Thrombotic event is seen in all of the following except:

Idiopathic thrombocytopenic purpura

Paroxysmal nocturnal hemoglobinuria

Thrombotic thrombocytopenic purpura is a syndrome characterized by which of the following?

Thrombocytopenia, anemia, neurological abnormalities, progressive renal failure and fever

Thrombocytopenia, anemia, neurological abnormalities, progressive hepatic failure and fever

Thrombocytopenia, normal anemia, neurological abnormalities, progressive renal failure and fever

Thrombocytopenia, anemia, no neurological abnormalities, progressive renal failure and fever

Thrombotic Disorders for INI-CET: High-Yield Internal Medicine Lessons

Basics & Virchow's Triad - Clot Chaos Crew

Thrombosis (pathological clot) arises from Virchow's Triad (📌 SHE):

Stasis (Abnormal Blood Flow): Slowed circulation.
- E.g., Immobility, atrial fibrillation (AF), DVT history.
Hypercoagulability: ↑ blood's clotting tendency.
- E.g., Factor V Leiden, OCPs, malignancy, pregnancy, antiphospholipid syndrome.
Endothelial Injury: Vessel wall damage.
- E.g., Trauma, surgery, hypertension, smoking, catheters.

⭐ Factor V Leiden is the most common inherited thrombophilia, predisposing to venous thromboembolism.

Inherited Thrombophilias - Bad Blood Genes

These genetic defects predispose to venous thromboembolism (VTE). Most are autosomal dominant (AD).

Condition	Defect	Inheritance	Key Risks/Associations
Factor V Leiden (FVL)	APC resistance ($Arg506Gln$)	AD	📌 Most common; DVT, PE, RPL.
Prothrombin G20210A	↑ Prothrombin levels	AD	2nd common; DVT, PE.
Protein C Deficiency	↓ Protein C	AD	DVT, PE, warfarin-induced skin necrosis, neonatal purpura.
Protein S Deficiency	↓ Protein S	AD	DVT, PE, warfarin-induced skin necrosis.
Antithrombin Deficiency	↓ Antithrombin	AD	DVT, PE, heparin resistance; most severe.

Acquired Thrombophilias - Lifestyle Clot Culprits

Antiphospholipid Syndrome (APLS):
- Criteria: Clinical (thrombosis, pregnancy morbidity) & Lab (📌 LAC: Lupus Anticoagulant, aCL, anti-β2GPI).
Heparin-Induced Thrombocytopenia (HIT):
- Type 1 (mild, early). Type 2 (immune, 5-10 days, thrombotic).
- 4Ts Score (Thrombocytopenia, Timing, Thrombosis, oTher causes):

Malignancy: Trousseau's (migratory thrombophlebitis).
PNH: GPI defect (CD55/59↓), venous thrombosis.
Nephrotic Syndrome: ATIII, Protein C/S loss; ↑ procoagulants.

⭐ HIT Type 2: Abs vs PF4-heparin complex.

DVT/PE - Deep Trouble Clots

DVT: Unilateral leg swelling, pain, warmth, erythema.
PE: Dyspnea, pleuritic chest pain, tachypnea, tachycardia. Massive PE: hypotension.
Wells Score (DVT): Factors: cancer, immobilization, surgery, tenderness, leg/calf swelling (>3cm), edema. Score ≥2: DVT likely.
Wells Score (PE): Factors: DVT signs, PE #1 Dx, HR >100bpm, immobilization/surgery, prior DVT/PE, hemoptysis, cancer. Score >4: PE likely.
Initial Management: Anticoagulation (LMWH, DOACs). Thrombolysis/embolectomy for massive PE/extensive DVT.

⭐ Westermark sign (oligemia), Hampton's hump (wedge infarct), Palla's sign (enlarged right descending PA) are classic (but rare) CXR findings in PE.

Anticoagulant Arsenal - Clot Busters Guide

Class	MOA	Onset	Monitoring	Reversal Agent(s)	Key Side Effect(s)
UFH	Potentiates Antithrombin; inactivates Xa, IIa	Rapid IV	aPTT	Protamine Sulfate	Bleeding, HIT
LMWH	Potentiates Antithrombin; mainly Xa inactivation	Rapid SC	Anti-Xa (renal)	Protamine Sulfate (partial)	Bleeding, ↓HIT risk
Warfarin	Inhibits Vit K epoxide reductase (↓ II,VII,IX,X,C,S)	Slow (days)	PT/INR (2-3)	Vit K, PCC/FFP	Bleeding, Skin necrosis
DOACs	Direct Thrombin (Dabigatran) or Xa inhibitors	Rapid	None routine	Idarucizumab (Dabi), Andexanet alfa (Xa-i)	Bleeding, GI upset

High‑Yield Points - ⚡ Biggest Takeaways

Virchow's triad (stasis, hypercoagulability, endothelial injury) is fundamental to thrombosis.

Factor V Leiden is the most common inherited thrombophilia.

Antiphospholipid syndrome (APS) features arterial/venous thrombosis and recurrent fetal loss; linked to lupus anticoagulant & anticardiolipin antibodies.

Heparin-Induced Thrombocytopenia (HIT) causes paradoxical thrombosis with low platelets after heparin; suspect with platelet drop >50%.

Disseminated Intravascular Coagulation (DIC) involves widespread microthrombi and factor consumption, leading to bleeding and thrombosis.

Thrombotic Thrombocytopenic Purpura (TTP) presents with a pentad (fever, thrombocytopenia, MAHA, renal, neuro); due to ADAMTS13 deficiency.

Warfarin-induced skin necrosis is a risk in Protein C or S deficiency if heparin bridging is inadequate.

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