Acute bronchodilator trials in chronic obstructive pulmonary disease

Area of Science:

• Pulmonary Medicine
• Respiratory Pharmacology

Background:

• Short-term bronchodilator trials are standard for assessing stable chronic obstructive pulmonary disease (COPD).
• Uncertainty exists regarding the comparative efficacy of beta-agonists and anticholinergics, their ability to predict corticosteroid response, optimal result expression, and influence of age or allergy.

Purpose of the Study:

• To evaluate the equivalence of FEV1 response to salbutamol and ipratropium in COPD patients.
• To determine the predictive value of acute bronchodilator response for corticosteroid responsiveness.
• To assess the impact of age and allergic status on bronchodilator response.

Main Methods:

• 100 stable COPD patients underwent spirometry before and after nebulized salbutamol or ipratropium.
• Patients received oral prednisolone for 2 weeks, with spirometry repeated.
• Allergic status was assessed via IgE, RAST, and skin prick testing.

Main Results:

• 33% failed to bronchodilate, while 16%, 17%, and 34% responded to salbutamol only, ipratropium only, or both, respectively.
• Corticosteroid improvement was predicted by acute bronchodilator response (salbutamol 90% specific, ipratropium 84% specific).
• Neither age nor allergic status correlated with FEV1 changes after bronchodilators.

Conclusions:

• High-dose nebulized bronchodilator testing in COPD identifies a significant proportion of patients with partially reversible airflow obstruction.
• The response to bronchodilators can predict improvement with corticosteroids.
• Age and allergic status do not appear to influence bronchodilator response in this COPD cohort.