Lung clearance index is a repeatable and sensitive indicator of radiological changes in bronchiectasis.

Abstract

RATIONALE:

In bronchiectasis there is a need for improved markers of lung function to determine disease severity and response to therapy.

OBJECTIVES:

To assess whether the lung clearance index is a repeatable and more sensitive indicator of computed tomography (CT) scan abnormalities than spirometry in bronchiectasis.

METHODS:

Thirty patients with stable bronchiectasis were recruited and lung clearance index, spirometry, and health-related quality of life measures were assessed on two occasions, 2 weeks apart when stable (study 1). A separate group of 60 patients with stable bronchiectasis was studied on a single visit with the same measurements and a CT scan (study 2).

MEASUREMENTS AND MAIN RESULTS:

In study 1, the intervisit intraclass correlation coefficient for the lung clearance index was 0.94 (95% confidence interval, 0.89 to 0.97; P < 0.001). In study 2, the mean age was 62 (10) years, FEV1 76.5% predicted (18.9), lung clearance index 9.1 (2.0), and total CT score 14.1 (10.2)%. The lung clearance index was abnormal in 53 of 60 patients (88%) and FEV1 was abnormal in 37 of 60 patients (62%). FEV1 negatively correlated with the lung clearance index (r = -0.51, P < 0.0001). Across CT scores, there was a relationship with the lung clearance index, with little evidence of an effect of FEV1. There were no significant associations between the lung clearance index or FEV1 and health-related quality of life.

CONCLUSIONS:

The lung clearance index is repeatable and a more sensitive measure than FEV1 in the detection of abnormalities demonstrated on CT scan. The lung clearance index has the potential to be a useful clinical and research tool in patients with bronchiectasis.

• Authors: Stephen A Rowan, Judy M Bradley, Ian Bradbury, John Lawson, Tom Lynch, Per Gustafsson, Alex Horsley, Katherine O'Neill, Madeleine Ennis, J Stuart Elborn
• Journal: American journal of respiratory and critical care medicine (Am J Respir Crit Care Med) Vol. 189 Issue 5 Pg. 586-92 (Mar 01 2014) ISSN: 1535-4970 [Electronic] United States
• PMID: 24428575 (Publication Type: Clinical Trial, Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Breath Tests
• Bronchiectasis (diagnosis, diagnostic imaging, physiopathology)
• Feasibility Studies
• Female
• Forced Expiratory Volume
• Humans
• Lung (diagnostic imaging, physiopathology)
• Male
• Middle Aged
• Models, Statistical
• Quality of Life
• ROC Curve
• Regression Analysis
• Respiratory Function Tests
• Sensitivity and Specificity
• Severity of Illness Index
• Spirometry
• Surveys and Questionnaires
• Tomography, X-Ray Computed (methods)
• Young Adult