RecruitingInterventional

oRIoN: An investigation into whether the methodology used in hypotonic saline cough challenge can be refined

A long-lasting cough that does not get better with usual treatment can have a huge impact on daily life. Researchers use a test called a 'cough challenge' to understand why this happens. During this test, a person breathes in a fine mist of weak salty water through a mouthpiece, which helps doctors measure how sensitive their cough reflex is. This study, called oRIoN, takes place at Wythenshawe Hospital in Manchester. The team wants to find out if they can make this test shorter and simpler. They also need to test a newer breathing machine, because the older model is being retired. The trial is open to adults with an unexplained chronic cough, as well as healthy volunteers. Taking part involves clinic visits for breathing tests and inhaling the mist while a monitor counts coughs. It does not test any new drugs.

At a glance

Status

Recruiting

Sponsor

University of Manchester

Enrolment target

114

Start

05 Oct 2026

Estimated completion

19 Jan 2028

Chronic cough

What is this study about?

A chronic cough is defined as a cough that lasts for eight weeks or longer. For some people, standard treatments do not work, and doctors cannot find a clear cause. This is known as refractory chronic cough. People living with this condition often cough hundreds of times a day, which can cause chest pain, exhaustion, and embarrassment in social situations.

To study chronic cough, scientists use a tool called a cough challenge. Participants breathe in a mild mist made of water with low levels of salt. Because people with chronic cough have hypersensitive airways, they cough more easily when breathing in this mist than healthy people do. This helps researchers measure how sensitive a person's lungs are and see how well future cough medicines might work.

Right now, the test takes quite a long time to complete. In addition, the equipment currently used to make the mist is no longer going to be made, so doctors need to find a suitable replacement. This study aims to create a shorter version of the test and check that a newer machine gives the same dependable results. By refining this method, the team hopes to make it easier for clinics to diagnose and study chronic cough in the future.

Key takeaways

The oRIoN study aims to make cough sensitivity tests faster, simpler, and up to date.
Open to adults aged 18+ with unexplained chronic cough and healthy volunteers.
Involves breathing in a harmless, mild salty mist while a small device records coughs.
Does not test any experimental drugs or alter your usual prescriptions.
Held at the NIHR Clinical Research Facility at Wythenshawe Hospital in Manchester.

Who may be eligible?

The study is open to two groups of adults aged 18 and over. The first group includes people who have a long-term cough that has not responded to treatment, diagnosed by a specialist. The second group is made up of healthy volunteers who have no history of lung or breathing conditions. All participants must have normal results on a routine breathing test.

To ensure results are clear and safe, participants must be non-smokers. If you used to smoke or vape, you must have quit at least six months ago and have a relatively light smoking history.

You cannot take part if you have asthma, are pregnant, or are breastfeeding. You also cannot participate if you take certain medicines that can change how much you cough. These include certain blood pressure tablets called ACE inhibitors, some nerve-pain medicines, strong opioid painkillers, and certain antidepressants.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Are you aged 18 or over?
Do you have a persistent cough that has not responded to treatment, OR are you a healthy volunteer with no lung problems?
Are you a non-smoker, or did you quit smoking and vaping at least 6 months ago?
Can you confirm you do not have asthma?
Are you free from medications like ACE inhibitors, strong painkillers, or tricyclic antidepressants?
Can you attend appointments at Wythenshawe Hospital in Manchester?

Answer every question to see your result.

What does participation involve?

The study takes place at the Clinical Research Facility at Wythenshawe Hospital in Manchester and is divided into two separate parts.

Phase A involves five clinic visits spaced two to seven days apart, followed by a short phone call. Each visit takes about one hour. During these visits, researchers will check your lungs with a simple blowing test. You will wear a small sound monitor to count your coughs and breathe in different strengths of salty mist through a mouthpiece. A 15-minute follow-up phone call completes this phase.

Phase B involves three clinic visits lasting one to one-and-a-half hours each, plus a final phone call. This phase tests whether a new breathing machine works just as well as the older machine. Visits one and two are two to seven days apart, while visit three happens two to four weeks later.

You do not have to take part in both phases. No new medications are being prescribed; the study only tests the breathing challenge procedure itself.

Potential risks and benefits

There is no direct medical benefit to your health from taking part, but your time will help doctors improve testing and treatments for people with severe coughs in the future. Inhaling the salty mist will make you cough, and it may temporarily tickle your throat. Very rarely, the mist can cause temporary tightness in the chest. To keep you safe, medical staff test your breathing before and after each challenge and keep a reliever inhaler ready if needed. People with asthma are excluded to lower this risk. You are free to stop any test or leave the study at any time without giving a reason, and your regular NHS medical care will not be affected.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

Manchester University NHS Foundation Trust
City only
Manchester, England

Common questions

Will taking part in this study cure my chronic cough?

No. This study does not provide treatment for your cough. It is designed to test and improve the research tools doctors use to understand cough sensitivity.

Is the salty mist harmful to my lungs?

No. The weak salt solution has been safely used in medical research for many years. It triggers coughing, but the effect is brief and wears off quickly.

Do I have to take part in both Phase A and Phase B?

No. You can choose to join only Phase A. You can let the team know if you are interested in joining Phase B as well, but it is completely optional.

What happens if I feel uncomfortable during the breathing test?

You are in control at all times. You can ask to pause or stop the test whenever you wish. Qualified medical staff will be with you throughout the visit.

Will this study affect my usual NHS appointments?

No. Your participation is completely voluntary and separate from your standard NHS care. Leaving the study will never change how doctors treat you.

How to find out more

Shannon Galgani

cough.research@manchester.ac.uk +44 (0)161 291 5031 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.