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Effects of cystic fibrosis lung disease on gas mixing indices derived from alveolar slope analysis

Research output: Contribution to journalArticlepeer-review

Original languageEnglish
Pages (from-to)197-203
Number of pages7
JournalRespiratory Physiology & Neurobiology
Issue number3
Publication statusPublished - 31 Aug 2008


S-cond and S-acin are derived from analysis of concentration-normalized phase III slopes (Sn-III) of a multiple breath inert gas washout. Studies in healthy and COPD subjects suggest these reflect ventilation heterogeneity in conducting and acinar airway zones respectively, but similar studies in cystic fibrosis (CF) are lacking. S-cond, S-acin and lungclearance index(LCI, a measure of overall gas mixing efficiency)were measured in 22 adults and 18 children with CF and 17 adult and 29 child controls. Plethysmography and gas transfer measurements were performed in adults, and spirometry in all subjects. S-cond was elevated in almost all CF patients, including children with mild disease and normal LCI. However, S-cond did not correlate with other measurements and appeared to reach a maximum; further increase in ventilation heterogeneity being restricted to S-acin. The nature and/or severity of CF lung disease may invalidate assumptions underlying the ability to separate phase III slope analysis of ventilation heterogeneity into proximal and peripheral components, and LCI may be a better indicator of gas mixing in this population. (c) 2008 Elsevier B.V. All rights reserved.

    Research areas

  • Adolescent, Adult, Age Factors, Child, Child, Preschool, Cystic Fibrosis, Female, Forced Expiratory Volume, Humans, Lung, Male, Middle Aged, Plethysmography, Pulmonary Ventilation, Respiration, Respiratory Function Tests, Young Adult

ID: 3422886