Journal of Applied Physiology, Vol 63, Issue 2 564-570, Copyright © 1987 by American Physiological Society
Contribution of cardiogenic oscillations to gas exchange in constant-flow ventilation
I. J. Cybulsky, J. G. Abel, A. S. Menon, T. A. Salerno, S. V. Lichtenstein and A. S. Slutsky
Institute of Medical Science, Mount Sinai Hospital Research Institute, University of Toronto, Ontario, Canada.
The contribution of cardiogenic oscillations to gas exchange during
constant-flow ventilation was examined in 11 dogs. With the use of two
variations of cardiopulmonary bypass to maintain the systemic and pulmonary
circulation, the influence of cardiogenic oscillations was removed by
arresting the heart. Cardiac arrest by ventricular fibrillation was
associated with a mean decrease in alveolar ventilation of 43% in five dogs
on right and left heart bypass. However, successful defibrillation and
return of the prearrest level of alveolar ventilation could not be
achieved; thus we studied six dogs on left heart bypass. Alveolar
ventilation decreased an average of 37% with cardiac arrest, and
defibrillation resulted in a return of alveolar ventilation to 81% of the
prearrest value. These results are consistent with previous predictions
that cardiogenic oscillations are an important mechanism of gas transport
during constant-flow ventilation.
