The Effect of Deep Inhalation on Mannitol Responsiveness

University of Saskatchewan

Status and phase: Completed; Phase 3

Conditions: Asthma

Treatments: Drug: Mannitol; Procedure: Tidal breathing technique; Drug: Methacholine; Procedure: Deep inhalation technique

Study type: Interventional

Funder types: Other

Identifiers

NCT03505489

MAN-2018

Details and patient eligibility

About

The study will assess how the inhalation technique used (deep inhalations versus tidal breathing) influences the results of a mannitol challenge test and a methacholine challenge test, if at all.

Full description

This study will look at airway responsiveness to inhaled methacholine and mannitol administered with and without deep inhalation. This study will also investigate the role of airway inflammation on these responses, using sputum differential cell counts and fractional exhaled nitric oxide.

This is a single center, open label, randomized study. Individuals with stable asthma will be eligible for enrollment. The study will consist of two parts, screening and testing.

Part 1: Screening

Participants will undergo consent procedures and assessments of fractional exhaled nitric oxide levels, airway responsiveness to methacholine and sputum induction. If participants show airway responsiveness to methacholine (i.e. methacholine PC20 16mg/mL), they will be scheduled to undergo the testing part of the study.

Part 2: Testing

Participants will be randomized to undergo two methacholine or two mannitol challenges. Further randomization will occur with respect to whether the standard challenge method or the modified challenge method is performed first.

Enrollment: 26 patients

Sex: All

Ages: 18 to 75 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• signed informed consent
• men and women between 18 and 75 years of age
• FEV1 at first measurement of greater than or equal to 65% predicted
• methacholine provocative concentration causing a 20% in FEV1 at screening that is less than or equal to 16mg/ml
• generally good health
• stable asthma

Exclusion criteria

• respiratory infection within 4 weeks of screening visit
• worsening of asthma within 4 weeks of screening visit
• lung disease other than asthma
• significant medical comorbidity
• current smoker or ex-smoker with significant smoking history
• currently pregnant or breastfeeding

Trial design

Primary purpose: Other

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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26 participants in 4 patient groups

Mannitol challenge

Experimental group

Description:

Mannitol challenge performed per standard mannitol challenge procedure with deep inhalation technique

Treatment:

Procedure: Deep inhalation technique

Drug: Mannitol

Mannitol challenge w/ TBI

Experimental group

Description:

Mannitol challenge performed per standard mannitol challenge procedure except with tidal breathing technique

Treatment:

Procedure: Tidal breathing technique

Drug: Mannitol

Methacholine challenge w/ DI

Experimental group

Description:

Methacholine challenge performed per standard 2-minute tidal breathing challenge procedure except with deep inhalation technique

Treatment:

Drug: Methacholine

Procedure: Deep inhalation technique

Methacholine challenge

Experimental group

Description:

Methacholine challenge performed per standard 2-minute tidal breathing challenge procedure (tidal breathing technique)

Treatment:

Drug: Methacholine

Procedure: Tidal breathing technique