Interactions between respiration and systemic hemodynamics. Part II: practical implications in critical care

Intensive Care Med. 2009 Feb;35(2):198-205. doi: 10.1007/s00134-008-1298-y. Epub 2008 Sep 30.


In Part I of this review, we have covered basic concepts regarding cardiorespiratory interactions. Here, we put this theoretical framework to practical use. We describe mechanisms underlying Kussmaul's sign and pulsus paradoxus. We review the literature on the use of respiratory variations of blood pressure to evaluate volume status. We show the possibilities of attaining the latter aim by investigating with ultrasonography how the geometry of great veins fluctuates with respiration. We provide a Guytonian analysis of the effects of PEEP on cardiac output. We terminate with some remarks on the potential of positive pressure breathing to induce acute cor pulmonale, and on the cardiovascular mechanisms that at times may underly the failure to wean a patient from the ventilator.

Publication types

  • Review

MeSH terms

  • Blood Pressure / physiology*
  • Cardiac Output / physiology
  • Coronary Circulation / physiology*
  • Critical Care*
  • Hemodynamics / physiology*
  • Humans
  • Hypertension, Pulmonary / etiology
  • Positive-Pressure Respiration / methods
  • Pulmonary Heart Disease / complications
  • Pulmonary Heart Disease / therapy
  • Pulse
  • Respiration
  • Respiration, Artificial
  • Respiratory Insufficiency / etiology
  • Respiratory Insufficiency / therapy
  • Venous Pressure / physiology
  • Ventricular Dysfunction, Left / complications