Description of the Test

Your child will first perform a breathing test to determine their baseline lung function. During the test, your child will be asked to inhale by a mist aerosol, doses of methacholine a drug which may cause the airways to narrow. The test starts with a very small dose of methacholine. Doses will be gradually increased and a breathing test will be repeated after each dose to measure the degree of narrowing of the airways. The testing will be completed if your child either shows signs that the airways are narrowing on the breathing test or reaches the highest dose used in the test without airway narrowing.

Length of Test

The test may take up to 90 minutes

Preparing Your Child for the Test

There is a list of medications that may decrease your child's response to the methacholine and should be avoided only if possible prior to testing.

Check with your child's physician before stopping any medication prior to this test, or call the PFT Laboratory at 513-636-8959.

Possible Side Effects of the Test

Thousands of methacholine challenge test have been performed in Cincinnati Children's pulmonary function laboratory and elsewhere with no serious side effects. Methacholine may cause airway narrowing, and rarely symptoms such as coughing, chest tightness, or shortness of breath; however, all precautions are taken including continuous monitoring by the pulmonary function technologist. If the test shows that there is airway narrowing, your child will be given an inhaled bronchodilator to relieve symptoms.