Thromboembolic complications

Thromboembolic complications

Thromboembolic complications

On this page

Virchow's Triad - The Clotting Trifecta

Virchow's Triad and LV Thrombosis

Three primary abnormalities in blood composition, flow, and vessel wall that predispose to thrombosis. 📌 Mnemonic: SHE

  • Stasis: Reduced blood flow.
    • Immobilization (post-op, paralysis, long travel).
    • Cardiac dysfunction (atrial fibrillation, heart failure).
  • Hypercoagulability: Increased tendency to clot.
    • Inherited: Factor V Leiden, prothrombin gene mutation.
    • Acquired: Malignancy, pregnancy, OCPs, sepsis.
  • Endothelial Injury: Damage to the vessel lining.
    • Trauma, surgery, IV catheters, atherosclerosis.

⭐ Factor V Leiden is the most common inherited thrombophilia, causing resistance to activated protein C.

DVT Diagnosis & Management - Deep Trouble Leg Day

  • Diagnosis:
    • Wells Score: Stratifies pre-test probability. >2 = DVT likely.
    • First-line Imaging: Compression ultrasonography with Doppler. Shows non-compressible vein.
    • D-Dimer: High negative predictive value. Used to rule out DVT in low-probability patients (Wells score <2).

Ultrasound of non-compressible popliteal vein (DVT)

  • Management:
    • Anticoagulation: LMWH or DOACs (e.g., apixaban, rivaroxaban) for at least 3 months.
    • IVC Filter: For patients with contraindications to anticoagulation (e.g., active bleeding).

Phlegmasia Cerulea Dolens: A rare, limb-threatening complication of massive DVT causing venous outflow obstruction, intense pain, cyanosis, and edema.

Pulmonary Embolism - Lethal Lung Lodger

  • Pathophysiology: Occlusion of pulmonary arteries, most commonly from a dislodged deep vein thrombus (DVT).
  • Presentation: Sudden-onset dyspnea, pleuritic chest pain, tachypnea, and tachycardia. Hemoptysis can occur.

    • 📌 Virchow's Triad (risk factors): Stasis, Hypercoagulability, Endothelial injury.
  • Diagnosis:

    • Best initial test: CT Pulmonary Angiography (CTPA) is the gold standard.
    • V/Q Scan: Used if CTPA is contraindicated (e.g., renal failure, contrast allergy).
    • D-dimer: High negative predictive value; useful to rule out PE in low-risk patients.

Physiological Dead Space: In PE, ventilated lung segments are not perfused, leading to a profound ventilation/perfusion (V/Q) mismatch. This is the primary cause of hypoxemia.

CT angiogram of saddle pulmonary embolus

  • Management:
    • Anticoagulation: Immediate start with Heparin or LMWH, bridged to Warfarin or a DOAC.
    • Thrombolysis: For massive PE with hemodynamic instability.

VTE Prophylaxis - Clot Blockers United

  • Risk Stratification: Use the Caprini score to guide therapy intensity for surgical patients.
  • Mechanical Methods: Primarily for patients at high risk of bleeding.
    • Intermittent Pneumatic Compression (IPCs).
    • Graduated Compression Stockings (GCS).
  • Pharmacological Agents: The mainstay for moderate-to-high risk patients.
    • LMWH: Enoxaparin 40mg SC daily.
    • UFH: 5000 units SC q8-12h.
    • Fondaparinux: Use if history of HIT.
  • Early Ambulation: A crucial baseline intervention for all postoperative patients.

⭐ Pharmacologic prophylaxis is contraindicated in patients with active bleeding, severe bleeding diathesis, or a platelet count < 50,000/μL.

📌 VTE Prevention: Very Early ambulation, Thrombotics, External compression.

  • Virchow's triad (stasis, hypercoagulability, endothelial injury) is the cornerstone of pathophysiology.
  • Pulmonary embolism (PE) is the most common preventable cause of death in hospitalized patients.
  • Major risk factors include orthopedic/pelvic surgery, malignancy, and prolonged immobility.
  • Prophylaxis is key: early ambulation, pneumatic compression, and pharmacologic agents (LMWH).
  • Diagnose DVT with duplex ultrasound; diagnose PE with CT angiography.
  • Treatment involves systemic anticoagulation; consider an IVC filter if contraindicated.

Practice Questions: Thromboembolic complications

Test your understanding with these related questions

A 32-year-old woman presents with progressive shortness of breath and a dry cough. She says that her symptoms onset recently after a 12-hour flight. Past medical history is unremarkable. Current medications are oral estrogen/progesterone containing contraceptive pills. Her vital signs include: blood pressure 110/60 mm Hg, pulse 101/min, respiratory rate 22/min, oxygen saturation 88% on room air, and temperature 37.9℃ (100.2℉). Her weight is 94 kg (207.2 lb) and height is 170 cm (5 ft 7 in). On physical examination, she is acrocyanotic. There are significant swelling and warmth over the right calf. There are widespread bilateral rales present. Cardiac auscultation reveals accentuation of the pulmonic component of the second heart sound (P2) and an S3 gallop. Which of the following ventilation/perfusion (V/Q) ratios most likely corresponds to this patient’s condition?

1 of 5

Flashcards: Thromboembolic complications

1/8

Patients with volkmann ischemic contracture have significant pain with _____ extension of fingers / wrist

TAP TO REVEAL ANSWER

Patients with volkmann ischemic contracture have significant pain with _____ extension of fingers / wrist

passive

browseSpaceflip

Enjoying this lesson?

Get full access to all lessons, practice questions, and more.

Start Your Free Trial