Lab

Whole Blood Clotting Time

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Whole Blood Clotting Time, Whole Blood Clotting Test, Lee-White Clotting Time

  • See Also
  1. Intrinsic Clotting Pathway
  2. Partial Thromboplastin Time (PTT)
  • Background
  1. Time for blood to clot in a glass tube (clotting activated by contact with glass surface)
  2. Reflects integrity of the Intrinsic Clotting Pathway
  • Indications
  1. Snake Bite with Snake Envenomation
    1. Used to identify Coagulopathy after pit viper Envenomation
    2. Poor Test Sensitivity
    3. Isbister (2013) QJM 106(10):925-32 +PMID:23674721 [PubMed]
  • Lab
  • Normal
  1. Whole Blood Clotting Time: 9-15 minutes
  • Technique
  1. Venous blood (2 ml) is drawn into an empty test tube
  2. Test tube is kept upright for 20 minutes
  3. Tube is flipped upside down at 20 minutes and considered abnormal if not fully clotted
    1. Grade 1: Friable clot
    2. Grade 2: No Clot Formation
  • Interpretation
  • Prolonged Whole Blood Clotting Time
  1. Any defect in the Intrinsic Clotting Pathway will prolong the Whole Blood Clotting Time
  • Resources
  1. Whole Blood Clotting Test
    1. https://www.snakebitefoundation.org/whole-blood-clotting-test-wbct