Influence of Predicted FEV₁ on Bronchodilator Response in Asthmatic Patients

Abstract

Background: There is currently disagreement on the way of expressing the reversibility of airflow obstruction, with some evaluations based on the initial FEV₁ while others use predicted FEV₁ (according to age, gender and height). Objectives: To test the relevance of expressing bronchodilator response as a percentage of predicted FEV₁, we evaluated the influence of morphological data on the response to bronchodilators in a population with a large range of predicted values. Methods: We measured the change in FEV₁ after inhalation of 200 µg of salbutamol in 30 asthmatic subjects (15 adults and 15 children) in whom predicted FEV₁ ranged between 1.13 and 4.10 liters and analyzed the respective influence of initial and predicted FEV₁on bronchodilator response. Results: We have shown a significant relationship between the absolute variation in FEV₁, in liters, and predicted FEV₁ (p = 0.0019). There was also a significant relationship between the absolute variation in FEV₁ and initial FEV₁, in liters (p = 0.02). This relationship was no longer significant (p = 0.8) when the variation and initial FEV₁ were both expressed as percentages of predicted FEV₁. In addition, multiple regression analysis showed that predicted FEV₁ was the only independent variable correlating with the response to bronchodilators. Conclusion: This study showed the influence of predicted FEV₁ on bronchodilator response. This result provides an additional argument for expressing bronchodilator response as a percentage of predicted FEV₁.

Bronchial hyperresponsiveness to methacholine/AMP and the bronchodilator response in asthmatic children

“…It has been suggested that relating the DFEV1 to the predicted value may be more appropriate [27], because it eliminates the influence of not only the initial value but also sex, age and height. In the present study, however, a closer relationship of BDR with AMP PC20 than with methacholine PC20 persisted (p50.029 for comparison of correlation coefficients), even when DFEV1 was evaluated based on the predicted value instead of the initial value.…”

Diagnostic Spirometry in Primary Care: Proposed standards for general practice compliant with American Thoracic Society and European Respiratory Society recommendations. A General Practice Airways Group (GPIAG)1 document, in association with the Association for Respiratory Technology & Physiology (ARTP)2 and Education for Health3 1www.gpiag.org 2 www.artp.org 3 www.educationforhealth.org.uk

“…108,109,117 A change > 12% predicted and >200 mL 109,[133][134][135][136][137] during a single test session is accepted as denoting a statistically significant improvement. One guideline 8 suggested, "on an arbitrary basis", that > 400mL could be adopted as a clinically significant improvement following bronchodilation; however, against the background of published results [133][134][135][136][137] it seems that this level is very strict indeed. In a clinical database (Erasmus University Medical Centre, Lung Department, Rotterdam) of 4,352 patients tested pre-and postbronchodilator, a change in FEV 1 exceeding 400 mL was observed in 3.35% of patients, and > 200 mL in 14.96% of patients.…”

“…As children have smaller lungs it has been suggested that the 200 mL criterion should be dropped. [135][136][137] Recommendation: Post-bronchodilator spirometry: i) In the case of airway obstruction it is good practice to include post-bronchodilator spirometry testing, especially in newlydiagnosed patients. ii) In the case of diagnosis of COPD: postbronchodilator spirometry is recommended by the GOLD and ERS/ATS COPD guidelines and is required to satisfy the requirements of the UK payment system for GPs -the Quality Outcome Framework (QOF).…”

Interferon-αcon-1 Treatment of Three Patients with Severe Glucocorticoid-Dependent Asthma

“…Results of chest radiography and high-resolution computed tomography (HR-CT) were normal, and skin prick test results were negative. Pulmonary function tests [9] under maximal anti-obstructive medication including 100 mg methylprednisolone showed an obstructive pattern with forced expiratory volume in 1 s (FEV1) of 79%, Tiffeneau index (FEV1/inspiratory vital capacity) of 68%, total lung capacity (TLC) of 120%, residual volume (RV) of 134% and airway resistance of 171% of the predicted values. Carbon monoxide transfer factor (DLCO) and a DLCO corrected for alveolar volume (DLCO/VA) were normal.…”