Advertisement

Haemostasis pp 155-167 | Cite as

Activated Clotting Time (ACT)

  • Stephen Horton
  • Simon Augustin
Protocol
Part of the Methods in Molecular Biology book series (MIMB, volume 992)

Abstract

The standard assay for monitoring anticoagulation during extracorporeal life support (ECLS) is the activated clotting time (ACT) test, with celite, kaolin, and glass beads being the most commonly used activators to initiate contact activation. The point-of-care ACT test has been the preferred test in catheterization labs and cardiac theatres because it has a number of advantages over laboratory tests (Spinler et al., Ann Pharmacother 39(7–8):1275–1285, 2005):
  • Shorter time between sampling and results.

  • Smaller blood sample size.

  • Availability to have test performed by non-lab personnel.

  • Reduced errors associated with sample mislabeling/mishandling.

  • Decreased risk of sample degradation with time.

There are other coagulation monitoring tests available; however these are usually specific and do not take into account the global picture of the entire clotting system. The standard coagulation tests (prothrombin time (PT), activated partial thromboplastin time, thrombin time (TT), and fibrinogen level) are plasma tests measuring plasma haemostasis and not patient haemostasis. The ACT measurement uses whole blood, thereby incorporating the importance of platelets and phospholipids in the role of coagulation. Many of the problems with the haemostatic system during ECLS are caused by the activation of platelets, which are not detected by standard tests.

Because an ACT test is nonspecific there are many variables such as hypothermia, platelets, aprotinin, GP IIb/IIIa antagonists, haemodilution, etc. that can alter its results. For this reason it is important to gain an understanding as to how these variables interact for meaningful interpretation of the ACT test result.

Key words

Activated clotting time Coagulation monitoring Whole blood coagulation time Hemotec Hemochron MAX-ACT 

