Evaluation of Bleeding Tendencies

Initial Assessment - Bleed Detectives

• Focused History:
  • Onset & Type: Spontaneous vs. post-trauma/surgery? Neonatal onset?
  • Sites: Mucocutaneous (epistaxis, gum bleed, menorrhagia) vs. deep tissue (hemarthrosis, muscle hematoma).
  • Severity & Frequency: Quantify if possible.
  • Family History: Bleeding disorders? Consanguinity?
  • Drug History: NSAIDs, anticoagulants.
  • Systemic Illness: Liver/renal disease, infections.
• Clinical Examination:
  • Skin/Mucosa: Petechiae (<2mm), purpura (2mm-1cm), ecchymoses (>1cm), hematomas.
  • Joints: Hemarthrosis (swelling, pain, restricted movement).
  • General: Pallor, jaundice, hepatosplenomegaly.

⭐ Mucocutaneous bleeding (gums, nose, GI, menorrhagia) suggests platelet disorders or von Willebrand disease; deep tissue bleeding (joints, muscles, CNS) suggests coagulation factor deficiencies.

Lab Investigations - Initial Clues

• Initial Screening Tests:
  • CBC: Platelet count.
  • PT: Extrinsic & common pathways.
  • aPTT: Intrinsic & common pathways.
  • BT/PFA-100: Platelet function, vWD screen.

⭐ A mixing study (patient plasma + normal plasma) helps differentiate factor deficiency (correction of PT/aPTT) from a factor inhibitor (no correction).

Primary Hemostasis Disorders - Plug Problems

Mucocutaneous bleeds (petechiae, epistaxis). Labs: PT/aPTT normal, ↑BT/PFA-100.

• Immune Thrombocytopenic Purpura (ITP)

  • Patho: Anti-GpIIb/IIIa Abs → ↓platelets.
  • Features: Isolated ↓Plt, post-viral (kids).
  • BM: ↑Megakaryocytes.

• von Willebrand Disease (vWD)

  • Patho: vWF def./defect (binds FVIII).
  • Labs: ↑BT/PFA, ↓vWF:Ag, ↓Risto. Cof; Plt N/↓; aPTT often ↑.

  ⭐ von Willebrand Disease is the most common inherited bleeding disorder, typically presenting with mucocutaneous bleeding and often a normal platelet count but prolonged PFA-100/Bleeding Time.

• Bernard-Soulier Syndrome (BSS)

  • Patho: GpIb defect (adhesion); AR.
  • Features: Thrombocytopenia, GIANT platelets.
  • Labs: ↓Plt (giant), ↑BT. No Ristocetin agg.

• Glanzmann Thrombasthenia (GT)

  • Patho: GpIIb/IIIa defect (aggregation); AR.
  • Features: Normal platelet count.
  • Labs: Normal Plt, ↑BT. No ADP/collagen/epi agg.

• Drug-induced Platelet Dysfunction

  • Aspirin (irreversible), NSAIDs (reversible): ↓TXA2 → impaired aggregation.

Secondary Hemostasis Disorders - Factor Fumbles

• Hemophilia A: Factor VIII↓. X-linked recessive. Deep bleeds (joints, muscles). Lab: ↑aPTT; Normal PT, Platelet count, BT.
• Hemophilia B (Christmas Disease): Factor IX↓. X-linked recessive. Clinically like Hemophilia A. Lab: ↑aPTT; Normal PT, Platelet count, BT.

⭐ Hemophilia A (Factor VIII deficiency) and Hemophilia B (Factor IX deficiency) are X-linked recessive disorders characterized by prolonged aPTT with normal PT and platelet count.

• Vitamin K Deficiency: Factors II, VII, IX, X, Protein C, S↓. Acquired (e.g., antibiotics, warfarin). Lab: ↑PT (early, due to FVII short half-life), then ↑aPTT.
• Von Willebrand Disease (vWD): vWF↓ (stabilizes FVIII). Autosomal Dominant (most common type). Mucocutaneous bleeding. Lab: Often ↑BT, may have ↑aPTT (due to FVIII↓). Normal PT, Platelet count usually normal.

High‑Yield Points - ⚡ Biggest Takeaways

• Initial screening: CBC (platelets), PT, aPTT are crucial first steps.
• Isolated thrombocytopenia often suggests Immune Thrombocytopenic Purpura (ITP).
• Prolonged aPTT with normal PT points to Hemophilia A/B or vWD (severe).
• Von Willebrand Disease (vWD) is the most common inherited bleeding disorder; presents variably.
• Mixing studies differentiate factor deficiency (corrects) from inhibitors (no correction).
• Vitamin K deficiency classically prolongs PT more than aPTT.
• Platelet function defects (e.g., Glanzmann's) show normal platelet count but abnormal function tests.