| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
* From the Department of Anesthesia, Toronto General Hospital, University Health Network; and the
Department of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada.
Address correspondence to: Dr. Marcin Wasowicz, Department of Anesthesia, Toronto General Hospital, 200 Elizabeth St., EN3-424, Toronto, Ontario M5G 2C4, Canada. Phone: 416-340-4800, ext. 3350; Fax: 416-340-3698; E-mail: marcin.wasowicz{at}uhn.on.ca
Purpose: Thromboelastography (TEG) evaluates the visco-elastic properties of whole blood to assess clot formation and hemostasis. When blood cannot be analyzed immediately, it is stored in citrated tubes to be analyzed after recalcification. In this study, we evaluated the results of TEG analysis performed on citrated blood and compared these results to values obtained from activated (kaolin and tissue factor) and non activated, fresh blood samples, obtained at various time intervals (one, two, and three hours).
Methods: Four blood samples were collected from each of ten healthy volunteers. The following TEG analyses were performed on each sample: reaction time (r), k time (k), alpha angle (
), and maximum amplitude (MA). Studies were done using fresh, non citrated blood, obtained within five minutes of collection, and using citrated blood, one, two, and three hours after collection. Samples were analyzed, with and without activation, using kaolin and tissue factor.
Results: Tissue factor activated and non activated, citrated samples had shorter r and k times (P = 0.03, P = 0.008, P < 0.0001, and P < 0.0001, respectively) and higher alpha angle and MA values (P < 0.0001, P < 0.0001, P = 0.79, and P = 0.03, respectively) compared to fresh, non citrated samples. These findings were consistent with a hypercoagulable state. Conversely, citrated samples, activated with kaolin, yielded results similar to those obtained from fresh, non citrated samples. The TEG measurements were similar among citrated samples stored from one to three hours.
Conclusions: Our results demonstrate that TEG measures, performed on citrated blood samples, yield results that are consistent with a hyperocoagulable state. Using kaolin to activate citrated samples, on the other hand, yields results similar to those obtained from non citrated, fresh blood samples.
1 Mallett SV, Cox DJ. Thrombelastography. Br J Anaesth 1992; 69: 307–13.
2 Kang YG, Martin DJ, Marquez J, et al. Intraoperative changes in blood coagulation and thrombelastographic monitoring in liver transplantation. Anesth Analg 1985; 64: 888–96.
3 Spiess BD, Gillies BS, Chandler W, Verrier E. Changes in transfusion therapy and reexploration rate after institution of a blood management program in cardiac surgical patients. J Cardiothorac Vasc Anesth 1995; 9: 168–73.[Medline]
4 Kaufmann CR, Dwyer KM, Crews JD, Dols SJ, Trask AL. Usefulness of thrombelastography in assessment of trauma patient coagulation. J Trauma 1997; 42: 716–22.[Medline]
5 Sharma SK, Vera RL, Stegall WC, Whitten CW. Management of a postpartum coagulopathy using thrombelastography. J Clin Anesth 1997; 9: 243–7.[Medline]
6 Sharma SK, Philip J, Wiley J. Thromboelastographic changes in healthy parturients and postpartum women. Anesth Analg 1997; 85: 94–8.[Abstract]
7 Zambruni A, Thalheimer U, Leandro G, Perry D, Burroughs AK. Thromboelastography with citrated blood: comparability with native blood, stability of citrate storage and effect of repeated sampling. Blood Coagul Fibrinolysis 2004; 15: 103–7.[Medline]
8 Bowbrick VA, Mikhailidis DP, Stansby G. The use of citrated whole blood in thromboelastography. Anesth Analg 2000; 90: 1086–8.
9 Camenzind V, Bombelli T, Seifert B, et al. Citrate storage affects thrombelastograph analysis. Anesthesiology 2000; 92: 1242–9.[Medline]
10 Mancuso A, Fung K, Cox D, Mela M, Patch D, Burroughs AK. Assessment of blood coagulation in severe liver disease using thromboelastography: use of citrate storage versus native blood. Blood Coagul Fibrinolysis 2003; 14: 211–6.[Medline]
11 Vig S, Chitolie A, Bevan DH, Halliday A, Dormandy G. Thromboelastography: a reliable test? Blood Coagul Fibrinolysis 2001; 12: 555–61.[Medline]
12 Sorensen B, Johansen P, Christiansen K, Woelke M, Ingerslev J. Whole blood coagulation thrombelastographic profiles employing minimal tissue factor activation. J Thromb Haemost 2003; 1: 551–8.[Medline]
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