References

  1. 1.
    Royston D (1996) Preventing the inflammatory response to open-heart surgery: the role of Aprotinin and other protease inhibitors. Int J Cardiol 53(suppl):S11–S37PubMedCrossRefGoogle Scholar
  2. 2.
    Despotis GJ, Gravlee G, Filos K, Levy J (1999) Anticoagulation monitoring during cardiac surgery. Anesthesiology 91:1122–1151PubMedCrossRefGoogle Scholar
  3. 3.
    Ammar T, Scudder LE, Coller BS (1997) In vitro effects of platelet Glycoprotein IIb/IIIa receptor antagonist c7E3 Fab on the activated clotting time. Circulation 95:614–617PubMedCrossRefGoogle Scholar
  4. 4.
    Despotis GJ, Summerfield AL, Joist JH et al (1994) Comparison of activated coagulation time and whole blood heparin measurements with laboratory plasma anti-Xa heparin ­concentrations in patients having cardiac operations. Thorac Cardiovasc Surg 108: 1076–1082Google Scholar
  5. 5.
    Spinler SA, Wittkowsky AK, Nutescu EA, Smythe MA (2005) Anticoagulation monitoring part 2: unfractionated heparin and low-molecular-weight heparin. Ann Pharmacother 39(7–8):1275–1285PubMedCrossRefGoogle Scholar
  6. 6.
    Avidan MS, Alcock EL, Da Fonseca J, Ponte J, Desai JB, Despotis GJ, Hunt BL (2004) Comparison of structured use of routine laboratory tests or near-patient assessment with clinical judgement in the management of bleeding after cardiac surgery. Br J Anaesth 92:178–186PubMedCrossRefGoogle Scholar
  7. 7.
    Hattersley PG (1966) Activated clotting time of whole blood. JAMA 196:436–440PubMedCrossRefGoogle Scholar
  8. 8.
    Graves DF, Chernin JM, Kurusz M, Zwischenberger JB (1996) Anticoagulation practices during neonatal extracorporeal membrane oxygenation: survey results. Perfusion 11:461–466PubMedCrossRefGoogle Scholar
  9. 9.
    McManus ML, Kevy SV, Bower LK, Hickey PR (1995) Coagulation factor deficiencies during initiation of extracorporeal membrane oxygenation. J Pediatr 126:900–904PubMedCrossRefGoogle Scholar
  10. 10.
    MIMS on-line (2003) Copyright MIMS Australia Pt. Ltd. http://www.mims.com.au
  11. 11.
    van Oeveren W, Harder MP, Roozendaal KJ, Eijsman L, Wildevuur CRH (1990) Aprotinin protects platelets against the initial effect of cardiopulmonary bypass. J Thorac Cardiovasc Surg 99:788–797PubMedGoogle Scholar
  12. 12.
    Khan TA, Bianchi C, Voisine P, Sandmeyer J, Feng J, Sellke FW (2005) Aprotinin inhibits platelet aggregation and thrombosis. Ann Thorac Surg 79:1545–1550PubMedCrossRefGoogle Scholar
  13. 13.
    Wang JS, Lin CY, Hung WT, Karp RB (1992) Monitoring of heparin-induced anticoagulation with kaolin-activated clotting time in cardiac surgical patients treated with Aprotinin. Anesthesiology 77(6):1080–1084PubMedCrossRefGoogle Scholar
  14. 14.
    Dietrich W, Jochum M (1995) Effect of celite and kaolin on activated clotting time in the presence of Aprotinin: activated clotting time is reduced by binding of Aprotinin to kaolin. J Thorac Cardiovasc Surg 109:177–186PubMedCrossRefGoogle Scholar
  15. 15.
    Machin D, Devine P (2005) The effect of temperature and Aprotinin during cardiopulmonary bypass on three different methods of activated clotting time measurement. J Extra Corpor Technol 37(3):265–271PubMedGoogle Scholar
  16. 16.
    Wolberg AS, Meng ZH, Monroe DM 3rd, Hoffman M (2004) A systematic evaluation of the effect of temperature on coagulation enzyme activity and platelet function. J Trauma 56(6):1221–1228PubMedCrossRefGoogle Scholar
  17. 17.
    Kase PB, Dearing JP (1985) Factors affecting activated clotting time. J Extra Corpor Technol 17(1):27–30Google Scholar
  18. 18.
    Hashimoto K, Yamagishi M, Sasaki T, Nakano M, Kurosawa H (1995) Heparin and Antithrombin III levels during cardiopulmonary bypass: correlation with subclinical plasma coagulation. Ann Thorac Surg 58:799–805CrossRefGoogle Scholar
  19. 19.
    Kadakia RA, Baimeedi SR, Ferguson JJ (2004) Low-molecular-weight heparins in the cardiac catheterization laboratory. Tex Heart Inst J 31(1):72–83PubMedGoogle Scholar
  20. 20.
    Marmur JD, Anand SX, Bagga RS, Fareed J, Pan CM, Sharma SK, Richard MF (2003) The activated clotting time can be used to monitor the low molecular weight heparin dalteparin after intravenous administration. J Am Coll Cardiol 41:394–403PubMedCrossRefGoogle Scholar
  21. 21.
    Operation manual. MAX-ACT activated clotting time test. Helena Laboratories point of care. Beaumont, Texas, USAGoogle Scholar
  22. 22.
    Operation manual. Hemotec ACT II activated clotting time test. Medtronic. Minneapolis, MN, USAGoogle Scholar
  23. 23.
    Instrument operator manual. Hemochron Jr.signature whole blood microcoagulation system – International Technidyne Corporation. Edison, NJ, USAGoogle Scholar
  24. 24.
    Instrument operator manual, HEMOCHRON® response activated clotting time test – International Technidyne Corporation. Edison, NJ, USAGoogle Scholar
  25. 25.
    Koster A, Despotis G, Gruendel M, Fischer T, Praus M, Kuppe H, Levy J (2002) The plasma supplemented modified activated clotting time for monitoring of heparinization during cardiopulmonary bypass: a pilot investigation. Anesth Analg 95:26–30PubMedCrossRefGoogle Scholar
  26. 26.
    Gil W (2001) Inflammo-coagulatory response, extrinsic pathway thrombin generation and a new theory of activated clotting time interpretation. Perfusion 16:27–35PubMedCrossRefGoogle Scholar
  27. 27.
    Horton SB, Butt WW, Mullaly RJ, Thuys CA, O’Connor EB, Byron K, Cochrane AD, Brizard CP, Karl TR (1999) IL-6 and IL-8 levels following cardiopulmonary bypass are not affected by surface coating. Ann Thorac Surg 68:1751–1755PubMedCrossRefGoogle Scholar
  28. 28.
    Bosch YPJ, Ganushchak YM, de Jong DS (2006) Comparison of ACT point-of-care measurements: repeatability and agreement. Perfusion 21:27–31PubMedCrossRefGoogle Scholar
  29. 29.
    El Rouby S, Cohen M, Gonzales A, Hoppensteadt D, Lee T, Zucker ML, Khalid K, LaDuca FM, Fareed J (2006) The use of Hemochron® Jr. Hemonox™ point of care test in monitoring the anticoagulant effects of enoxaparin during interventional coronary procedures. J Thromb Thrombolysis 21: 137–145PubMedCrossRefGoogle Scholar
  30. 30.
    Yamada T, Katori N, Tanaka K, Takeda J (2007) Impact of Sonoclot hemostasis analysis after cardiopulmonary bypass on postoperative hemorrhage in cardiac surgery. J Anesth 21: 148–152PubMedCrossRefGoogle Scholar
  31. 31.
    Shore-Lesserson L, Manspeizer HE, DePerio M, Francis S, Vela-Cantos F, Ergin MA (1999) Thromboelastography-guided transfusion algorithm reduces transfusions in complex cardiac surgery. Anesth Analg 88:312–319PubMedGoogle Scholar

Copyright information

© Humana Press 2013

Authors and Affiliations

  • Stephen Horton
    • 1
  • Simon Augustin
    • 1
  1. 1.Department of Cardiac SurgeryRoyal Children’s HospitalMelbourneAustralia

Personalised recommendations