Differential alterations in microvascular perfusion in various organs during early and late sepsis

Abstract

Although cellular dysfunction occurs very early in sepsis, it remains controversial whether this is solely due to a decrease in tissue perfusion. Recent studies have indicated that while active hepatocellular function was depressed, hepatic surface microvascular blood flow (MBF) increased in early sepsis but decreased in late sepsis as produced by cecal ligation and puncture (CLP). However, it is not known whether microvascular hyperperfusion in early sepsis and microvascular hypoperfusion in late sepsis are common events in other organs under such conditions. To study this, rats were subjected to sepsis by CLP, after which these and the corresponding shams received 3 ml/100 g body wt normal saline. Microvascular perfusion and MBF in various tissues were assessed by colloidal carbon infusion and laser-Doppler flowmetry, respectively, at 5 h (i.e., early sepsis) or 20 h (late sepsis) after CLP or sham operation. Carbon-perfused areas were quantitated by an Optomax image analyzer. The results indicate that the carbon-perfused areas and MBF in the liver, renal cortex, spleen, and small intestinal serosa (only MBF) increased significantly 5 h after CLP. In late sepsis, however, the carbon-perfused areas and MBF were found to be significantly decreased. A highly linear relationship was observed between the changes of carbon-perfused areas and MBF during sepsis in the tested organs. Thus the microvascular responses in the fluid-resuscitated sepsis model are characterized by hyperperfusion in the early stage and hypoperfusion in the late stage of sepsis in the tested tissues. The cellular dysfunctions observed during the early stage of sepsis are, therefore, not due to any reduction in tissue perfusion.

Control of Local Bacterial Soft Tissue Contamination by Adequate Microvascular Response is Critically Dependent on the Extent of Bacterial Challenge

“…In both groups, venular dilation was observed, though that of the 2 ϫ 10 7 -group was far more pronounced. These observations, again the most likely explanation being the difference in amount of pathologic agent released, are conform to observations made for endotoxemia [31].…”

“…We could observe two opposing reactions depending on the degree of bacterial contamination. Controversy remains as to whether initial arterial reaction is one of vasoconstriction or rather vasodilation [31,32]. In line with Zweifach et al [33], a dose-dependent increase (2 ϫ 10 5 -group) and decrease (2 ϫ 10 7 -group) in vascular reactivity to catecholamines, culminating in a complete absence of reactivity, must be postulated.…”

Combined Administration of Human Ghrelin and Human Growth Hormone Attenuates Organ Injury and Improves Survival in Aged Septic Rats

“…Cardiovascular dysfunction, specifically a reduction in cardiac contractility, is often observed in severe sepsis (33). LVDP and the maximal rate of ventricular pressure development (+dP/dt max ) were significantly decreased by 83.1% and 81.2%, respectively, compared with sham rats.…”

Gut Glutamine Metabolism at Different Stages of Sepsis in Rats

“…[1][2][3][4] The pathophysiological responses to sepsis usually include an initial hyperdynamic phase (early sepsis) followed by a hypodynamic phase (late sepsis). [5][6][7] The intestinal tract plays an important physiologic and metabolic role during the catabolic state. Glutamine is the principal fuel used by the gut 8,9 and may be an essential component for the maintenance of gut structure and function.…”