disease other than asthma. -Upper or lower respiratory tract infection within 2 weeks of the baseline visit, which may or may not have required a course of oral antibiotics -Administration of an investigational drug in the preceding 4 months -Subjects positive to mannitol that are being assessed as defence or police recruits
Outcome results
None listed