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Completed

NCT Number: NCT05034367

Reference Ranges for the Cough Responsiveness to Inhaled Mannitol

Cough is the most common reason why people seek medical attention in developed countries. The main mechanisms for prolonged cough are hypersensitivity of the cough reflex arc, sputum production, and constriction of the airway smooth muscles. Recognition of the mechanism in each cough patient is essential for the efficient management of prolonged cough. At present, there are no feasible tests for everyday clinical work to recognize cough reflex arc hypersensitivity.

Mannitol test was originally developed for asthma diagnostics. We have recently shown that it can also be used to investigate hypersensitive cough reflex arc. The purpose of the present study is to create reference ranges for normal cough responsiveness to inhaled mannitol. Without them, the test cannot be utilized in everyday clinical work. For that purpose we will perform mannitol test in 140 subjects, who are at least 18 years old and without any chronic respiratory symptoms or disorders. The subjects will be recruited in three centers: University of Eastern Finland and: John Hunter Hospital in Australia.The material will be collected 1.9.2021-31.12.2023. We apply funding for both personnel and material expences, to carry out this study.

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Key information

Conditions

Cough Pathological Conditions, Signs and Symptoms Respiration Disorders Respiratory Tract Diseases Signs and Symptoms Signs and Symptoms, Respiratory

Age range

18 year–90 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

John Hunter Hospital, Newcastle, New South Wales, Australia

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Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • age 18 years or older
  • capable to understand the purpose of the study
  • female/male ratio approximately 50%/50% in both of the following age groups:
  • 50% aged 18- 50 yrs, and 50 % aged 51 - 90 years

Exclusion criteria

  • Current daily smoking
  • Ex-smoking with a greater than 10 pack years' daily smoking history or with stopping of daily smoking less than one year ago
  • Pregnancy and breastfeeding
  • A doctor's diagnosis of any respiratory diseases, including both upper and lower airway diseases, lung parenchymal diseases and the sleep apnoea syndrome
  • A doctor's diagnosis of gastro-oesophageal reflux disease or symptoms suggestive of it
  • Current use of angiotensin-converting enzyme inhibitors
  • Upper respiratory tract infection ('flu') within 4 weeks
  • Any current (within 4 weeks) cough 8
  • Chronic (over 2 months' duration) cough during the last 12 months
  • Wheezing during the last 12 months
  • Attacks of shortness of breath or cough at night during the last 12 months
  • Symptoms of rhinitis in a prolonged fashion during the last 12 months
  • Heartburn or regurgitation once a week or more often during the last 3 months
  • Abnormal anatomy of the respiratory organs, which may affect the deposition of the mannitol powder
  • Any previous operations to the respiratory organs that can affect the deposition of the mannitol powder
  • Unable to provide written informed consent to participate in the study

Treatment and study plan

Mannitol challenge

Diagnostic Test

Inhalation challenge with dry powder of mannitol with a maximal cumulative dose of 635 mg

Primary outcomes

  1. Cough-to-dose ratio

    Time frame: Coughs are recorded during the 60 seconds after each mannitol dose

    calculated as the number of coughs per 100 mg of total cumulative dose of mannitol

Sponsors and collaborators

Lead sponsor

Kuopio University Hospital

Other

Collaborators

  • John Hunter Hospital

Registry information

Important dates

Study start
2022
Primary completion
2023
Study completion
2023
First posted
Sep 5, 2021
Registry last updated
Sep 19, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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