Investigations of a case suffering from bleeding disorders

 Investigations of a case suffering from bleeding disorders

Bleeding Disorders

Hemostasis

 

  

• Hemostasis is the arrest of blood flow and control of hemorrhage from an injured blood vessel.

The entire mechanism of hemostasis can be divided into three parts: 

1. Extravascular effects

             2. Vascular effects:

i.     Vasoconstriction: serotonin by plasma

ii. Platelet Plug: collagen contact with platelet and platelet release ADP then serotonin and factor 3 participates in coagulation.

 

             3. Intravascular effects: Intrinsic factor to form a fibrin clot.

When investigating a case of bleeding disorder, the goal is to identify whether the problem lies in platelets, coagulation factors, or blood vessels. The structured outline of the clinical evaluation and laboratory investigations usually done by following parameters:

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1. Clinical Evaluation

Before laboratory testing, gather a detailed history and physical examination:

• History
• Onset and duration of bleeding (since childhood or recent)
• Site and type of bleeding (skin, gums, joints, GI tract, etc.)
• Family history of similar disorders
• Drug history (e.g., aspirin, anticoagulants)
• History of infections, liver disease, or autoimmune conditions
• Physical Examination
• Look for petechiae, ecchymosis, purpura
• Joint swelling (suggests hemophilia)
• Signs of liver disease or splenomegaly

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2. Basic Laboratory Investigations

These initial tests help categorize the bleeding disorder:

Test	Purpose	Possible Interpretation
Complete Blood Count (CBC)	Evaluate platelet count and hemoglobin	Thrombocytopenia suggests platelet disorder
Peripheral Blood Smear	Assess platelet morphology and RBC shape	Large platelets (Bernard-Soulier), schistocytes (DIC)
Bleeding Time (BT)	Assess platelet function and vessel integrity	Prolonged in platelet disorders, von Willebrand disease
Prothrombin Time (PT)	Assesses extrinsic & common pathways (factors I, II, V, VII, X)	Prolonged in liver disease, vitamin K deficiency, warfarin therapy
Activated Partial Thromboplastin Time (aPTT)	Assesses intrinsic & common pathways (factors VIII, IX, XI, XII)	Prolonged in hemophilia, heparin therapy
Thrombin Time (TT)	Evaluates final step of coagulation (fibrinogen → fibrin)	Prolonged in dysfibrinogenemia, heparin presence
Platelet Function Tests (PFA-100, Aggregation Studies)	Assess functional defects in platelets	Abnormal in Glanzmann thrombasthenia, aspirin effect
Fibrinogen Level	Quantify fibrinogen concentration	Low in DIC, liver disease
D-dimer Test	Detect fibrin degradation products	Elevated in DIC, thrombosis, severe inflammation

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3. Specific/Confirmatory Tests

Once screening tests narrow the cause:

• Mixing Studies – To differentiate factor deficiency from inhibitors (e.g., lupus anticoagulant)
• Specific Factor Assays – Measure levels of Factors VIII, IX, XI, etc.
• von Willebrand Factor Assays – vWF antigen, ristocetin cofactor activity
• Liver Function Tests – To rule out hepatic synthesis problems
• Bone Marrow Examination – If thrombocytopenia is unexplained

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4. Interpretation Summary

Pattern	Likely Disorder
Low platelet count, prolonged BT, normal PT & aPTT	Platelet disorder (e.g., ITP)
Normal platelet count, prolonged BT, prolonged aPTT	von Willebrand disease
Normal platelet count, normal BT, prolonged aPTT	Hemophilia A or B
Normal platelet count, prolonged PT & aPTT	Severe liver disease or DIC
Low fibrinogen, elevated D-dimer	DIC

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5. Additional/Advanced Tests (if required)

• Genetic testing (e.g., F8 gene mutation in Hemophilia A)
• Flow cytometry for platelet surface glycoproteins
• Coagulation factor inhibitor assays
• Vitamin K level estimation

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