Coagulation laboratory tests

Ecarin clotting time

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PubMed Search: Ecarin clotting time

Jeremy C. Parsons, M.D.
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Table of Contents
Definition / general
Cite this page: Parsons JC. Ecarin clotting time. website. Accessed November 29th, 2023.
Definition / general
  • Measures activity of hirudin in plasma, important since severe bleeding can occur with hirudin overdose and no antidote is known
  • Also measures activity of lepirudin, a recombinant form of hirudin (J Extra Corpor Technol 2001;33:117)
  • Ecarin catalyzes prothrombin to meizothrombin, an active form that is inhibited by hirudin (Pathophysiol Haemost Thromb 2004;33:173)
  • Test measures ability of hirudin to complex with / inhibit meizothrombin as ecarin produces it from prothrombin
  • Ecarin comes from the venon of the saw - scaled viper

  • Specimen:
    • Sodium citrate tube filled to top
    • Freeze immediately until testing occurs
    • Specimens with clots or hemolysis are unacceptable, unless hemolysis is due to cardiopulmonary bypass and is produced in vivo
    • Do not draw from heparinized catheter

  • Reference range:
    • 22.6 - 29.0 seconds
    • Prolonged if hirudin or argatroban (direct thrombin inhibitors) present; also hypofibrinogenemia, dysfibrinogenemia
    • False positive if prothrombin deficiency is present

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