Evaluation of the Effect of Induced Endotoxemia on ROTEM S(®) and Platelet Parameters in Beagle Dogs Anaesthetized with Sevoflurane

SIMPLE SUMMARY: Bacterial infection can cause different bleeding or thrombotic disorders in addition to the well-known cardiovascular disorders in dogs. The understanding of the changes of the coagulation system associated with bacterial infection has improved. However, the knowledge of how therapeutic measures against cardiovascular effects might influence the coagulation system is still scarce. The better availability of point-of-care testing in clinics enables the repeated evaluation of coagulation status in clinical patients. This study evaluated the influence of artificially induced endotoxemia and the subsequent treatment with fluids and vasopressors at five timepoints with complete blood count, thrombo-aggregometry and -elastometry and d-dimer analysis in six dogs under sevoflurane anaesthesia. We found signs of hypocoagulability mainly caused by fast decreases in platelet counts. The partial recovery of all coagulation parameters may reflect a positive impact of therapeutic measures of the cardiovascular system on the coagulation status of endotoxemic dogs. ABSTRACT: Endotoxemia is thought to induce severe changes in coagulation status. In this study, blood samples from six beagle dogs receiving 1 mg/kg E. coli lipopolysaccharide (LPS) intravenously were analyzed to describe the concurrent changes in platelet count, platelet function assessed with impedance thromboaggregometry, thromboelastometry and d-dimers during artificially induced endotoxemia and its therapy with fluids and vasopressors at five timepoints (baseline, after LPS and 30 mL/kg Ringer’s acetate, during noradrenaline ± dexmedetomidine infusion, after a second fluid bolus and a second time after vasopressors). Results were analyzed for changes over time with the Friedman test, and statistical significance was set at p < 0.05. We found decreased platelet count and function and changes in all platelet-associated rotational thromboelastometry (ROTEM) variables indicating hypocoagulability, as well as increases in d-dimers indicating fibrinolysis within one hour of intravenous administration of LPS, with partial recovery of values after treatment and over time. The fast changes in platelet count, platelet function and ROTEM variables reflect the large impact of endotoxemia on the coagulation system and support repeated evaluation during the progress of endotoxemic diseases. The partial recovery of the variables after initiation of fluid and vasopressor therapy may reflect the positive impact of the currently suggested therapeutic interventions during septic shock in dogs.