| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS | REGISTER |
|
|
|
|
|||||||||||||
|
|
|||||||||||||||
ORIGINAL ARTICLE |
1 Division for Clinical Sciences, Institute for Child Health Research, University of Western Australia
2 Centre for Child Health Research, University of Western Australia
3 Department of Medical Informatics and Engineering, University of Szeged, Hungary
4 Respiratory Medicine, University Children's Hospital, Zurich, Switzerland
Correspondence to:
Correspondence to:
Dr G L Hall, Respiratory Medicine, Princess Margaret Hospital for Children, GPO Box D184, Perth, 6840, Australia;
graham{at}ichr.uwa.edu.au
Background: In infants the impedance of the nasal pathways (Zn) is a significant proportion of the total respiratory impedance (Zrs).
Methods: In 11 infants Zrs was partitioned into Zn and lower respiratory system impedance (Zlrs) using a nasal catheter. A low frequency oscillatory signal (0.5–20 Hz) was applied during a pause in breathing to obtain the impedance spectra. A model of the respiratory system containing an airway and tissue compartment was then fitted to Zrs and Zlrs. The airway compartment consisted of a frequency independent resistance (R) and inertance (I), while the tissue compartment was described by coefficients of tissue damping (G) and elastance (H).
Results: Zrs could be reliably partitioned into Zn and Zlrs. The nasal pathway acted as a purely resistive-inertive impedance and contributed approximately half of the airway resistance (mean (SE) 44.6 (4.9)%) and most of the respiratory system inertance (71.7 (3.5)%).
Conclusion: In studies investigating changes in airway resistance in nasally breathing infants, the separation of nasal and lower respiratory system mechanics will increase the sensitivity of the tests.
Keywords: nasal resistance; respiratory impedance; infant lung function
Abbreviations: G, tissue damping; H, tissue elastance; I, inertance; Rn, nasal resistance; Rrs, resistance of the respiratory system; TGV, thoracic gas volume; Xn, nasal reactance; Xrs, reactance of the respiratory system; Zn, impedance of the nasal pathways; Zrs, total respiratory impedance; Zlrs, impedance of the lower respiratory system
This article has been cited by other articles:
|
|
 |
|
  E. Oostveen, D. MacLeod, H. Lorino, R. Farre, Z. Hantos, K. Desager, and F. Marchal The forced oscillation technique in clinical practice: methodology, recommendations and future developments Eur. Respir. J., December 1, 2003; 22(6): 1026 - 1041. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS | REGISTER |
