Correlation of Airway Hyper-responsiveness with Obstructive with Spirometric Indices and FEV1 > 90% Predicted

Abstract

Current published guidelines on spirometry interpretation suggest an elevated FVC and FEV(sub 1) > 100% of predicted with an obstructive ratio may represent a physiological variant. There is minimal evidence whether this finding can be indicative of symptomatic airways obstruction. Pulmonary function testing databases for a 4-year period were retrospectively reviewed. All technically adequate spirometry studies were included, based on these criteria: FEV(sub 1) > 90% of predicted, and FEV(sub 1)/FVC below the lower limit of normal, based on 95th percentile confidence intervals. Clinical indications for testing were noted. Testing for postbronchodilator response, lung volumes, and methacholine challenge tests were reviewed for evidence of airway hyper-responsiveness (AHR). Comparisons were made between symptomatic versus asymptomatic individuals and FEV(sub 1) values less than or greater than 100% of predicted. RESULTS: A total of 280 studies were analyzed. During their clinical evaluation, 192 patients (69%) had post-bronchodilator spirometry recorded, 63 patients (23%) had lung volumes, and 36 patients (11%) completed methacholine challenge testing. Indications for spirometry included 193 symptomatic patients and 87 asymptomatic patients. Nearly 28% of patients with postbronchodilator testing met criteria for AHR. No differences in AHR were found between the symptomatic and asymptomatic groups. The majority of patients (77%) with AHR had an FEV(sub 1) < 100%, when compared to patients with an FEV1 > 100%. CONCLUSIONS: A normal FEV(sub 1) 90% of predicted with obstructive indices may not represent a normal physiological variant, as 28% of patients were found to have underlying AHR. These findings suggest that clinicians should evaluate for AHR, especially in symptomatic patients, even if the FEV(sub 1) is > 90% of predicted.

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Apr 01, 2012
Accession Number
ADA597903

Entities

People

  • David G. Bell
  • George H. Kotti
  • Michael J. Morris
  • Pedro F. Lucero
  • Tokunbo Matthews

Tags

DTIC Thesaurus Topics

  • Active Duty
  • Air Force
  • Carbon Monoxide
  • Databases
  • Dielectric Gases
  • Diseases And Disorders
  • Flow
  • Information Science
  • Lung Diseases
  • Medical Personnel
  • Monoxides
  • Pain
  • Pulmonary Function
  • Respiration Disorders
  • Respiratory Physiological Phenomena
  • Standards
  • Statistical Analysis

Fields of Study

  • Medicine

Readers

  • Cardiovascular Physiology
  • Gulf War Illness and Chronic Multisymptom Illness in Veterans.
  • Tribology (the study of the boundary interaction between sliding surfaces, lubrication, wear and friction).