Blood Cancer-I

Disseminated Intravascular Coagulation
What is Disseminated Intravascular Coagulation

Disseminated intravascular coagulation (DIC) is a disorder that affects the blood clotting cascade. This disorder occurs when your body's clotting mechanisms are activated inappropriately. DIC can occur in the short or long term, and is the end complication of a variety of diseases such as cancers and some infections. Clots form throughout the whole body, instead of localizing only to the site of injury. Eventually, all the blood clotting factors are used up and unavailable to be used when needed at actual sites of injury. In the image on the right severe bleeding has occured in an infant, leading to gangrene within the affected limb.

Who gets Disseminated Intravascular Coagulation?

Disseminated intravascular coagulation often presents with a subacute thrombotic picture in cancer patients, and is associated with high mortality rates when this acutely develops into the haemorrhagic form.

Disseminated intravascular coagulation occurs in 7-10% of patients with malignant disease. Adenocarcinomas and leukaemias are the most common cancer associations.

Predisposing Factors

About 50% of individuals with disseminated intravascular coagulation are patients with complications from pregnancy. Widespread infection and trauma are responsible for the majority of the remaining cases.

There are many causes of disseminated intravascular coagulation. These can be classified as acute or chronic, systemic or localized. The disorder may be the result of single or multiple conditions.

Acute DIC:

Infectious:

• Bacterial (eg: gram-negative infections, meningococcal disease)
  
• Viral (eg, HIV,
  cytomegalovirus [CMV], varicella)
  
• Fungal (eg, histoplasma)
  
• Parasitic (eg, malaria )

Malignant disease:

• Those originating in cells of the bloodstream (eg, acute myelocytic leukemias)
  
• Spread of cancers

Obstetric:

• Placental abruption (early separation of a normal placenta from the wall of the uterus
  
• Eclampsia (a serious complication of pregnancy characterized by convulsions.)

Trauma

Burns

Surgery

Acute liver failure

Snake bites

Transfusion reactions of blood

Chronic DIC:

Malignancies

• Leukaemia

Obstetric:

• Retained products of conception (eg - dead fetus, post miscarriage).

Vascular:

• Rheumatoid arthritis

Inflammatory:

• Ulcerative colitis,
  Crohn's disease (inflammatory conditions affecting the bowels).

Progression

Disseminated intravascular coagulation begins with over-activation of your body's coagulation system and excessive clotting. The excessive clotting is usually stimulated by a substance that enters the blood, with possible causes as listed above. As the clotting factors and platelets are consumed, there are less clotting factors available to be used at real sites of bleeding and excessive bleeding occurs. The results of this process (ie. abnormal small clots (microthrombi) and/or bleeding) are found in many organs and tissues. Significant changes may occur in some of your body's organs such as the kidney, lungs, brain, adrenals or placenta.

Probable Outcomes

The prognosis for disseminated intravascular coagulation varies according to each individual patient. It depends on the cause of your disseminated intravascular coagulation.

How Will Disseminated Intravascular Coagulation Affect Me?

If you are affected by disseminated intravascular coagulation, some of the following symptoms may be experienced;

Symptoms of infection - fevers, cough, shortness of breath, pain, rash, behaviour changes, sick contacts and recent travel.

If you are young and affected by disseminated intravascular coagulation, a birth history may be relevant -

• Events occurring just before, around and after birth - ie. course of pregnancy, prenatal testing, any neonatal illnesses may be important.
  
• Risk factors for infection around the time of your birth (fever in your mother, premature rupture of the membranes, your mother's status for a particular bacteria called group B streptococcus and antibiotics given around the time of birth).

Depending on your condition, age and many other factors, your doctor may ask about symptoms such as -

• Abnormal or increased bruising
  
• Lethargy (tiredness)
  
• Recent illness, infections.
  
• Loss of weight
  
• Drug use
  
• Pregnancy history
  
• Family history suggestive of an inherited clotting disorder or cancers
  
• Ongoing medical problems including; cancers, problems with blood vessels and inherited or acquired problems affecting the immune system.

