Microcirculatory effects of fluid therapy and dopamine, associated or not to fluid therapy, in endotoxemic hamsters

Protective microcirculatory and anti-inflammatory effects of heparin on endotoxemic hamsters

“…Several factors are related to the microcirculatory impairment observed after endotoxemia induction, such as systemic hypotension, vasoconstriction, stiffness of RBC, increased leukocyte-endothelium interactions, and platelet/fibrin clot formation. 5 Because differences in capillary perfusion between groups cannot be entirely explained by changes in arteriolar mean internal diameter or by macro-hemodynamic changes, we can speculate that anti-inflammatory and antithrombotic activities of both heparin and rhAPC may have been crucial to capillary perfusion differences observed between groups seeing that capillary obstruction by microthrombi and an increased presence of rolling and adherent leukocytes in venules may hamper adequate capillary flow. 2,21,22,23 Thus, reduction of microvascular platelet aggregation and leukocyte plug formation facilitates capillary blood flow, improving tissue perfusion and reducing organ failure.…”

“…Because endotoxemia is a known up-regulator of leukocyte-endothelial interactions and because increased leukocyte-endothelium interactions are related to microcirculatory impairment 5 , we have performed intravital fluorescence microscopy to study leukocyte kinetics. Leukocyte migration involves a step-wise process: first leukocytes roll along the vascular endothelium, then they firmly adhere and finally emigrate from the microcirculation to inflamed tissues.…”

“…3 As sepsis progresses, microcirculatory abnormalities ultimately result in tissue hypoxia, organ failure, and death. 4,5 Seeing that levels of antithrombotic factors are frequently very low in patients with severe sepsis and septic shock, it could be speculated that correction of those low levels could assist in reversal of the septic procoagulant state, attenuating microvascular perfusion deficits and improving patients' outcome. 6 In this way, numerous clinical trials have already examined the use of antithrombotic drugs such as recombinant human activated protein C (rhAPC), tissue factor pathway inhibitor, and antithrombin III in septic patients.…”

Milrinone Attenuates Arteriolar Vasoconstriction and Capillary Perfusion Deficits on Endotoxemic Hamsters

“…When FCD temporal evolution was considered, our study showed that only the full dose of milrinone (0.50 μg.kg -1 .min -1 ) was associated with significant attenuation of LPS-induced decrease of FCD. Several factors are related to the microcirculatory impairment observed after endotoxemia induction, such as vasoconstriction, increased leukocyte-endothelium interactions, and platelet/fibrin clot formation [ 4 ]. Since FCD differences between both milrinone groups cannot be explained by changes in arteriolar mean internal diameter, macro-hemodynamic changes, or anti-inflammatory effects, we may speculate that differences in antithrombotic activity between the two groups may have been crucial to the observed differences since capillary obstruction by microthrombi may hamper adequate capillary flow [ 29 , 30 ].…”

“…Sepsis is an infection-related systemic inflammatory syndrome with high incidence, morbidity, mortality, and cost to healthcare system [ 1 , 2 ]. In sepsis syndrome, the inflammatory response is associated with microthrombosis and microvascular vasoconstriction, leading to microcirculatory dysfunction, the critical first stage in sepsis progression towards tissue hypoxia, organ failure, and death [ 3 , 4 ]. Impaired microcirculatory perfusion occurs in patients with septic shock despite restoration of intravascular volume and/or normalization of blood pressure [ 5 ].…”