Disseminated intravascular coagulation (DIC)

Disseminated intravascular coagulation

DESCRIPTION: 

 Disseminated intravascular coagulation is a serious disorder in which the proteins that control blood clotting are abnormally active, DIC may cause tissue ischemia from occlusive microthrombi and bleeding from both the consumption of platelets and coagulation factors.

 CAUSE ANF RISCK FACTOR:

Normally, when you are injured, certain proteins are turned on and travel to the injury site to help stop bleeding. However, in persons with DIC, these proteins are abnormally active. Small blood clots form throughout the body. Overtime, the clotting proteins become used up and are unavailable during times of real injury

This disorder can result in clots or, more often, bleeding. Bleeding can be severe

 Risk factors for DIC include:

1-    Blood transfusion reaction

2-    Cancer, including leukemia

3-    Infection in the blood by bacteria or fungus

4-    Pregnancy complications such as retained placenta after delivery

5-    Recent surgery or anesthesia

6-    Sepsis

7-    Severe liver disease

8-    Severe tissue injury as in burns and head injury

Clinical manifestations:

The manifestations of DIC depend on the magnitude and rate of exposure to the DIC trigger. For example, the dramatic cases of “acute” DIC, characterized by severe bleeding due to excessive consumption of hemostatic components, may develop when blood is exposed to large amounts of tissue factor over a brief period of time. Alternatively, “chronic” DIC develops when blood is continuously or intermittently exposed to small amounts of tissue factor.

1. Bleeding

Acute DIC is hemorrhage into the skin at multiple sites. Petechiae, ecchymosis, and oozing from veni-punctures, arterial lines, catheters, and injured tissues are common. Bleeding may also occur on mucosal surfaces. Hemorrhage may be life-threatening, with massive bleeding into the gastrointestinal, lungs, central nervous system, or orbit. Patients with chronic DIC usually exhibit minor skin and mucosal bleeding.

2. Thromboembolism:

Extensive organ dysfunction can result from microvascular thrombi or from venous or arterial thromboembolism. For example, involvement of the skin can cause hemorrhage, necrosis, and gangrene; involvement of the lungs can cause acute respiratory distress syndrome, hypoxemia, edema, hemorrhage.

3.Circulatory disturbance lead to shock

Both the diseases underlying DIC and DIC itself can cause shock. For example, septicemia or excessive blood loss to trauma or to obstetric complications can by themselves cause shock.

Laboratory test:

1.  Basic blood examinations

-          Platelet count: thrombocytopenia is an early and consistent sign of DIC is low.

2.  The coagulation defect

1-    Prothrombin time (PT) - )(high Pt 11-16 seconds)

2-    Partial thromboplastin time (PTT) - high (Ptt25-39 seconds)

3-    Fibrinogen concentration: The plasma levels of fibrinogen usually are significantly depressed.

4-    We need to international normal ratio (INR) =   pt test / pt normal.

Complications

1-    Severe bleeding

2-    Stroke

3-    Lack of blood flow to arms, legs, or organs

4-    Kidney failure.

5-    Liver failure.

6-    Myocardial infarction.

Treatment:

1.  Management of underlying disorders

The survival of patients with DIC depends on vigorous treatment of the underlying disorders and curtailing the triggers of blood coagulation. For example, intensive antibiotic treatment in patients with gram-negative bacteremia, hysterectomy in patients with abruptio placenta, resection of an aortic aneurysm, and debridement of crushed tissues are the most essential steps in the management of such patients.

2.  Antiplatelet drugs

1-    Dipyridamole 200-400mg/d intravenous drip.

2-    Aspirin 0.9-1.2g/d.

3-    Heparin.