Bleeding Disorders

Question 1

Causes of bleeding disorders

Answer 1

Pg 428

Question 2

Screening tests for bleeding disorders

Answer 2

1. Bleeding time
2. Clotting time
3. Prothrombin time
4. Activated partial thromboplastin time
5. Thrombin time
6. Fibrinogen assay
7. Platelet count

Pg 431

Question 3

Expected changes in screening tests in ITP, hemophila, DIC

Answer 3

1. ITP:

• Platelet count ↓
• Bleeding time ↑

2. Hemophilia:

• Clotting time ↑
• APTT ↑

3. DIC:

• Platelet count ↓
• Bleeding time ↑
• Clotting time ↑
• PT ↑
• APTT ↑
• TT ↑
• Fibrinogen ↓
• D-dimer ↑↑

Pg 433

Question 4

Causes of thrombocytopenia

Answer 4

Pg 434

Question 5

Lab dx of IDP (idiopathic thrombocytopenic purpura)

Answer 5

1. Routine Tests:

a. Hb% – Normal or slightly reduced

b. ESR – Normal

2. Peripheral Blood Film (PBF):

a. RBC – Normocytic, normochromic

b. WBC – Normal

c. Platelets – Markedly reduced; large/giant platelets present

3. Screening Tests:

a. Bleeding Time (BT) – Prolonged

b. Clotting Time (CT) – Normal

c. Platelet Count – Reduced (<1 lakh/mm³ common)

d. Tourniquet Test – Positive in most cases

4. Bone Marrow:

a. Cellularity – Normal or hypercellular

b. M:E Ratio – Normal or mildly increased

c. Erythropoiesis – Normal

d. Granulopoiesis – Normal

e. Megakaryopoiesis – Increased megakaryocytes, many immature forms

5. Other Tests:

• Anti-platelet antibodies – May be positive (not required for diagnosis)

Pg 436

Question 6

Classify coagulation disorders

Answer 6

1. Congenital

• Haemophilias:
  • Haemophilia A – Classical haemophilia (Factor VIII deficiency)
  • Haemophilia B – Christmas disease (Factor IX deficiency)
• Von Willebrand’s disease – Factor VIII–related antigen deficiency / vWF deficiency
• Other congenital deficiency disorders:
  • Deficiency of actor I, II, V, VII, X, XI, XII, XIII, Fletcher factor, Fitzgerald factor

2. Acquired:

• Disseminated intravascular coagulation (DIC)
• Vitamin K deficiency
• Liver disease
• Anticoagulant drugs
• Acute primary fibrinolysis
• Massive blood transfusion
• Circulating inhibitors of coagulation

Pg 438

Question 7

Hemophilia characteristics

Answer 7

1. Sex-linked recessive inheritance (almost all patients are males).
2. Normal bleeding time and platelet count.
3. Normal PT (prothrombin time).
4. Prolonged APTT (defective intrinsic pathway).
5. Normal platelet function (no petechiae, no purpura).
6. Deep tissue bleeding:

• Hemarthrosis (bleeding into joints)
• Muscle hematomas
• Retroperitoneal hemorrhage

7. Bleeding is delayed and prolonged after trauma or surgery.
8. Severity correlates with clotting factor level (Factor VIII in Hemophilia A, Factor IX in Hemophilia B).
9. Mixing test corrects the APTT (because the deficiency is of a factor, not an inhibitor).

Pg 440

Question 8

Lab dx of hemophilia

Answer 8

1. Screening Tests

a. Clotting time – Prolonged

b. Activated partial thromboplastin time – Prolonged

c. Prothrombin time – Normal

d. Bleeding time – Normal

e. Platelet count – Normal

f. Thrombin time – Normal

g. Tourniquet test - Usually normal

2. Confirmatory Tests

a. Factor VIII activity – Reduced in Hemophilia A

b. Factor IX activity – Reduced in Hemophilia B

Pg 441