oRioN: Cough Response to Different Challenge Protocols & Devices (v1)
Research type
Research Study
Full title
A Comparison and Validation Study of Cough Challenge Responses Evoked Using Different Hypotonic Saline Protocols and Nebulizer Systems
IRAS ID
368306
Contact name
Jacky Smith
Contact email
Sponsor organisation
University of Manchester
Clinicaltrials.gov Identifier
72947, CPMS; G90328, MFT Contract Code
Duration of Study in the UK
1 years, 6 months, 0 days
Research summary
Chronic cough (cough that lasts >8 weeks) affects 1 in 10 people, has no-positive diagnostic tools and substantially effects quality of life. Cough challenge tests are used in research to measure how sensitive a person’s cough reflex is and investigate underlying mechanisms. Cough challenge using hypotonic saline (low chloride, low sodium salty water) has been shown to distinguish between healthy volunteers and people with ‘refractory or unexplained’ chronic cough (RUCC).
However, the challenge needs refining if we are to continue using it as a research tool, and before this challenge can be investigated for any clinical utility in aiding diagnosis of RUCC. Secondly, the nebuliser and consumables currently used in hypotonic saline cough challenge are being withdrawn from use, so an alternative nebuliser must be identified.
This study therefore aims to understand whether the current hypotonic saline cough challenge methodology can be refined while retaining its ability to identify patients with RUCC versus healthy volunteers. Phase A of the study will investigate whether we can shorten the hypotonic cough challenge protocol. This will be done by comparing how much people cough when asked to breathe in different amounts of saline solutions, compared to the original challenge. Phase B will investigate whether an alternative device can be used to conduct a hypotonic saline cough challenge. This will be done by comparing the cough response to hypotonic cough challenge using the original device, versus an alternative device.
Patients with refractory or unexplained chronic cough (RUCC) will be recruited from specialised cough clinics at Manchester Foundation Trust (MFT) and healthy volunteers will be recruited from across the University of Manchester and MFT. Visits will be conducted at the NIHR Manchester Clinical Research Facility.REC name
London - Camberwell St Giles Research Ethics Committee
REC reference
26/LO/0556
Date of REC Opinion
24 Jul 2026
REC opinion
Favourable Opinion