Age-dependent cardiopulmonary interaction during airway obstruction: a simulation model.
Inspiratory fall in arterial blood pressure (Pa) during airway obstruction was ascribed to ventricular interdependence, afterload, and transmission of intrathoracic pressure swings. We have shown this effect significantly reduced in the elderly, but the underlying reasons remain unclear. Here we compare the results of inspiratory loading in young and older subjects with a mathematical model that simulated beat-by-beat fluctuations in cardiopulmonary variables. By increasing arterial and left ventricular elastance parameters in the older group, simulations strongly correlated with the experimental Pa and identified a linear increase of left ventricular transmural pressures with negative intrathoracic pressure that was nearly 38% larger than that in the younger group. The apparent perfusion preservation by less Pa decline with obstruction in the elderly could be misleading, since it reflects an increased afterload and diastolic dysfunction.
Goldman
Ernesto
E
The Ohio State Univ. Medical Center, Dept. of Anesthesiology, 410 W. 10 Ave., Columbus, OH 43210, USA. ernesto.goldman@osumc.edu
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D000402:Airway Obstruction / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology; D002319:Cardiovascular System / Q000503:physiopathology*; D045853:Exhalation / Q000502:physiology; D006801:Humans; D001239:Inhalation / Q000502:physiology; D008168:Lung / Q000503:physiopathology*; D008962:Models, Theoretical; D013318:Stroke Volume / Q000502:physiology; D016277:Ventricular Function, Left / Q000502:physiology