| Description: | To determine if the patient's airways (bronchial tubes) are overly sensitive, or hyper reactive ("twitchy") when breathing a drug called methacholine. This drug causes the airways to narrow or constrict. |
| Test: | The patient will perform breathing tests in between inhaling gradually increasing doses of methacholine. Spirometry testing or measurement of airway resistance will be performed following each dose of methacholine to measure the change in the ability to breathe out forcefully. The resistance to airflow in and out of your airways is measured in a body plethysmograph (a chamber like a telephone booth) used to measure the resistance of air moving in and out of the airways when the patient pants gently. These tests will be done 3 - 5 minutes after the patient inhales each dose of methacholine. If the tests show that the airways are overly sensitive to the methacholine a bronchodilator will be administered by inhaler to completely reverse the effects of the methacholine. |
| Length of Time: | Approximately 1.5 hours. |
| Preparation: | Eat a regular breakfast/lunch and drink plenty of fluids. Do not take any antihistamines or bronchodilators for 12 hours prior to the test. Be sure to discuss proper preparation for the test with the Pulmonary Fellow prior to scheduling your appointment by calling (415)476-8493. |