Disseminated Intravascular Coagulopathy (DIC)

Sample

• Collect the blood for PT and PTT.
• Immediately do assay for clotting factors.

Purpose of the test (Indications)

1. To exclude the septicemia.
2. Amniotic fluid embolism.
3. Retention of the dead fetus.
4. Malignant neoplasia.
5. In liver cirrhosis.
6. Extensive surgery especially on the liver.
7. Severe burn.
8. Extensive trauma.
9. After blood transfusion reaction.

Pathophysiology

1. In DIC there is inappropriate activation of the clotting system.
2. This will lead to systemic or localized fibrin clot formation.
3. Due to increased clotting, there is sludging and excessive bleeding because of the consumption of platelets + clotting factors.
   1. There is increased coagulation which overcomes the inhibitory mechanism.
   2. This will leads to thrombus formation at the site and in the microcirculation leading to the hemorrhagic syndrome.
   3. This hemorrhagic syndrome is called DIC, or defibrination syndrome or consumptive coagulopathy.

4. The fibrinolytic system is activated breaks the clots + fibrin.
5. Fibrinolysis leads to FDP (Fibrin degradation products).
6. FDPs increase bleeding tendency.

7. Intravascular clots lead to microvascular occlusion leads to injury to the organs.
8. There may be hemolysis of RBCs by passing through these vessels.

9. DIC may be:
   1. Acute DIC (Acute hemorrhagic DIC).
   2. 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.

1. The following tests are advised to diagnose DIC
   1. Platelet count. There is thrombocytopenia.
      1. There is an increased plasma level of platelets specific protein (β-thromboglobulin).
      2. Platelet factor 4.
   2. Prothrombin time (PT).
   3. Partial thromboplastin time (PTT).
   4. Coagulation factor assay.
   5. Fibrinogen degradation products (FDP).
   6. Fibrinogen.
   7. d-dimer.
   8. Prothrombin fragments.
   9. The peripheral blood smear shows schistocytes.
2. Immediately perform the following test and that will diagnose the DIC.
   1. PT.
   2. PTT.
   3. Platelet count.
   4. Bleeding time

Causes of DIC:

1. Bacterial Septicemia.
2. Retention of a dead fetus.
3. Amniotic fluid embolism.
4. Liver diseases.
5. malignant diseases.
6. Extensive surgery on the liver or prostate.
7. Heart bypass surgery.
8. Extensive trauma.
9. Severe burns.
10. Transfusion reaction.

Clinical conditions associated with DIC:

Due to Thromboplastin release – Factor VII activation:

1. Placental abruption.
2. Sepsis.
3. Promyelocytic leukemia.
4. Retained dead fetus syndrome.
5. Amniotic fluid embolus.
6. Cardiopulmonary bypass surgery.
7. Acute intravascular hemolysis.
8. Adenocarcinoma (mucin-producing).
9. Trauma.

Due to Factor X / II activation:

1. Acute pancreatitis.
2. Snake venom.
3. Fat emboli syndrome.
4. Liver diseases.

Due to endothelial cells damage –  Factor XII activation:

1. Liver diseases.
2. Intravascular hemolysis.
3. Immune complex diseases.
4. Vasculitis.
5. Burns.
6. Anoxia.
7. Acidosis.
8. 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:

1. Removal of the underlying pathologic cause.
2. Maintain the blood volume and hemostatic function.
   1. There is a transfusion of the packed red blood cells.
   2. Give fresh frozen plasma.
   3. Give platelets concentrate.

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