Coagulation
Coagulation laboratory tests
Ecarin clotting time

Author: Jeremy Parsons, M.D. (see Authors page)

Revised: 11 May 2016, last major update June 2012

Copyright: (c) 2002-2012, PathologyOutlines.com, Inc.

PubMed Search: Ecarin clotting time

Table of Contents
Definition / General
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 to 29.0 seconds
    • Prolonged if hirudin or argatroban (direct thrombin inhibitors) present; also hypofibrinogenemia, dysfibrinogenemia
    • False positive if prothrombin deficiency is present