Journal Article

Association of sublingual microcirculation parameters and endothelial glycocalyx dimensions in resuscitated sepsis

Seidel, Laura Mareen, Vink, Hans, Rovas, Alexandros, Pohlkötter, Timo, Pavenstädt, Hermann, Ertmer, Christian, Hessler, Michael, Kümpers, Philipp

2019

Overview

Background The endothelial glycocalyx (eGC) covers the luminal surface of the vascular endothelium and plays an important protective role in systemic inflammatory states and particularly in sepsis. Its breakdown leads to capillary leak and organ dysfunction. Moreover, sepsis-induced alterations of sublingual microcirculation are associated with a worse clinical outcome. The present study was performed to investigate the associations between eGC dimensions and established parameters of microcirculation dysfunction in sepsis. Methods This observational, prospective, cross-sectional study included 40 participants, of which 30 critically ill septic patients were recruited from intensive care units of a university hospital and 10 healthy volunteers served as controls. The established microcirculation parameters were obtained sublingually and analyzed according to the current recommendations. In addition, the perfused boundary region (PBR), an inverse parameter of the eGC dimensions, was measured sublingually, using novel data acquisition and analysis software (GlycoCheck™). Moreover, we exposed living endothelial cells to 5% serum from a subgroup of study participants, and the delta eGC breakdown, measured with atomic force microscopy (AFM), was correlated with the paired PBR values. Results In septic patients, sublingual microcirculation was impaired, as indicated by a reduced microvascular flow index (MFI) and a reduced proportion of perfused vessels (PPV) compared to those in healthy controls (MFI, 2.93 vs 2.74, p  = 0.002; PPV, 98.53 vs 92.58, p  = 0.0004). PBR values were significantly higher in septic patients compared to those in healthy controls, indicating damage of the eGC (2.04 vs 2.34, p  < 0.0001). The in vitro AFM data correlated exceptionally well with paired PBR values obtained at the bedside (rs = − 0.94, p  = 0.02). Both PBR values and microcirculation parameters correlated well with the markers of critical illness. Interestingly, no association was observed between the PBR values and established microcirculation parameters. Conclusion Our findings suggest that eGC damage can occur independently of microcirculatory impairment as measured by classical consensus parameters. Further studies in critically ill patients are needed to unravel the relationship of glycocalyx damage and microvascular impairment, as well as their prognostic and therapeutic importance in sepsis. Trial registration Retrospectively registered: Clinicaltrials.gov, NCT03960307

• Publisher: BioMed Central,BioMed Central Ltd,BMC
• Subject: Adult / Aged / Aged, 80 and over / Atomic force microscopy / Biomarkers - analysis / Biomarkers - metabolism / Care and treatment / Critical Care Medicine / Cross-Sectional Studies / Data collection / Diagnosis / Emergency Medicine / Endothelial Cells - drug effects / Endothelial Cells - metabolism / Endothelial Cells - physiology / Endothelial glycocalyx / Endothelium / Female / Glycocalyx - drug effects / Glycocalyx - metabolism / Glycocalyx - physiology / Health aspects / Humans / Infection / Intensive / Intravital microscopy / Male / Measurement / Medical examination / Medical research / Medicine / Medicine & Public Health / Microcirculation / Microcirculation - drug effects / Microcirculation - physiology / Microscopy / Middle Aged / Novels / PBR / Perfused boundary region / Prospective Studies / Resuscitation - adverse effects / Resuscitation - methods / Retrospective Studies / Sepsis / Sepsis - metabolism / Sepsis - physiopathology / Vascular endothelium