[Bronchodilatation during spirometry : indications, realization and interpretation]

Spirometry with response to short-acting bronchodilators is a key element in the diagnostic work-up of patients with obstructive airways diseases and should be systematically assessed. Response to bronchodilators (RBD) is useful to differentiate asthma from COPD and to grade the severity of obstruction in COPD cases. RBD should not be used to decide for a bronchodilator therapy. An increase in Forced Expiratory Volume in 1 sec (FEV1) or Forced Vital Capacity (FVC) by > 200 ml and 12 % of baseline value is considered as criteria for significant bronchodilator response. With the exception of asthma diagnostic work-up, inhaled therapy should not be interrupted before spirometry. Paradoxical loss of lung function after administration of beta 2 agonists is rarely observed. When present, choice of an alternative bronchodilator agent should be considered.