Blind spot in sepsis management – Tissue level changes in microcirculation

Abstract

AbstractIn sepsis cytokine-mediated inflammation, clotting cascade activation and glycocalyx shedding impair both function and structure of the microcirculation, compromising adequate tissue oxygenation/perfusion. Such mismatch results in “dysoxia”, an imbalance in mitochondrial respiration.Microvessel injuries can be grouped into four types: cytotoxic oedema, micro-vessel heterogeneity, sluggish/absent flow, and focal anaemia. Recognition of such diversity in microcirculatory pathology, alongside with the implementation of novel biomarkers might reveal previously unobserved heterogeneity in adults diagnosed with sepsis. Early identification of distinct subtypes may help not only to better stratify disease severity but may also provide explanation to the often seen insufficient/absent response to resuscitative treatment. Experimental evidence suggests that impaired microcirculatory flow may correlate with organ dysfunction and mortality. Therefore, reliable/reproducible diagnostic tools, that provide real-time information about the dynamic state of the microcirculation, might be practice changers in managing the critically ill.The sublingual mucosa and the nailfolds provide easy access to microcirculation via hand-held, point-of-care devices. Accessing these windows, clinicians may recognise, understand and potentially correct the underlying tissue oxygenation/perfusion mismatch. This new clinical information might facilitate an individualised approach vs protocolised care aiming to administer the right balance of intravenous fluids/vasopressors, time/dose auxiliary treatment modalities and, most importantly, might also guide determining the optimal duration of resuscitation to avoid/minimise harm and maximise benefits in sepsis management. However, before every-day clinical use of such point-of-care microcameras, validation studies are needed to establish not only feasibility but reliability and reproducibility as well.