Redistribution of cardiac output during hemorrhagic shock in sheep

Abstract

Minor blood flow redistribution between supra-aortic and descending aortic territories was seen only following blood restitution but not during hemorrhage in these anesthetized ewes. This observation supports the robustness of the assumption of constant flow proportion used by the esophageal Doppler monitor to calculate systemic stroke volume from descending aortic flow measurements.

Fluid Resuscitation Does Not Improve Renal Oxygenation during Hemorrhagic Shock in Rats

“…Although using a different animal model, the authors have shown that only minor blood flow redistribution exists between supra-aortic and descending aortic territories during hemorrhage. 52 Finally, cytokine levels correlate with the severity of hemorrhagic shock 53 and have been reported to be associated with a poor prognosis in patients with acute kidney injury; further, IL-6 has been linked to the development of remote organ injury in hemorrhagic shock. 54,55 We are aware that the rather small sample size of the groups might have introduced a lack of power in the statistical analysis and prevented us from drawing a conclusion regarding the effect of fluid resuscitation strategies on cytokine levels.…”

Evaluation of transesophageal echo-Doppler ultrasonography for the measurement of aortic blood flow in anesthetized cats

“…Moreover, the proportion of CO reaching the descending aorta depends on the actual CO and is expected to be higher at a high CO than at a low CO because cardiac and cerebral blood flow are better preserved than the blood flow to other organs during low CO states. 11,24,25 Overall analysis of the data pairs obtained in the study revealed a high correlation (r = 0.884) between results for the thermodilution and TED techniques. Comparison of the TED technique with the traditional thermodilution method for measuring CO in humans has revealed variable results that range from poor 17 to strong 11,15,18 correlations.…”

Thoracic Aortic Pulsatility Decreases During Hypovolemic Shock:Implications for Stent-Graft Sizing

“…As the hemorrhage advances, the heart rate increases but the stroke volume and cardiac output decrease. 21–23 Experimental canine models have demonstrated a decrease of around 40% in stroke volume during hemorrhagic shock. 22,23 Since the aortic distention during the cardiac cycle is primarily the result of ventricular contraction and the subsequent stroke volume pumped into the aorta, the pulsatile aortic distention will decrease as the stroke volume decreases.…”