Amplitude dependency of regional chest wall resistance and elastance at normal breathing frequencies

G. M. Barnas, C. F. Mackenzie, M. Skacel, Steven C Hempleman, K. M. Wicke, C. M. Skacel, S. H. Loring

Research output: Contribution to journalArticle

13 Scopus citations

Abstract

Current methods for measurement of chest wall properties assume that resistance (R) and elastance (E) are independent of the volume breathed. In six healthy subjects relaxed at functional residual capacity, we measured total and regional R and E of the chest wall within the range of normal breathing frequencies (0.2 to 0.6 Hz) and tidal volumes (250 to 750 ml), using volume forcing at the mouth as previously described. With these methods, esophageal and gastric pressures are compared with surface displacements measured with inductance plethysmographic belts to calculate R and E of rib cage and diaphragm-abdomen 'pathways'. Rib cage R and E were 25 to 30% higher than that of the total chest wall at each frequency and volume, whereas diaphragm-abdomen R and E were at least five times higher. R of the chest wall and each of the pathways decreased by about 70% with increasing frequency and by about 30% with increasing tidal volume. E of the chest wall and each of the pathways also decreased by about 30% with increasing tidal volume but was independent of frequency in this range. These results are consistent with nonlinear, viscoplastic models presented elsewhere. We conclude that: (1) despite the great structural differences between the rib cage and diaphragm-abdomen, each exhibits nonlinear behavior similar to that of the total chest wall; (2) chest wall R and E depend importantly on frequency and tidal volume.

Original languageEnglish (US)
Pages (from-to)25-30
Number of pages6
JournalAmerican Review of Respiratory Disease
Volume140
Issue number1
StatePublished - 1989
Externally publishedYes

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ASJC Scopus subject areas

  • Pulmonary and Respiratory Medicine

Cite this

Barnas, G. M., Mackenzie, C. F., Skacel, M., Hempleman, S. C., Wicke, K. M., Skacel, C. M., & Loring, S. H. (1989). Amplitude dependency of regional chest wall resistance and elastance at normal breathing frequencies. American Review of Respiratory Disease, 140(1), 25-30.