Diagnosing Asthma- Bronchoprovocation Challenge Testing

When Is Bronchoprovocation Challenge Testing Needed In Diagnosing Asthma

Bronchoprovocation Challenge Testing
Methacholine- Bronchoprovocation Challenge Testing. Photo © Flickr user Laurie Blundell

What Is Bronchoprovocation Challenge Testing

Bronchoprovocation tests help asthma care providers make a diagnosis of asthma. In general, you will inhale a nebulized solution or perform exercise to see if you develop symptoms of asthma or airflow obstruction measured by spirometry. If you develop either, your airways are hyperresponsive. Your asthma care provider may challenge you with:

  • Methacholine
  • Histamine
  • Cold Air
  • Exercise

Why Would My Asthma Provider Order a Bronchoprovocation Challenge?

A common scenario for asthma care providers to order bronchoprovocation testing is if you have symptoms that suggest asthma, but normal spirometry testing and no response to rescue medications. In this scenario you are not likely eliciting other symptoms of asthma and airway hyperresponsiveness may be your only symptom. Obstruction of airflow in your lungs can be provoked by inhaling aerosols known to elicit asthma symptoms and cause airway narrowing and irritation.

If your doctor decides that a challenge is appropriate but your lungs fail to demonstrate hyperresponsiveness, a diagnosis of asthma is less likely. If you do demonstrate airway hyperresponsiveness, the degree to which your test is positive is associated with the severity of your asthma. If you are responsive but do not have much in the way of symptoms today, you are likely at risk of asthma in the future.

If your asthma diagnosis is in doubt, an objective measure of asthma is important. Consider this scenario. If you have normal lung function tests and typical intermittent asthma symptoms, a clear response to treatment is probably adequate diagnostically and reasonable to you as a patient and your insurance company.

However, would you want to be placed on a lifetime of medicine potentially if the question "Do I really have asthma?" remained?

Bronchoprovocation testing may also be performed in the following scenarios:

  • Typical asthma symptoms and normal pulmonary functions, but no response to albuterol. Bronchoprovocation testing is the only way a diagnosis of asthma will be made.
  • Patients with atypical symptoms and present with a complaint of only waking up at night without any typical symptoms such as wheezing, chest tightness, cough, or shortness of breath.
  • Patients with ill-defined symptoms such as cough. Cough is a common complaint to a physician's office. When there is no objective evidence of airway hyperresponsiveness and no other explanation of the symptom, a diagnosis of asthma should be considered,
  • Patients who might be seriously harmed by bronchospasm if there was a sudden episode that cannot be prepared for such as a scuba diver or military personnel.
  • Patients who may have occupational asthma, reactive airways dysfunction syndrome, or irritant-induced asthma.

    How is Bronchoprovocation Testing Preformed?

    You will begin by inhaling a nebulized aerosol with one of the previously mentioned agents as if you were taking a normal breathing treatment. The nebulized treatments will be repeated at specific time increments. You will perform spirometry before and after each nebulized treatment, and your asthma care provider will look at the decrease in FEV1.

    What Do My Results Mean?

    A decline in FEV1 of 20% from your baseline reading is considered a positive test. If your asthma care provider suspects asthma, you may be started on an asthma treatment.

    Hyperresponsiveness reliably discriminates between patients with asthma from patients without asthma. Bronchoprovocation testing has a high negative predictive value. Thus, if you have a negative test, it is unlikely you have asthma.

    Bronchoprovocation Testing Is Not For Everyone

    Not everyone should have bronchoprovocation challenge testing because there is a risk it may lead to a potentially severe asthma attack. If you have any of the following, you need to discuss with your asthma care provider whether or not testing is appropriate for you:

    • Moderate (FEV1 <60% predicted) or severe (FEV1 of < 50% of predicted) airway obstruction
    • A heart attack in the last 3 months
    • Uncontrolled hypertension (systolic > 200 mm Hg or diastolic > 100 mm Hg)
    • Aortic aneurysm
    • Pregnant or nursing mother
    • Myasthenia Gravis

    Certain medications need to be stopped or modified before testing to ensure a good test or specific safety reasons. Tiotropium, for example, needs to be stopped a week before testing while citrizine needs to be stopped 48 hours before and montelukast 24 hours before testing.


    National Heart, Lung, and Blood Institute. Expert Panel Report 3 (EPR3): Guidelines for the Diagnosis and Management of Asthma

    Clinical Pulmonary Function Testing, Exercise Testing, and Disability Evaluation. In Chest Medicine: Essentials Of Pulmonary And Critical Care Medicine. Editors: Ronald B. George, Richard W. Light, Richard A. Matthay, Michael A. Matthay. May 2005, 5th edition.

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