Science‐in‐brief: The role of the glycocalyx in critically ill patients with reference to the horse

Abstract

Science-in-brief: The role of the glycocalyx in critically ill patients with reference to the horse The glycocalyx is a gel-like layer covering the luminal surface of vascular endothelial cells. It is comprised of membrane-attached proteoglycans, glycosaminoglycan chains and glycoproteins synthesised by the endothelial cells and adherent plasma proteins. The glycocalyx is essential for maintaining homeostasis in the vasculature. 1 In the healthy state, the glycocalyx regulates vascular permeability, provides anti-coagulant and anti-adhesive effects on the surface of endothelial cells and can shield endothelial cells from oxidative stress. 1,2 Additionally, the glycocalyx senses fluid shear forces and transmits these forces to endothelial cells, initiating nitric oxide-mediated vasorelaxation. Considering these key functions, interest in the glycocalyx has significantly increased in the last decades and damage to this vital layer appears to influence progression and recovery in many disease processes.

Preoperative and intraoperative risk factors for post‐anaesthetic pulmonary oedema in horses

“…In severe sickness, the glycocalyx structure is damaged, increasing lung vascular permeability, which may contribute to PAPOE. The glycocalyx in horses is poorly investigated (Dunkel, 2020) and could not be assessed in our study; however, this should be considered as an accelerating factor to PAPOE and further studies.…”

“…Factors associated with PAPOE in univariable analysis also included HES administration and blood loss ( p = 0.03 and p = 0.042, respectively). Administration of HES increases the intravascular oncotic pressure in horses (Viljoen et al, 2014), therefore, is supposed to protect from lung oedema, assuming that the glycocalyx layer is functional (Dunkel, 2020). Acute blood loss leads to reduction in circulatory volume, stroke volume and systemic vascular pressure.…”

“…This is a dynamic layer of macromolecules at the luminal surface of vascular endothelium that is involved in fluid homeostasis and regulation (Collins et al, 2013). In healthy states, it serves as a barrier opposing vascular permeability through a negatively charged molecular meshwork by limiting trans‐vascular movement of molecules that are negatively charged, larger than 70‐kDa, or both (Dunkel, 2020). In severe sickness, the glycocalyx structure is damaged, increasing lung vascular permeability, which may contribute to PAPOE.…”