Exercise-induced Bronchoconstriction Diagnostics: Impact of a Repeated Exercise Challenge Test

Exercise-induced Bronchoconstriction Diagnostics: Impact of a Repeated Exercise Challenge Test

The purpose of this study is to increase the knowledge of the possible diagnostic effect of exercise induced bronchoconstriction performing a repeated exercise challenge test.

Prior studies have shown that the intensity influences the sensitivity of exercise challenge tests (ECT) and that a heart rate-based protocol does not ensure sufficient exercise intensity to induce bronchoconstriction. It is not common clinical practice to perform a pre ECT to establish maximal heart rate or maximal oxygen uptake. The heart rate formula recommended by ATS (HRmax= 220-age) is usually applied to determine recommended intensity of the ECT. Conducting a second ECT, based on the knowledge of the first test, introduce the possibility to adjust the intensity on an individual basis. In addition, based on clinical experience, patients may seem reluctant to perform maximal the first time they undergo an ECT on a treadmill. The hypothesis is that patients are less reluctant to perform maximal the second time they undergo the test when they are more accustomed to the procedure and the treadmill by itself.

Inclusion Criteria:

• Referred to Klinikk for allergi og luftveissykdommer

• Meet at least 3 out of 5 criteria (symptoms related to exercise):

  1. Cough during exercise or within 5 minutes after exercise
  2. Wheeze during exercise or within 5 minutes after exercise
  3. Heavy breathing, expiratory in particular, during exercise or within 5 minutes after exercise (duration 5 minutes or more)
  4. Improvement of physical fitness/breath is lacking despite of exercise intensification
  5. Chest tightness during or after exercise

• Patients former diagnosed with-and treated for asthma who have symptoms of EIB are included in the study.

Exclusion Criteria:

• Ongoing respiratory infection or recent respiratory infection, judged by the responsible doctor to be of importance of the result
• The inability to perform an Exercise challenge test with maximum effort