Nonreversible conductive airway ventilation heterogeneity in mild asthma

J Appl Physiol (1985). 2003 Apr;94(4):1380-6. doi: 10.1152/japplphysiol.00588.2002. Epub 2002 Dec 6.


A multiple-breath washout technique was used to assess residual ventilation heterogeneity in the conductive and acinar lung zones of asthmatic patients after maximal beta(2)-agonist reversibility. Reversibility was assessed in 13 patients on two separate visits corresponding to a different baseline condition in terms of forced expiratory volume in 1 s [FEV(1); average FEV(1) over 2 visits: 92 +/- 21% of predicted (SE)]. On the visit corresponding to each patient's best baseline, 400 micro g salbutamol led to normal acinar ventilation heterogeneity, normal FEV(1), and normal peak expiratory flow; i.e., none was significantly different from that obtained in 13 matched controls. By contrast, conductive ventilation heterogeneity and forced expiratory flow after exhalation of 75% forced vital capacity remained significantly different from controls (P < or = 0.005 on both indexes). In addition, the degree of postdilation conductive ventilation heterogeneity was similar to what was previously obtained in asthmatic individuals with a 19% lower baseline FEV(1) and twofold larger acinar ventilation heterogeneity (Verbanck S, Schuermans D, Noppen M, Van Muylem A, Paiva M, and Vincken W. Am J Respir Crit Care Med 159: 1545-1550, 1999). We conclude that, even in the mildest forms of asthma, the most consistent pattern of non-beta(2)-agonist-reversible ventilatory heterogeneity is in the conductive lung zone, most probably in the small conductive airways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenergic beta-Agonists / therapeutic use
  • Adult
  • Albuterol / therapeutic use
  • Asthma / drug therapy
  • Asthma / physiopathology*
  • Bronchodilator Agents / therapeutic use
  • Case-Control Studies
  • Female
  • Forced Expiratory Volume / drug effects
  • Humans
  • Male
  • Middle Aged
  • Peak Expiratory Flow Rate / drug effects
  • Respiration* / drug effects
  • Severity of Illness Index
  • Vital Capacity / drug effects


  • Adrenergic beta-Agonists
  • Bronchodilator Agents
  • Albuterol