Analysis of the sublingual microvascular glycocalyx in critically ill patients - a prospective observational study

Objective: The endothelial glycocalyx (EG) plays a central role in the coupling functions of microcirculation and tissue metabolism. EG is particularly important in critically ill patients in whom it suffers damage. The aim of study was to describe the condition of EG in critically ill patients in dependence of the severity of the illness and the usage of various methods of organ support, using a non-invasive method assessment. Design: Monocentric, prospective, observational study. Setting: Intensive Care Unit (ICU) at a University Hospital. Materials and methods: Adult patients admitted to the ICU with anticipated length of stay of at least 7 days were enrolled. Demographic and clinical data were recorded together with sublingual microcirculation recordings for Perfused Boundary Region (PBR) analysis. Results: Total 40 patients were selected for the analysis. The median (IQR) baseline PBR was 1.97 mu m (1.75-2.12). There was no significant difference in PBR at different time points. PBR poorly correlated with the APACHE II and SOFA scores. PBR was shown as a poor predictor of septic shock or positive fluid balance. PBR was significantly higher in patients with insidious onset of critical illness (p = 0.0038) and in patients with renal replacement therapy (CRRT) (p = 0.007). Conclusion: The PBR parameter shows a high inter-individual variability and cannot be considered as a reliable method of assessment of EG damage in critically ill patients. PBR is not a suitable method for predicting clinical conditions such as sepsis or positive fluid balance. Higher PBR values were associated with the presence of septic shock, insidions onset of critical illness and CRRT.