Hematology: Acquired Hypercoagulability

Virchow’s Triad

• Describes the Three Primary Factors that Lead to Increased Risk of Venous Thromboembolism (VTE)
• Triad:
  • Hypercoagulability
  • Venous Stasis – Reduced Flow Decreases the Interaction of Cell Proteins & Natural Anticoagulant Pathways on Endothelial Cell Surfaces
  • Endothelial Wall Injury – Alters Blood Flow Dynamics & Creates Turbulence

Causes

• Smoking – Most Common Cause
• Inflammation/Infection
• COVID-19
• Prolonged Immobilization
  • Prolonged Sitting
  • Extended Travel
  • Bedridden Medical Conditions
• Hospitalization
• Advanced Age
• Recent Major Surgery
  • Postoperative Hypercoagulability Due to Transient Release of Tissue Factor
• Trauma
  • Acute Traumatic Coagulopathy (ATC)/Trauma-Induced Coagulopathy (TIC)
    • *See Trauma: Hemorrhagic Shock & Trauma Resuscitation
  • Highest Risk for VTE: Spinal Cord Injury
  • Even Minor Injuries Can Increase Risk
• Malignancy
  • From Production of Procoagulant Substances
• Pregnancy
• Inflammatory Bowel Disease (IBD)
• Antiphospholipid Syndrome
  • *See Hematology & Oncology: Antiphospholipid Syndrome
• Heart Failure
• Severe Liver Disease
• Obesity
• Chronic Kidney Disease & Nephrotic Syndrome
• IV Drug Abuse
• Drugs:
  • Oral Contraceptives
  • Hormone Replacement Therapy
  • Testosterone
  • Tamoxifen
  • Steroids
  • Antidepressants

Venous Thromboembolism (VTE)

• *See Vascular: Deep Venous Thrombosis (DVT)
• *See Vascular: Pulmonary Embolism (PE)