Effect of whole blood viscosity and red cell mass on canine thromboelastographic tracings

Bibliographic Details
Main Author: Brooks, Aimee C.
Language:English
Published: The Ohio State University / OhioLINK 2014
Subjects:
TEG
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=osu1397244092
id ndltd-OhioLink-oai-etd.ohiolink.edu-osu1397244092
record_format oai_dc
spelling ndltd-OhioLink-oai-etd.ohiolink.edu-osu13972440922021-08-03T06:23:49Z Effect of whole blood viscosity and red cell mass on canine thromboelastographic tracings Brooks, Aimee C. Veterinary Services Medicine Health Sciences Canine hematocrit thromboelastography TEG anemia transfusion alginate carboxymethylcellulose viscosity red blood cell Abnormalities in hemostasis can result in life-threatening bleeding or thrombotic disorders. Whole blood viscoelastic methodologies including thromboelastography (TEG) have become increasingly popular in human and veterinary research and clinical medicine as a means of assessing coagulation. However, the properties of blood that influence these methodologies must be understood to accurately interpret the results, especially when in vitro findings do not match what is expected in vivo.It is well established that the hematocrit (Hct) of a sample influences the TEG tracing. While, clinically, anemia has been shown to result in an increased risk of bleeding, anemic TEG tracings typically have a hypercoagulable appearance. The opposite is also seen, as TEG tracings of samples with high Hct appear hypocoagulable. The reason for this effect of Hct on TEG tracings is unknown. However, as Hct is the main determinant of whole blood viscosity, it is possible the influence of red blood cells on the TEG is truly the effect of viscosity. In order to elucidate this difference, whole blood viscosity must be manipulated separately from Hct. We hypothesized that the effect of Hct on TEG tracings may be due to a mechanical bias of the methodology due to the effect of Hct on blood viscosity, rather than the red blood cells themselves.To test this hypothesis, three experiments were performed. The first used alginate (ALG) to normalize blood viscosity independent of red cell mass at varying hematocrits (45%, 20%, and 10%) and compared to control samples diluted in saline. The second experiment had a similar design, but used a different agent, carboxymethylcellulose (CMC) to modify viscosity at Hcts of 20% and 10% compared to saline-diluted controls. Finally, TEG tracings and whole blood viscosity of naturally anemic dogs were compared immediately before and after red blood cell transfusion.These three experiments demonstrate that increasing the whole blood viscosity of a sample does make TEG tracings appear less hypercoagulable than anemic saline controls, independent of Hct. However, this effect appears to be relatively small, and the Hct has additional effects shifting the TEG tracing towards decreased hypercoagulability, independent of viscosity. The influence of the agent used to alter viscosity demonstrates that ALG may have additional properties that alter coagulation that have not been previously reported. To rule out an artifact of calcium binding, we demonstrate that the effect of CMC-altered viscosity on TEG tracings is preserved even with the addition of extra calcium. Finally, increasing Hct with RBC transfusion in clinically anemic dogs correlates with mildly decreased MA and G TEG values and increased whole blood viscosity. However, these alterations towards decreased hypercoagulability are relatively small compared to the global coagulation status of the animal. Overall, this data indicates that whole blood viscosity does have a small impact on TEG tracings independent of Hct, the effect of RBC mass on TEG tracings is greater than what can be explained by the impact of viscosity alone, and that these changes are relatively small in dogs with clinically significant anemia requiring red blood cell transfusion. 2014-08-28 English text The Ohio State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=osu1397244092 http://rave.ohiolink.edu/etdc/view?acc_num=osu1397244092 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Veterinary Services
Medicine
Health Sciences
Canine
hematocrit
thromboelastography
TEG
anemia
transfusion
alginate
carboxymethylcellulose
viscosity
red blood cell
spellingShingle Veterinary Services
Medicine
Health Sciences
Canine
hematocrit
thromboelastography
TEG
anemia
transfusion
alginate
carboxymethylcellulose
viscosity
red blood cell
Brooks, Aimee C.
Effect of whole blood viscosity and red cell mass on canine thromboelastographic tracings
author Brooks, Aimee C.
author_facet Brooks, Aimee C.
author_sort Brooks, Aimee C.
title Effect of whole blood viscosity and red cell mass on canine thromboelastographic tracings
title_short Effect of whole blood viscosity and red cell mass on canine thromboelastographic tracings
title_full Effect of whole blood viscosity and red cell mass on canine thromboelastographic tracings
title_fullStr Effect of whole blood viscosity and red cell mass on canine thromboelastographic tracings
title_full_unstemmed Effect of whole blood viscosity and red cell mass on canine thromboelastographic tracings
title_sort effect of whole blood viscosity and red cell mass on canine thromboelastographic tracings
publisher The Ohio State University / OhioLINK
publishDate 2014
url http://rave.ohiolink.edu/etdc/view?acc_num=osu1397244092
work_keys_str_mv AT brooksaimeec effectofwholebloodviscosityandredcellmassoncaninethromboelastographictracings
_version_ 1719435975706279936