Disseminated intravascular coagulation
Background
- Widespread and inappropriate activation of the coagulation and fibrinolytic systems
- Exposure of blood to procoagulants such as tissue factor and cancer procoagulant
- Formation of fibrin within the circulation
- Fibrinolysis
- Depletion of clotting factors
- End-organ damage
- Chronic DIC occurs when hepatic/bone marrow production balances coag factor consumption
Causes
- Infection (most common cause)
- Carcinoma
- Leukemia
- Trauma
- Brain injury, crush injury, burns, rhabdo, fat embolism
- Liver disease
- Pregnancy
- Abruption, Amniotic Fluid Embolus, septic abortion, HELLP syndrome
- Snake bite
- ARDS
- Transfusion reaction
Clinical Features
In given pt either bleeding or thrombosis will predominate (bleeding is more common ~65%)
- Shock (15%)
- Acute renal failure (25-40%)
- Hepatic dysfunction (19%)
- Respiratory dysfunction (16%)
- Thromboembolism (7%)
- CNS involvement (2%)
- Purpura fulminans (widespread arterial and venous thromboses)
- Associated with significant bacteremia
Differential Diagnosis
- Severe liver disease
- Also a/w prolonged PT/PTT, thrombocytopenia, incr D-dimer, incr FDPs
- However, D-dimer is usually only mildly elevated
- Also a/w prolonged PT/PTT, thrombocytopenia, incr D-dimer, incr FDPs
Microangiopathic Hemolytic Anemia (MAHA)
- Disseminated Intravascular Coagulation (DIC)
- Thrombotic Thrombocytopenic Purpura (TTP)
- Hemolytic Uremic Syndrome (HUS)
- HELLP syndrome
- Heparin-Induced Thrombocytopenia (HIT)
- Hereditary spherocytosis
- Paroxysmal nocturnal hemoglobinuria (PNH)
- Malignant hypertension
- Scleroderma
- Antiphospholipid Syndrome (APS)
- Other medical causes: malignancy, renal allograft rejection, vasculitides like polyarteritis nodosa and Wegener's granulomatosis
- Drugs: chemotherapy; Clopidogrel (Plavix) associated with TTP
- Nonvascular causes: prosthetic valve (more common with mechanical, more common at aortic valve), LVAD, TIPS, coil embolization, patched AV shunt, AVM
Thrombocytopenia
Decreased production
- Marrow infiltration (tumor or infection)
- Viral infections (rubella, HIV)
- Marrow suppression (commonly chemotherapy or radiation)
- Congenital thrombocytopenia
- Fanconi anemia
- Alport syndrome
- Bernand Soulier
- Vitamin B12 and/or folate deficiency
Increased platelet destruction or use
- Idiopathic thrombocytopenic purpura
- Thrombotic Thrombocytopenic Purpura (TTP)
- Hemolytic Uremic Syndrome (HUS)
- Disseminated Intravascular Coagulation (DIC)
- Viral infections (HIV, mumps, varicella, EBV)
- Drugs (heparin, protamine)
- Postransfusion or Posttransplantation
- Autoimmune destruction (SLE or Sarcoidosis)
- Mechanical destruction
- Artificial valves
- ECMO
- HELLP syndrome
- Excessive hemorrhage
- Hemodialysis, extracorporeal circulation
- Splenic Sequestration
- Occurs in Sickle cell disease and Cirrhosis
Drug Induced
- sulfa antibiotics, ETOH, ASA, thiazide diuretics/furosemide
Comparison by Etiology
ITP | TTP | HUS | HIT | DIC | |
---|---|---|---|---|---|
↓ PLT | Yes | Yes | Yes | Yes | Yes |
↑PT/INR | No | No | No | +/- | Yes |
MAHA | No | Yes | Yes | No | Yes |
↓ Fibrinogen | No | No | No | No | Yes |
Ok to give PLT | Yes | No | No | No | Yes |
Coagulopathy
Platelet Related
- Too few
- Nonfunctional
Factor Related
- Acquired (Drug Related)
- Warfarin (Coumadin)
- Unfractionated heparin
- Low molecular weight heparin (i.e. enoxaparin (Lovenox), dalteparin)
- Factor Xa Inhibitors (e.g. rivaroxaban, apixaban, fondaparinux, edoxaban)
- Direct thrombin inhibitors (e.g. dabigatran, argatroban, bivalirudin)
- Illness induced
- Genetic
Diagnosis
Acute
- Platlets
- Low (or dropping)
- Sn, not Sp
- PT
- Prolonged
- Fibrinogen
- Low
- <100 correlates w/ severe DIC
- May be normal (acute phase reactant)
- PTT
- Prolonged
- FDP
- Elevated
- D-dimer
- Elevated
- Sn but not Sp: may also see in pts w/ chronic liver or renal disease
- RBCs
- Fragmented (not specific)
Chronic
- FDP: Elevated
- D-dimer: Elevated
- Platelet: Variable
- Fibrinogen: Normal-elevated
- PT: Normal
- PTT: Normal
- RBCs
- Fragmented
Treatment
- Treat underlying illness
- Replacement treatment
- Only indicated in with documented DIC + bleeding or impending procedure
- Fibrinogen
- Consider repletion with cryoprecipitate to raise level to 100-150
- Platelets
- Consider repletion if <50K w/ bleeding or <20K without bleeding
- FFP
- Vitamin K
- Folate
- Fibrinogen
- Heparin
- Consider only if thromboembolic are predominant symptoms from chronic DIC
- Only indicated in with documented DIC + bleeding or impending procedure