Lung ventilation and aerosol deposition in health and disease

In recent years, the laboratory has focused on the study of ventilation abnormalities and aerosol deposition in patients with lung disease. One project looked at the effect of mild-to-moderate obstructive lung disease on the fate of inhaled aerosol boluses. While aerosol deposition was unaffected by the presence of disease, other parameters such as aerosol bolus dispersion and mode shift showed higher sensitivity to alterations in airway flow patterns and to increased ventilation heterogeneity induced by lung disease. 

Another project focused on the distribution of ventilation in cystic fibrosis (CF) patients and how this distribution is affected by the presence of excess water in the lungs of these patients. Preliminary data show that combining measures of ventilation inhomogeneity using multiple breath washouts (MBW) with a measure of lung water density using MRI could provide new biomarkers of disease severity in CF patients.

Studies in healthy individuals have focused on linking aerosol deposition patterns measured by gamma scintigraphy to ventilation distribution measured by specific ventilation imaging (SVI) and also on the effect of posture on the distribution of deposited particles. 

Experimental approaches include:

  • Aerosol bolus inhalation
  • photometry
  • Gamma scintigraphy
  • Multiple breath washouts (MBW)
  • MRI and specific ventilation imaging (SVI)

Relevant publications

  • Sá, R.C., A.K. Asadi, R.J. Theilmann, S.R. Hopkins, G.K. Prisk, and C. Darquenne. Validating the distribution of specific ventilation in healthy humans measured using proton MR imaging. J. Appl. Physiol., 116:1048-1056, 2014 (PMC4035784).
  • Darquenne C., W.J. Lamm, J.M. Fine, R.A. Corley and R.W. Glenny. Total and regional deposition of inhaled aerosols in healthy supine subjects and subjects with mild-to-moderate COPD. J. Aerosol Sci, 99:27-39, 2016 (doi:10.1016/j.jaerosci.2016.01.019).
  • Sá, R.C., K.L. Zeman, W.D. Bennett, G.K. Prisk and C. Darquenne. Regional ventilation is the main determinant of alveolar deposition of coarse particles in the supine healthy human lung during tidal breathing. J. Aerosol Med. Pulm. Drug Delivery. 30:322-331, 2017 (DOI: 10.1089/jamp.2016.1336).
  • Theilmann, R.J., C. Darquenne, A.R. Elliott, B.A. Bailey and D.J. Conrad. Characterizing Lung Disease in Cystic Fibrosis with Magnetic Resonance Imaging and Airway Physiology. PLoS ONE, 11(6): e0157177, 2016 (doi:10.1371/journal.pone.0157177).

A full list of publications can be found on Chantal Darquenne's UCSD profile page