Best practice & research. Clinical anaesthesiology
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Microvascular alterations are a hallmark of sepsis and play a crucial role in its pathophysiology. Such alterations are the result of overwhelming inflammation, which negatively affects all the components of the microcirculation. ⋯ Other therapeutic interventions are still being investigated. In this review, we discuss the pathophysiology of septic microcirculatory dysfunction and its implications for possible treatments.
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Best Pract Res Clin Anaesthesiol · Dec 2016
ReviewHaemodynamic coherence - The relevance of fluid therapy.
The ultimate goal of fluid therapy is to improve the oxygenation of cells by improving the cardiac output, thus improving microcirculation by optimizing macrocirculation. This haemodynamic coherence is often altered in patients with haemorrhagic shock and sepsis. The loss of haemodynamic coherence is associated with adverse outcomes. ⋯ Monitoring microcirculation and haemodynamic coherence may be an additional tool to predict the response to fluid administration. In addition, microcirculatory analysis may support the clinician in his decision to not administer fluids when microcirculatory blood flow is preserved. In future, the indication, guidance and termination of fluid therapy may be assessed by bedside microvascular analysis in combination with standard haemodynamic monitoring.
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Best Pract Res Clin Anaesthesiol · Dec 2016
ReviewRed blood cell transfusion and its effect on microvascular dysfunction in shock states.
Among critically ill patients, red blood cell (RBC) transfusion is often prescribed for anemia in the absence of active or recent bleeding. The failure of RBC transfusion to improve physiological parameters and clinical outcomes in this setting may be explained by current understanding of the relationship between the RBCs and the microcirculation. It is now evident that the circulating RBCs contribute to microcirculatory hypoxic vasodilation by regulated nitric oxide (NO)-dependent vasodilation, thereby facilitating delivery of oxygen to oxygen-deprived tissue. ⋯ In recent years, there has been a significant focus on the dysfunctional interaction between stored RBCs and the microcirculation, with emphasis on understanding the mechanisms that drive erythrocyte NO-mediated vasodilation. The development of technology that allows noninvasive observation of the microcirculation in humans has allowed for direct observation of the microcirculation immediately before and after RBC transfusion. The current understanding of RBC NO-mediated vasodilation and the results of direct observation of the microcirculation in the setting of RBC transfusion are reviewed.
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Best Pract Res Clin Anaesthesiol · Dec 2016
ReviewLactate levels and hemodynamic coherence in acute circulatory failure.
In this review, the relationship between changes in macrohemodynamics during the development and treatment of acute circulatory failure is discussed in the context of coherence with microcirculation and changes in lactate. In models of circulatory failure, coherence between changes in macrocirculatory and microcirculatory perfusion and coherence with subsequent changes in lactate levels are more or less preserved. ⋯ Resuscitation should therefore aim at adequate tissue perfusion where systemic hemodynamics, microcirculatory perfusion parameters, and lactate levels should be used in their relevant context. This results in treating the individual patient as an n = 1 experiment.
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Best Pract Res Clin Anaesthesiol · Sep 2016
ReviewThe role of transesophageal echocardiography in aortic surgery.
Aortic disease, when left untreated, is still associated with major morbidity and mortality. Aortic dissection and aortic aneurysm are the main reasons for performing aortic surgery procedures in the adult. Imaging techniques such as computed tomography and magnetic resonance imaging play a key role in the preoperative evaluation. ⋯ Especially during endovascular aortic repair, TEE is more sensitive than other imaging modalities in diagnosing complications such as graft endoleaks. Newer echocardiographic techniques such as three-dimensional (3D) TEE and contrast-enhanced TEE are emerging and seem to have a valuable role especially in aortic dissection repair and endovascular aortic stent procedures. In the absence of contraindications, TEE should generally be performed during aortic surgery and endovascular aortic procedures.