Keynote Message

The endothelial glycocalyx (EG) is a carbohydrate-rich scaffold of proteoglycans and glycosaminoglycans on the luminal surface of vascular endothelial cells. It maintains barrier function, prevents cellular adhesion by 'hiding' glycoproteins, and contains anticoagulants to maintain an anticoagulant phenotype. It is likely that shedding of the EG is one of the first steps in systemic inflammation and activation of coagulation, which then allows interactions between endothelial cells and circulating leucocytes and platelets. Systemic inflammatory diseases and various medical interventions, including IV fluid therapy, may damage the EG, compromising its function. Recently, it has been shown that fluid movement out of the vascular space is heavily influenced by the integrity of the EG rather than simple pressure dynamics (Starling's forces) and that damage to the EG promotes extravasation of fluid. This may be the preceding step to interstitial edema and organ compromise in critically ill patients. This lecture will review our understanding of the microcirculation and EG and make suggestions as to how this knowledge can be translated into our clinical practice.

Key References

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3.  Myburgh JA, Mythen MG. Resuscitation fluids. N Engl J Med. 2013;369:1243–1251. DOI: 10.1056/NEJMra1208627.

4.  Pries AR, Secomb TW, Jacobs H, et al. Microvascular blood flow resistance: role of endothelial surface layer. Am J Physiol. 1997;273:H2272–H9.

5.  Weinbaum S, Tarbell JM, Damiano ER. The structure and function of the endothelial glycocalyx layer. Annu Rev Biomed Eng. 2007;9:121–67. DOI: 10.1146/annurev.bioeng.9.060906.151959.