DISSEMINATED INTRAVASCULAR COAGULATION
Disseminated intravascular coagulation is an extreme complication of numerous already life-threatening conditions leading to the deregulation of the body’s natural mechanisms of blood clotting and blood clot dissolving. In other words, a very sick patient begins both bleeding abnormally and clotting abnormally at the same time leading to disaster and frequently to death. DIC is a disease of the blood.
SETTING THE SCENE FOR DIC
The patient must already have a serious problem before DIC sets in. Typical conditions that are associated with DIC include those involving dying internal tissue, widespread inflammation, red blood cell destruction, poor circulation, particulate matter in the bloodstream, or loss of blood vessel integrity.
DIC is primarily a canine problem but can occur in the cat in rare conditions.
In the normal body, there are small bleeds occurring regularly as we bump into things or cut ourselves. Blood clots patch these small blood vessel tears up and as healing takes place other blood mechanisms dissolve the old clots leaving scar tissue.
In DIC, the normal clotting mechanism is exaggerated. In the normal body, a substance called “antithrombin” (formerly called “antithrombin III”) is involved in dissolving old blood clots but in the event of exaggerated clotting, antithrombin becomes prematurely depleted. There are other anti-clotting proteins that are also depleted by the exaggerated clotting state. The result of this depletion is an excess of “fibrin,” the material of which blood clots are made.
Active proteins involved in the manufacture of fibrin stimulate the blood vessel cells to release inflammatory biochemicals (note: the patient very likely already started with a disease that involving widespread inflammation). Ultimately, there is both inappropriate clotting and bleeding at the same time.
The sooner DIC is recognized, the more likely the chance of a positive outcome. At first, there are no signs at all, just subtle blood test changes. It is important to for the medical staff to watch for these lab changes in patients known to have diseases associated with DIC.
There are several factors that go into the diagnosis of DIC and a patient need not have them all:
The absence of D-Dimer rules out DIC with 95% confidence.
Ultimately what all this clotting and bleeding comes down to is loss of blood flow to the tissues and treatment centers on restoring normal circulation. This means intravenous fluid administration is crucial to restore tissue perfusion. Often plasma transfusion are used to replenish consumed blood clotting proteins. Plasma is often incubated with an anticoagulant substance called “heparin” before it is administered. Heparin activates anti-thrombin, which, as mentioned, has been depleted in DIC.
The most significant factor in the treatment of DIC is removal of the original disease that predisposed the patient to DIC in the first place. If this can be achieved, it would be the best chance at resolving DIC.
Page posted: 3/25/09