TransMEM Gas Exchange -- Project 1, Aim 2

Completed · Phase 1

Conditions studied: Middle Ear Disease, Nasal Allergy

In brief

This study will determine if exposure to an allergy material (ragweed) or exposure to an allergic-symptom-provoking substance (histamine) and medications typically used to decongest the nose changes the rate of blood-flow in the lining of the middle-ear. Otitis media (the build-up of water-like fluid in the middle-ear airspace) may occur if the blood flow in the lining of the middle-ear is too high and may be prevented if a way could be found to lower the blood flow in persons susceptible to the disease. Middle-ear blood flow is measured indirectly by measuring the change in middle-ear pressure while a person breathes a gas mixture containing nitrous oxide ("laughing gas"). In this study, 4 groups of subjects will be entered and middle-ear pressure in persons breathing a mixture of 50% Oxygen, 50% Nitrous Oxide ("laughing gas")will be measured after exposure to one of four substances (ragweed, histamine,an oral decongestant, a decongestant nasal spray) and a fake medication (placebo) at separate test sessions. All subjects will have one set of 2 x-rays of the middle ears and mastoids. The group exposed to ragweed will require 3 study visits while the other 3 groups will have 2 study visits. From this information middle-ear blood flow will be calculated. This will help determine the relationship between what happens in the nose and what happens in the middle ear.

Key facts

Study ID

NCT01925729

Run by

Cuneyt M. Alper

People needed

84

Starts

2013-10-01

Expected to finish

2019-03-22

Last updated by the study team

2020-02-07

Who can join

Age: 18 and older, up to 50. Sex: any. Healthy volunteers: accepted.

You may qualify if…

• healthy
• no evidence of otitis media at entry
• bilaterally intact tympanic membranes
• ragweed arm: history of symptomatic ragweed allergy and Class 2 positive on RAST testing with or without other allergic sensitivities by history

You may not qualify if…

• craniofacial syndrome (ef, cleft palate)
• Use of prescription medications (except for birth control) in the 1 month prior to entry;
• Use of over-the-counter allergy medication within 2 weeks before challenge (Experiments 1, 2 only);
• Use of over-the-counter decongestants (nasal or oral) within 2 weeks before challenge (Exp 3,4 only)
• Elevated blood pressure (>140/90);
• Individuals with any pulmonary or cardiac problems, including asthma;
• Individuals who are pregnant or who are planning to become pregnant during the period of study;
• Individuals who had immunotherapy for ragweed allergy at any time (Experiment 1 only);
• Individuals who used any experimental medication or treatment within 3 months of screening;
• Individuals with extant unilateral or bilateral otitis media as documented by otoscopy or tympanometry;
• Individuals with abnormally low tympanic membrane mobility, eg Type B tympanogram;
• Individuals reporting a previous adverse experience with breathing gas mixtures containing N2O (e.g. during dental procedures);
• Individuals who have upper respiratory ("cold") symptoms or allergic rhinitis symptoms (may be rescheduled);
• Individuals with single or multiple allergic sensitivities by screening history (Experiment 2 only)

Where it is running

• Middle Ear Physiology Laboratory, University of PIttsburgh — Pittsburgh, Pennsylvania, United States

Full record on ClinicalTrials.gov

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