Clinical Examination

When your doctor examines you, he or she may find the following signs. There may be no bleeding at all, to widespread bleeding at different sites of the body.

• Bleeding may occur from the mouth, nose, sites of injections, or from virtually any site.
  
• There may be widespread bruising.
  
• Abnormal clots may block off vessels to vital organs. Any organ may be involved but the skin, brain and kidney are most commonly affected. Respiratory symptoms such as shortness of breath or extreme respiratory difficulty may occur if the lungs are involved.
  
• Neurologic signs such as convulsions (due to abnormal electrical activity in the brain causing things such as abnormal movements, spasms, or changes in behaviour) and coma (a state of unconsciousness) may be present.

How is Disseminated Intravascular Coagulation Diagnosed?

The doctor may decide to do some of the following tests, to help determine the reason for and the severity of your disseminated intravascular coagulation.

In severe cases with increased bleeding, some of these tests may be performed:

• Blood film - this is a smear of the blood taken,which may show broken, fragmented red blood cells.
  
• Decreased platelets (platelets are a type of blood cell which have a key role in normal blood clotting. They clump together during clotting processes, to plug holes in damaged blood vessels).
  
• Increased prothrombin time (PT) - this test measures the clotting time of plasma (the liquid portion of the blood).
  
• Increased activated partial thromboplastin time (APTT) - this measures the time it takes for clots to form by various pathways in the body.
  
• High levels of fibrin degredation products (FDPs). These are proteins that are produced when clots are broken up by the body.
  
• Decreased fibrinogen. (A protein produced by the liver which helps stop bleeding by helping blood clots form).
  
• Decreased amounts of factors that help the blood clot;
  - Factors V, VIII, X, XIII
  - Protein C.

In mild cases without bleeding, the following test results may be present:

Increased synthesis of clotting factors and platelets may result in a normal PT, APTT, TT and platelet counts, although FDPs will be raised.

There is no single diagnostic test for disseminated intravascular coagulation. This condition is suggested by the following combination: a clinical picture consistent with disseminated intravascular coagulation, low levels of platelets, prolonged PT and APTT, and presence of FDPs.

How is Disseminated Intravascular Coagulation treated?

• If you are affected by disseminated intravascular coagulation, the doctor's first step is to treat the underlying cause of your disease, where possible. For example - if infection is the underlying cause, you may be given appropriate antibiotics.
  
• You may also be given supportive treatment like fluids and your urine output monitored with a urinary catheter.
  
• The next step is to replace missing blood components. If your platelet levels are low, platelet transfusions are appropriate. If plasma coagulation factors are decreased, they may be replaced with fresh frozen plasma. If fibrinogen levels are low, the doctor might consider transfusion with cryoprecipitate, which is a substance rich in fibrinogen.
  
• Doctors might consider heparin therapy in your treatment, which is a controversial issue. Heparin helps stop clotting, working by stopping enzymes that potentiate clotting. However, in some patients, bleeding can be accelerated.
  
• Thus heparin therapy is probably is best reserved for patients with evidence of ischemia (insufficient blood supply) of the digits and cyanosis.
  
• Surgical treatment is limited to treating certain underlying causes - eg. removal of a cancer.

Disseminated Intravascular Coagulation References

1. Furlong MA, Furlong BR. Disseminated Intravascular Coagulation 2005 E-medicine [serial online]. 2005 [cited 24th April 2006]. Available from URL: http://www.emedicine.com/emerg/topic150.htm
   
2. Longmore M, Wilkinson I, Torok E. Oxford Handbook of clinical Medicine. New York; Oxford University Press, 2001.
   
3. Kumar V, Abbas A K & Fausto N. Robbins & Cotran Pathologic Basis of Disease. China: Elseiver Saunders; 2005.
   
4. Kumar P, Clark M. Clinical Medicine United Kingdom: WB Saunders; 2002.
   
   
   

   Drugs/Products Used in the Treatment of This Disease:

   • Heparin Injection BP (DBL)
     (Heparin sodium)