(image: flickrCC)

Why do we test chronic obstructive pulmonary disease (COPD) patients for bronchodilator responsiveness (besides getting to charging a few extra bucks for it)?

If I am reading this article right, the answer is, there's no good reason. Consider this:

• Bronchodilator responsiveness (BDR) or the lack thereof does not distinguish COPD from asthma.

• Bronchodilator repsonsiveness can come and go on different visits by the same patient (38-52% intra-individual variability).

• There is no consensus on the standardization of testing (which drug, dose, definition of response) or the interpretability of the results in COPD patients.

• The absence of a BDR does not mean a patient won't get a good benefit from bronchodilator therapy (especially long-acting). In clinical trials, those with bronchodilator repsonses did get a greater increase in lung function than those without a BDR, but those without a BDR had stat.significant improvements in dyspnea and quality of life with bronchodilator therapy compared to placebo. So you should never withhold bronchodilator therapy based on the lack of a response on testing. Guidelines argue against checking BDR for this purpose.

The main thing I took from this well-written article by Hanania et al was that checking bronchodilator response in COPD patients only has a downside: it can spur you to wrongly deny or discourage bronchodilator therapy.

So ... is there any good reason to check for a bronchodilator response in someone with COPD, ever (outside of a clinical trial or research registry)?

Hanania NA et al. Bronchodilator Reversibility in COPD. CHEST 2011;140(4):1055-1063.