[Hema 2 Lab] M3 - Clot Retraction

Module 3Clot Retraction

PREPARED BY:JEANNETTE SOCORRO B, CRUZ, RMT, MSMT

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Reference Material

CEU Laboratory Manual for Hematology 2

learning objectives

Introduction to Clot Retraction

Have you noticed this happen to your blood sample?

Blood Clot Retraction

• In Vivo: Clot retraction is the “shrinking” of a blood clot over a number of days. The edges of the blood vessel wall at the point of injury are slowly brought together to repair the damage.
• In Vitro: When blood clotting is complete, the clot normally undergoes retraction, wherein, serum is expressed from the clot and the clot becomes denser.

Single Tube Method

PROCEDURE

REFERENCE RANGE

Clot Retraction In Vitro

Sample Computation:Volume of Serum Expressed = 3 mLVolume of Blood Extracted = 5 mL*as stated in the procedure % of Serum Expressed = 60%

Hirshboeck Method or Castor Oil Method

materials

PROCEDURE

REFERENCE RANGE

Clinical Significance

• In platelet disorders such as Glanzmann’s thrombasthenia and thrombocytopenia, clot retraction is impaired or decreased
• In paraproteinemias, clot retraction is abnormal.
• In dysfibrinogenemia and hypofibrinogenemia, the clot formed is small. There will also be RBC fall out, wherein there is increased amounts of red blood cells expressed from the clot.
• If the patient has increased RBC Count, clot retraction is decreaed.
• If the patient has decreased RBC Count (Anemia), clot retraction is increased.

Recap

- Clot retraction occurs after secondary hemostasis - Clot retraction is when the clot shrinks or retracts. - There are two methods to measure clot retraction: - Single Tube Method - Hirshboeck Method or Castor Oil Method

End of Module