The microcirculation describes the smallest elements of the cardiovascular conducting system and is pivotal in the maintenance of homeostasis. Microcirculatory dysfunction is present early in the pathophysiology of sepsis, with the extent of microcirculatory derangement relating to disease severity and prognosis in ICU patients.
At present microcirculatory function is not routinely monitored at the bedside. This article describes the pathophysiology of microcirculatory derangements in sepsis, methods of its measurement and evidence to support their clinical use.
Sepsis and the microcirculation
Sepsis affects all elements of the microcirculation. It is associated with a decrease in capillary density and increased heterogeneity of perfusion caused by inappropriate vasodilatation and vasoconstriction, leading to decreased oxygen delivery, tissue hypoxia and organ dysfunction.2 Mechanisms of microcirculatory dysfunction in sepsis include arteriolar hyporesponsiveness and capillary dysfunction, leading to extravasation of fluid protein and neutrophils.
The importance of microcirculatory assessment in sepsis
Several studies have demonstrated that: (a) improvements in the microcirculatory function in sepsis after early resuscitation are associated with a decreased incidence of organ dysfunction7 and (b) persistent microcirculatory dysfunction after resuscitation is associated with worse outcomes.8,9 However, the microcirculation is difficult to monitor in practice and so current resuscitation goals rely on the monitoring and restoration of macro-haemodynamic values (such as systemic arterial pressure, cardiac output, heart rate), along with restoration of organ perfusion (inferred from normalization of serum lactate and ScVO2).10 Moreover, restoration of macro-haemodynamic variables such as arterial pressure, especially with vasoactive agents such as noradrenaline, does not guarantee improvements in microcirculatory flow; in fact, noradrenaline can inhibit microcirculatory function irrespective of the presence of hypotension.11
Microcirculatory derangement is common in patients with sepsis and cannot necessarily be predicted from macro-haemodynamic values. Improvement in macro-haemodynamic values in the critically ill does not imply improvement in microcirculatory flow and patients whose microcirculation fails to improve following resuscitation are at increased risk of mortality. Detection of microcirculatory dysfunction may aid diagnosis and risk stratification in patients with sepsis; restoration of the function of the microcirculation may be a useful therapeutic target for resuscitation but further data are needed.
HOW D’OXYVA CAN HELP?
D’OXYVA is the only fully noninvasive, completely painless over-the-skin microcirculatory solution that has been clinically tested to significantly improve microcirculation.
D’OXYVA works to prevent sepsis, and resulting septic shock, using life-restoring molecule carbon dioxide (CO₂) and gentle vapor dissolved across the skin in a fast, painless, handheld 5-minute application — performed either in a clinical setting or in the comfort and privacy of your own home.