Effects of Induced Endotoxaemia on Global Cardiovascular, Oxygenation and Haematologic Variables and the Integrity of the Endothelial Glycocalyx in the Horse.

Abstract

BACKGROUND: Endotoxaemia is a significant cause of morbidity and mortality in equids due to perfusion impairment and possible destruction of the glycocalyx. OBJECTIVES: To evaluate our hypothesis that endotoxaemia induces changes in global cardiovascular and haematologic parameters and compromises glycocalyx integrity, evidenced by an early rise in plasma shedding products. STUDY DESIGN: In vivo experiments METHODS: In a prospective, randomised, controlled experimental trial, endotoxaemia was induced with E. coli B55:O5 LPS 30&#xa0;ng kgover 30 min IV in six healthy adult horses ventilated with oxygen supplemented with isoflurane. Standard cardiovascular variables were recorded and calculated, and leucocyte counts, lactate, heparan sulphate and syndecan-1 concentration were determined at baseline (B) before endotoxin and at 0, 30, 60 and 120 min after endotoxin. Data were analysed using mixed models and adjusted by Tukey-Kramer (SAS Enterprise Guide Software 7.1). RESULTS: After endotoxin (120 min), a significant increase (p &#x2264; 0.05) in cardiac index (43 &#xb1; 9&#xa0;vs. 80 &#xb1; 15&#xa0;mL kgmin, p < 0.01), in oxygen delivery index (8 &#xb1; 3&#xa0;vs. 17 &#xb1; 4&#xa0;mL minkg, p <0.001), in pulse pressure variation (8 &#xb1; 3&#xa0;vs. 17 &#xb1; 4, p < 0.01) and in lactate (1.55 &#xb1; 0,9&#xa0;vs. 4.4 &#xb1; 0.52&#xa0;mmol L, p < 0.0001) occurred with a decrease in systemic vascular resistance index (247 &#xb1; 87&#xa0;vs. 83 &#xb1; 20 dynes s kg cm, p < 0.001), diastolic arterial blood pressure (69 &#xb1; 14&#xa0;vs. 38 &#xb1; 5&#xa0;mmHg; p < 0.001), and leucocyte counts (5.6 &#xb1; 1.3&#xa0;vs. 1.5 &#xb1; 0.3 G l, p < 0.0001). No changes in the glycocalyx degradation products could be found. CONCLUSION: Short-term experimental endotoxaemia under isoflurane induced anticipated cardiovascular changes but did not alter glycocalyx shedding products in this study.