Hematology lec 3 : Coagulation and bleeding disorders (Hemostasis) Flashcards
A 32-year old woman observes the presence of multiple petechiae, purpura and ecchymosis rashes when she wakes up in the morning . She had a history of epistaxis requiring cauterization.
- Platelet count 50 x 109/L (RI 150-400 x 109/L)
- Bleeding time 10 min (RI 2-7 min)
This woman might be suffering from???????
Immune thrombocytopenic purpura
Components of hemostasis
- normal blood vessels
- clotting cascade
- platelets
Hemostasis depends on a delicate balance between ………………….and …………… mechanisms
procoagulant , anticoagulant
Mechanismm of intrinsic pathway of blood coagulation
XIIa + XIa + lXa + Xa
اتناشر حداشر تسعة بمساعدة تمانية يبدأ الكومن باثوي ب عشرة
Mechanism of Extrinsic pathway of blood coagulation
Tissue factor + VIIa + Xa
باثوي قصير وكل حاجة فيه بسيطة
Mechanism of coagulation common pathway
Xa + (prothrombin) II to (thrombin) IIa , then Fibrinogen to Fibrin
نووتتسس عشرة محتاج مساعدة من خمسة(نصه التاني) والكالسيوم
Test of intrinsic pathway :
PTT
Test of Extrinsic pathway :
PT
Screening tests: done for all suspected patients
⚫Bleeding time ⚫Platelet count ⚫Prothombin time (PT) ⚫Partial thromboplastin time (PTT) ⚫Thrombin time (TT)
Specific tests : done according to results of……………….
screening tests
Bleeding time Affected by
�Platelet count
�Platelet function
�Vessel wall
Normal range OF Bleeding time
Ivy’s method: up to 7 min
Causes of prolonged bleeding time:
1-Thrombocytopenia (moderate or severe). 2-Disorders of platelet function: Thrombasthenia 3-Vascular abnormalities
Normal platelet count =
150-400 x109/L
Investigation of a case of thrombocytopenia
⚫ History
⚫ CBC
⚫ Bone Marrow
⚫ ANA
QUALITATIVE PLATELET
DEFECT (Thrombasthenia)
In a case presenting with …………….. and
……………………………….
purpura , normal platelet count
PROTHROMBIN TIME (PT) Test for ……………….
extrinsic pathway (FVII, FX, FV , FII, FI) - [majority are vitamin K dependent factor].
Normal range of PROTHROMBIN TIME (PT):
10-14 sec
Causes of prolonged PT
�Oral anticoagulants �Liver disease �Vit K deficiency (FII, VII , IX and X ) �Congenital deficiency of factors involved in extrinsic pathway. �DIC �inhibitors
PARTIAL THROMBOPLASTIN TIME (PTT) It is a test for
intrinsic pathway of blood coagulation (FVIII, FIX, FXI, FXII, FII, FV, X).
PARTIAL THROMBOPLASTIN TIME (PTT) It is a test Used for patients receiving……………. therapy
heparin
Normal range of PARTIAL THROMBOPLASTIN TIME (PTT): ……………………..
30-40 sec
Causes of prolonged PTT
�Heparin �Deficiency of factors involved in intrinsic pathway, usually congenital: Hemophilia A Hemophilia B and von Willebrand disease) �DIC �Massive transfusion (labile FV, FVIII) �Inhibitors
Prolonged (BT) + Prolonged APTT+ Normal PT
Von Willebrand Disease
Prolonged (BT) + Prolonged APTT+ Prolonged PT
Massive Liver Disease , DIC
- ↑ BT
- ↓Platelet count
- normal (PTT , PT)
immune thrombocytopenic purpura
- ↑PTT
- normal( PT , BT , Platelet count)
Hemophilia A
- ↑PTT
- normal (PT , BT , Platelet count)
Hemophilia B
- ↓Platelet count
- ↑( PT , BT , PTT)
DIC
Group of disorders that predispose to venous thrombosis
thrombophilia
INHERETED THROMBOPHILIA (Heritable thrombophilia)
- Anti-thrombin deficiency
- Protein C deficiency
- Protein S deficiency
- Factor V leiden (FV R 506 Q)
- Prothrombin G20210A mutation
- MTHFR
Acquired thrombophilia
Iatrogenic: surgery -hormonal therapy - chemo/radiotherapy – drugs
Environmental: Age - obesity - pregnancy – trauma –Immobility
Disease related: APS –Neoplasia – MPN – PNH – TTP–
Inflammation – stroke -SCD
DIAGNOSIS of HEREDITARY THROMBOPHILIA
Assays for: AT-III, Protein C Protein S Molecular studies for: FV leiden Prothrombin G20210A Homocysteinaemia
DIAGNOSIS of ACQUIRED THROMBOPHILIA:
• Tests for APS, Lupus Anti-coagulant
Procoagulant
PAI-I
Antiplasmin
Tissue Factor
Clotting Factors
Anticoagulant
Protein S Protein C TFPI Fibrinolytic system AT III
Hemostatic Balance between
1-platelet
2-clotting factors (procoagulant)
3- fibrinolytic system (anticoagulant)
Types of bleeding disorders
- Disorders of Blood vessels e.g. Scurvy, senile purpura
- Disorders of Platelets decrease count (Thrombocytopenia) or impaired function Thrombasthenia
- Disorders of Coagulation e.g decrease amount of clotting factor
◦ Decrease platelet count less than 150.000 may be due to
◦ Decrease production like in aplastic anemia
◦ Increase destruction like ITP immune thrombocytopenic purpura
Thrombasthenia Impaired platelet function may be congenital like ………………………….. or acquired e.g. …………….
von Willebrand disease , Aspirin therapy
von Willebrand factor: Carrier of factor……………..Anchors platelets to subendothelium
VIII
Inheritance of von Willebrand disease
Autosomal dominant
Bleeding in Liver Disease
Decreased synthesis of………………………….
Prolongation of …………………………
II, VII, IX, X, XI, and fibrinogen,
PT, aPTT and Thrombin Time
(bone marrow disorder lead to increase platelet productions from megakaryocyte ) we call it ……………………
essential thrombocytosis
A 31 years old previously healthy man noticed some mild swelling in his left forearm following
his daily workout, which involved doing pushups and lifting weights. Two weeks later he
developed left shoulder pain and some bluish discoloration of the arm. A Doppler ultrasound
showed a DVT in the left subclavian and proximal internal jugular veins. He was treated with
low molecular weight heparin and transitioned to warfarin. 3 days later he is developing
irregular heartbeat and dyspnea , what is the most probable ?
PULMONARY EMBOLISM
