Microcirculatory dysfunction and resuscitation: why, when, and how

Abstract

Cardiovascular resuscitation is a cornerstone of critical care practice. Experimental advances have increased our understanding of the role of the microcirculation in shock states and the development of multi-organ failure. Strategies that target the microcirculation in such conditions, while theoretically appealing, have not yet been shown to impact upon clinical outcomes. This review outlines the current understanding of microcirculatory dysfunction in septic, cardiogenic, and hypovolaemic shock and outlines available treatments and strategies with reference to their effects upon the microcirculation.

Clinical use of plasma lactate concentration. Part 2: Prognostic and diagnostic utility and the clinical management of hyperlactatemia

“…157 The ideal strategies to diagnose and treat microcirculatory and mitochondrial derangements have not been defined. Although not readily available for use in clinical practice, microcirculatory monitoring techniques such as sidestream microscopy are presently under investigation, [158][159][160] and therapies to improve microcirculatory flow such as dobutamine, nitrates, and calcium sensitizers are also being evaluated. 161,162 Research is also ongoing into interventions targeting mitochondrial dysfunction including cofactor supplementation, mitochondrial anti-oxidants, reactive oxygen species scavengers, and mitochondrial membrane stabilizers.…”

Septic shock resuscitation in the first hour

“…The associated impaired vascular smooth muscle tone, relative hypovolemia and a reduction in the FCD results in a heterogeneous combination of microcirculatory units lose their ability to regulate vascular tone and inappropriately constricted arterioles coexist with vasodilated units. These changes result in inefficient microcirculation resulting in an oxygen partial pressure (PO2) gap evidenced by the reduced capillary PO2, increased venous PO2 and impaired mitochondrial oxygen extraction (10,11).…”

Effects of volume resuscitation on the microcirculation in animal models of lipopolysaccharide sepsis: a systematic review

“…The aetiology of microcirculatory dysfunction seen during sepsis is multi-factorial, including increased blood viscosity, reduced red blood cell deformability [69], neutrophil activation [70] and impaired vascular auto-regulation [20], leading to inadequate oxygen delivery to tissues. The mechanical properties of red blood cells are altered by effects of endotoxin binding directly to the red blood cells [71].…”

“…This network together forms the largest organ system in the body [20]. Microcirculatory function of coupling the delivery of metabolic substrates to respiring tissues, relative to requirements, and the removal of metabolic products, has been shown to be the main prerequisite for adequate tissue oxygenation and organ function [17].…”