Post bronchodilator test

The post bronchodilator test, also commonly referred to as a reversibility test, is a test that utilizes spirometry to assess possible reversibility of bronchoconstriction in diseases such as asthma.

Indications

This procedure is indicated in the diagnosis and follow-up of asthma, and in the differentiation between asthma and COPD.

Procedure

An initial spirometry is performed to assess the patient's native respiratory status. The patient will be asked to take a deep breath and then blow into the mouthpiece of the spirometer as hard as you can. This is a baseline measurement. A dose of bronchodilator medication is administered by means of inhaler or nebulizer. You will wait about 15 minutes and then the spirometry is repeated. An increase in FEV1 of >200ml is considered a positive result. Bear in mind, however, that this number does not apply to children, and that it can differ depending on the patient's native result; small patient's with pulmonary fibrosis, restrictive lung disease etc. will have a measurably lower FEV1 than healthy average-sized adults. This can give a false positive result of the test.