Coagulopathies

Coagulopathies are disorders of hemostasis in which the normal process of blood clotting is impaired, resulting in excessive bleeding or, less commonly, abnormal thrombosis. These disorders may involve abnormalities in clotting factors, platelets, or the coagulation cascade, and are broadly classified as inherited or acquired.

Hemostasis:

Normally hemostasis occurs in three coordinated stages:

1. Vascular phase – vasoconstriction reduces blood flow
2. Primary hemostasis – platelet adhesion and aggregation form a temporary plug
3. Secondary hemostasis – activation of the coagulation cascade stabilizes the plug with fibrin

Failure at any stage can lead to a coagulopathy.

Classification of Coagulopathies

1. Inherited Disorders

These are usually due to deficiencies or dysfunctions of specific clotting factors:

• Hemophilia A – deficiency of factor VIII
• Hemophilia B – deficiency of factor IX
• Von Willebrand disease – defect in von Willebrand factor affecting platelet adhesion

These typically present early in life with recurrent bleeding episodes.

2. Acquired Disorders

These arise secondary to other conditions:

• Vitamin K deficiency – reduced synthesis of clotting factors
• Liver disease – impaired production of coagulation proteins
• Disseminated intravascular coagulation (DIC) – widespread activation and consumption of clotting factors
• Anticoagulant therapy – drug-induced impairment of coagulation

Pathophysiology

Coagulopathies result from one or more of the following mechanisms:

• Clotting factor deficiency → impaired fibrin formation → delayed bleeding
• Platelet dysfunction → defective primary hemostasis → mucosal bleeding
• Excessive coagulation activation (e.g., DIC) → consumption of factors → bleeding

Clinical Features

Common manifestations include:

• Easy bruising
• Prolonged bleeding after injury
• Spontaneous mucosal bleeding (epistaxis, gum bleeding)
• Hemarthrosis (in hemophilia)
• Petechiae and purpura (platelet-related disorders)

Laboratory Evaluation

Key investigations include:

• Prothrombin Time (PT) – evaluates extrinsic pathway
• Activated Partial Thromboplastin Time (aPTT) – evaluates intrinsic pathway
• Platelet count
• Fibrinogen and D-dimer levels (especially in DIC)

Comparison of Major Coagulopathies

Feature	Hemophilia A	Hemophilia B	Von Willebrand Disease	Disseminated Intravascular Coagulation (DIC)	Vitamin K Deficiency
Etiology	Factor VIII deficiency	Factor IX deficiency	vWF deficiency/dysfunction	Consumption of clotting factors	Reduced vitamin K–dependent factors
Type	Inherited (X-linked)	Inherited (X-linked)	Inherited (autosomal dominant)	Acquired	Acquired
Hemostatic Defect	Secondary hemostasis	Secondary hemostasis	Primary + secondary hemostasis	Both pathways affected	Secondary hemostasis
Bleeding Pattern	Deep tissue, joints	Similar to A	Mucosal bleeding	Bleeding + thrombosis	Generalized bleeding
PT	Normal	Normal	Normal/slightly ↑	Prolonged	Prolonged
aPTT	Prolonged	Prolonged	Prolonged (variable)	Prolonged	Prolonged
Platelet Count	Normal	Normal	Normal	Decreased	Normal
Bleeding Time	Normal	Normal	Prolonged	Prolonged	Normal/slightly ↑
Management	Factor VIII replacement	Factor IX replacement	Desmopressin	Treat cause, FFP, platelets	Vitamin K