Disseminated Intravascular Coagulopathy (DIC)

Sample
- Collect the blood for PT and PTT.
- Immediately do assay for clotting factors.
Purpose of the test (Indications)
- To exclude the septicemia.
- Amniotic fluid embolism.
- Retention of the dead fetus.
- Malignant neoplasia.
- In liver cirrhosis.
- Extensive surgery especially on the liver.
- Severe burn.
- Extensive trauma.
- After blood transfusion reaction.
Pathophysiology
- In DIC there is inappropriate activation of the clotting system.
- This will lead to systemic or localized fibrin clot formation.
- Due to increased clotting, there is sludging and excessive bleeding because of the consumption of platelets + clotting factors.
- There is increased coagulation which overcomes the inhibitory mechanism.
- This will leads to thrombus formation at the site and in the microcirculation leading to the hemorrhagic syndrome.
- This hemorrhagic syndrome is called DIC, or defibrination syndrome or consumptive coagulopathy.
- The fibrinolytic system is activated breaks the clots + fibrin.
- Fibrinolysis leads to FDP (Fibrin degradation products).
- FDPs increase bleeding tendency.
- Intravascular clots lead to microvascular occlusion leads to injury to the organs.
- There may be hemolysis of RBCs by passing through these vessels.
- DIC may be:
- Acute DIC (Acute hemorrhagic DIC).
- Chronic DIC (Subacute chronic DIC).
Workup of a patient with DIC:
- The lab. finding of the DIC reflects direct or indirect excess of thrombin and plasmin generation.
- No single test is diagnostic.
- Indirect tests are the lake for thrombin action includes PT, APTT, and thrombin/reptilase clotting test.
- The confirmatory test is the demonstration of the fibrin deposition in the biopsy blood vessels which are involved.
- The following tests are advised to diagnose DIC
- Platelet count. There is thrombocytopenia.
- There is an increased plasma level of platelets specific protein (β-thromboglobulin).
- Platelet factor 4.
- Prothrombin time (PT).
- Partial thromboplastin time (PTT).
- Coagulation factor assay.
- Fibrinogen degradation products (FDP).
- Fibrinogen.
- d-dimer.
- Prothrombin fragments.
- The peripheral blood smear shows schistocytes.
- Platelet count. There is thrombocytopenia.
- Immediately perform the following test and that will diagnose the DIC.
- PT.
- PTT.
- Platelet count.
- Bleeding time
Causes of DIC:
- Bacterial Septicemia.
- Retention of a dead fetus.
- Amniotic fluid embolism.
- Liver diseases.
- malignant diseases.
- Extensive surgery on the liver or prostate.
- Heart bypass surgery.
- Extensive trauma.
- Severe burns.
- Transfusion reaction.
Clinical conditions associated with DIC:
Due to Thromboplastin release – Factor VII activation:
- Placental abruption.
- Sepsis.
- Promyelocytic leukemia.
- Retained dead fetus syndrome.
- Amniotic fluid embolus.
- Cardiopulmonary bypass surgery.
- Acute intravascular hemolysis.
- Adenocarcinoma (mucin-producing).
- Trauma.
Due to Factor X / II activation:
- Acute pancreatitis.
- Snake venom.
- Fat emboli syndrome.
- Liver diseases.
Due to endothelial cells damage – Factor XII activation:
- Liver diseases.
- Intravascular hemolysis.
- Immune complex diseases.
- Vasculitis.
- Burns.
- Anoxia.
- Acidosis.
- Heatstroke.
The table shows the findings of the various test in DIC:
Tests |
Outcome |
---|---|
Bleeding time | Increased |
Platelet count | Decreased |
Partial thromboplastin time | Increased |
Prothrombin time | Increased |
FDPs | Increased |
Fibrinogen | Decreased |
d-Dimer | Increased |
Prothrombin fragments | Increased |
Coagulation factors | Decreased I, II, V, VIII, X, XIII |
Peripheral smear | Damaged RBCs |
Laboratory diagnosis of Acute DIC:
Lab Test | DIC |
PT | usually prolonged |
PTT | Usually prolonged |
Fibrinogen contents | usually decreased |
Confirmatory test | |
FDP | Positive more than 40 µg/mL |
D-Dimer | Positive |
Table showing different between acute and Chronic DIC:
Lab Tests |
Acute DIC |
Chronic DIC |
PT | prolonged | normal |
PTT | prolonged | normal |
Fibrinogen | usually decreased | usually normal |
D-dimer | positive | positive |
FDP | positive >40 µg/mL | positive <40 µg/mL |
Normal Values Seen in the normal person:
-
Platelets are normal.
-
PT and PTT normal.
-
FDPs are negative.
Treatment
Treatment is two folds:
- Removal of the underlying pathologic cause.
- Maintain the blood volume and hemostatic function.
- There is a transfusion of the packed red blood cells.
- Give fresh frozen plasma.
- Give platelets concentrate.