S. Tejiram1,2, K. E. Brummel-Ziedins3, T. Orpheo3, L. T. Moffatt2, J. W. Shupp1,2 1MedStar Washington Hospital Center,The Burn Center, Department Of Surgery,Washington, DC, USA 2MedStar Health Research Institute,Washington, DC, USA 3University Of Vermont,Department Of Biochemistry, College Of Medicine,Colchester, VT, USA
Introduction: Current studies examining the presence of an acute burn induced coagulopathy remain discordant. These studies rely on limited clinical laboratory tests that provide only a snapshot of their coagulation profile at a given time. The use of whole blood provides better insight in vivo because all blood components interact during testing. Both thromboelastography (TEG) and thromboelastometry (ROTEM) provide on-site evaluation of clotting performance and the potency of in situ fibrinolysis utilizing various initiators. Understanding clot dynamics following acute burn injury could better identify the presence of coagulation defects, its pathophysiology, and potential management strategies. The aim of this work was to investigate the usefulness of pure extrinsic pathway initiators as an adjunct to identify coagulation defects versus a combined intrinsic/extrinsic pathway activator in a prospective cohort of acute burn injured patients.
Methods: A cohort of 28 burn injured patients who presented to a regional burn center from 2013 to 2016 were enrolled for prospective study. Whole blood collected from these patients at set intervals from admission to three weeks afterward underwent viscoelastic measurement by TEG and ROTEM. Data on patient demographics, injury characteristics, and clinical laboratory measures such as the international normalized ratio (INR) were also obtained. Initiators used in TEG were RapidTEG while EXTEM and in-house relipidated tissue factor (TF) reagent were used in ROTEM. Patients were stratified into early (≤ 72 hours) and late (> 72 hours) timepoints as well as moderate (10 – 20%) and severe (> 20%) total body surface area (TBSA) burn sizes for comparison purposes.
Results: In a majority of patients, the INR was normal within 24 hours of admission and for the study duration. In comparing early to late time points using EXTEM assays, patients in the moderate burn size group experienced significant increases in clot formation time (CFT), rate of clot formation (angle), and clot strength (MCF) over time (p < 0.05). For in-house TF assays, significant increases were also seen in MCF and fibrinolysis (LI30) over time. In-house TF assays additionally identified significant increases in CT, CFT, and angle in the severely burned cohort compared to the moderately burned cohort (p < 0.05). RapidTEG assays in turn identified significant increases in angle and maximum amplitude (MA) over time and between burn size groups (p < 0.05).
Conclusion: Dynamic changes in coagulation were identified in patients following acute burn injury by viscoelastic measurements. This study helps further characterize the complex coagulopathic response that follows burn injury and helps identify extrinsic pathway initiators as an additional adjunct that could be used to study the hemostatic response to burn. Further work will aim to fully characterize the scope of burn induced coagulopathy and its associated outcomes.