Disseminated intravascular coagulation
Revision as of 05:16, 6 June 2015 by Rossdonaldson1 (talk | contribs)
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 of DIC
- 10%–20% of pts w/ Gram-neg sepsis have DIC
- Septic pts more likely to have bleeding than thrombosis
- More likely to develop in asplenic pts or cirrhosis
- Carcinoma
- DIC is often chronic and compensated
- Thrombosis is more common than bleeding
- Leukemia
- More likely to have bleeding than thrombosis
- Trauma
- Brain injury, crush injury, burns, rhabdo, fat embolism
- Liver disease
- May have chronic compensated DIC; acute DIC may occur in setting of acute liver failure
- Pregnancy
- Abruption, Amniotic Fluid Embolus, septic abortion, HELLP syndrome
- Envenomation
- Rattlesnakes and other vipers
- Bleeding not as serious as expected from lab values
- ARDS
- 20% of pts with ARDS develop DIC; 20% of pts with DIC develop ARDS
- Transfusion reactions
Clinical Features
- In given pt either bleeding or thrombosis will predominate
- Bleeding is more common (65% of pts)
- Ranges from petechiae/ecchymosis to life-threatening GI/CNS/pulm bleeding
- Shock occurs in 15%
- Renal failure (25-40%)
- Hepatic dysfunction (19%)
- Respiratory dysfunction (16%)
- Thromboembolism (7%)
- CNS involvement (2%)
- Purpura fulminans (widespread arterial and venous thromboses)
- Associated w/ significant bacteremia
- Bleeding is more common (65% of pts)
Differential Diagnosis
- TTP-HUS
- Pts usually have little or no prolongation of PT or PTT
- 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
- Heparin-induced thrombocytopenia
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 |
Diagnosis
- Acute DIC
- 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)
- Platlets
- Chronic DIC
- FDP: Elevated
- D-dimer: Elevated
- Platelet: Variable
- Fibrinogen: Normal-elevated
- PT: Normal
- PTT: Normal
- RBCs
- Fragmented
Treatment
- Treat underlying illness
- Replacement tx
- Only indicated in pts w/ documented DIC + bleeding or impending procedure
- Fibrinogen
- Consider repletion w/ 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 in pts w/ thromboembolic predominant symptoms from chronic DIC
- Only indicated in pts w/ documented DIC + bleeding or impending procedure