Relationships between the lung clearance index and conductive and acinar ventilation heterogeneity.

M. Paiva, Daniël Schuermans, S. Hanon, Walter Vincken, A. Van Muylem, Sylvia Verbanck

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

Verbanck S, Paiva M, Schuermans D, Hanon S, Vincken W, Van Muylem A. Relationships between the lung clearance index and conductive and acinar ventilation heterogeneity. J Appl Physiol 112: 782-790, 2012. First published December 8, 2011; doi:10.1152/japplphysiol.01221.2011.-The lung clearance index (LCI) derived from a multiple breath washout test has regained considerable popularity in recent years, alternatively being promoted as an early detection tool or a marker of small airways function. In this study, we systematically investigated the link between LCI and indexes of acinar and conductive airways ventilation heterogeneity (Sacin, Scond) to assess potential contributions from both lung zones. Relationships were examined in 55 normal subjects after provocation, where only Scond is known to be markedly increased, and in 55 asthma patients after bronchodilation, in whom both Scond and Sacin ranged between normal and abnormal. LCI was correlated to Scond in both groups (R = 0.37-0.43; P <0.01 for both); in the asthma group, LCI was also tightly correlated to Sacin (R = 0.70; P <0.001). Potential mechanisms operational at various levels of the bronchial tree were identified by considering washout curvilinearity in addition to LCI to distinguish specific ventilation and dead space effects (also illustrated by simple 2-compartment model simulations). Although the asthma data clearly demonstrate that LCI can reflect very peripheral ventilation heterogeneities, the normal provocation data also convincingly show that LCI increases may be the exclusive result of far more proximal ventilation heterogeneities. Because LCI potentially includes heterogeneities at all length scales, it is suggested that ventilation imaging in combination with LCI measurement at the mouth could identify the scale of relevant ventilation heterogeneities. In the meantime, interpretations of LCI results in the clinic based on washout curves collected at the mouth should be handled with caution.
Original languageEnglish
Pages (from-to)782-790
Number of pages9
JournalJ Appl Physiol
Volume112
Issue numberMarch
Publication statusPublished - 2012

Keywords

  • Dead space
  • specific ventilation
  • multiple breath washout
  • Cystic-fibrosis

Fingerprint Dive into the research topics of 'Relationships between the lung clearance index and conductive and acinar ventilation heterogeneity.'. Together they form a unique fingerprint.

Cite this