Bronchodilator Response in FVC Is Larger and More Relevant Than in FEV 1 in Severe Airflow Obstruction
| Autor: | Jean Bourbeau, Philip H. Quanjer, Frans W. Mertens, Gregg L Ruppel, Rogelio Pérez-Padilla, Arnulf Langhammer, Wan C. Tan, Maureen P. Swanney, Abhishek Krishna, Ane Johannessen, Ana M. B. Menezes, Fernando C. Wehrmeister |
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| Přispěvatelé: | Pediatrics, Pulmonary Medicine |
| Rok vydání: | 2017 |
| Předmět: |
Pulmonary and Respiratory Medicine
medicine.medical_specialty medicine.drug_class Hyperinflation Respiratory physiology Standard score Critical Care and Intensive Care Medicine 03 medical and health sciences FEV1/FVC ratio 0302 clinical medicine Internal medicine Bronchodilator medicine 030212 general & internal medicine Asthma business.industry respiratory system Airway obstruction medicine.disease respiratory tract diseases 030228 respiratory system Cardiology Physical therapy Analysis of variance Cardiology and Cardiovascular Medicine business circulatory and respiratory physiology |
| Zdroj: | Chest, 151(5), 1088-1098. American College of Chest Physicians |
| ISSN: | 0012-3692 |
| Popis: | Background Recommendations on interpreting tests of bronchodilator responsiveness (BDR) are conflicting. We investigated the dependence of BDR criteria on sex, age, height, ethnicity, and severity of respiratory impairment. Methods BDR test data were available from clinical patients in the Netherlands, New Zealand, and the United States (n = 15,278; female subjects, 51.7%) and from surveys in Canada, Norway, and five Latin-American countries (n = 16,250; female subjects, 54.7%). BDR calculated according to FEV 1 , FVC, and FEV 1 /FVC was expressed as absolute change, a percentage of the baseline level (% baseline), a percentage of the predicted value (% predicted), and z score. Results Change (Δ) in FEV 1 and FVC, in milliliters, was unrelated to the baseline value but was biased toward age, height, sex, and level of airways obstruction; ΔFEV 1 was significantly lower in African Americans. In 1,106 subjects with low FEV 1 (200-1,621 mL) the FEV 1 increased by 12% to 44.7% relative to baseline but z score attenuated the bias and made the 200-mL criterion redundant, but reduced positive responses by half. ΔFEV 1 % baseline increased with the level of airflow obstruction but decreased with severe obstruction when expressed as z scores or % predicted; ΔFVC, however expressed, increased with the level of airflow obstruction. Conclusions Expressing FEV 1 responsiveness as % baseline spuriously suggests that responsiveness increases with the severity of respiratory impairment. Expressing change in FEV 1 or FVC as % predicted or as z scores eliminates this artifact and renders the required 200-mL minimum increase redundant. In severe airways obstruction ΔFVC should be critically evaluated as an index of clinically important relief of hyperinflation, with implications for bronchodilator drug trials. |
| Databáze: | OpenAIRE |
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