Comparison of mathematical and mechanical models of pressure-controlled ventilation

W. C. Burke, P. S. Crooke, T. W. Marcy, A. B. Adams, J. J. Marini

Research output: Contribution to journalArticle

22 Scopus citations

Abstract

Recent evidence that volume-cycled mechanical ventilation may itself produce lung injury has focused clinical attention on the pressure waveform applied to the respiratory system. There has been an increasing use of pressure-controlled ventilation (PCV), because it limits peak cycling pressure and provides a decelerating flow profile that may improve gas exchange. In this mode, however, the relationships are of machine adjustments to ventilation and alveolar pressure are not straightforward. Consequently, setting selection remains largely an empirical process. In previous work, we developed a biexponential model of PCV that provides a conceptual framework for understanding these interactions (J. Appl. Physiol. 67: 1081-1092, 1989). We tested the validity of this mathematical model in a single-compartment analogue of the respiratory system across wide ranges of clinician-set variables (frequency, duty cycle, applied pressure) and impedance conditions (inspiratory and expiratory resistance and system compliance). Our data confirm the quantitative validity of the proposed model when approximately rectilinear waves of pressure are applied and appropriate values for impedance are utilized. Despite a fixed-circuit configuration, however, resistance proved to be a function of each clinician-set variable, requiring remeasurement of system impedance as adjustments in these variables were made. With further modification, this model may provide a practical as well as a conceptual basis for understanding minute ventilation and alveolar pressure fluctuations during PCV in the clinical setting.

Original languageEnglish (US)
Pages (from-to)922-933
Number of pages12
JournalJournal of applied physiology
Volume74
Issue number2
DOIs
StatePublished - 1993

Keywords

  • dynamic hyperinflation
  • exponential kinetics
  • mathematical modeling
  • mechanical ventilation

Fingerprint Dive into the research topics of 'Comparison of mathematical and mechanical models of pressure-controlled ventilation'. Together they form a unique fingerprint.

  • Cite this