What Happens in Disseminated Intravascular Coagulation (DIC)?

Medically reviewed by Gagandeep Brar, MD

Disseminated intravascular coagulation (DIC) is a potentially life-threatening condition that develops when the delicate balance of factors involved in blood clotting is disrupted. As a result, a person with DIC easily clots, bleeds, or both.

DIC does not develop in isolation but is triggered by an underlying health issue, such as a severe infection, trauma, or cancer. Its presence is highest in critically ill people who are often hospitalized in the intensive care unit (ICU).

This article explores what it means to have disseminated intravascular coagulation, including how it develops and its symptoms. It will also review the diagnosis and treatment of DIC.

Why Does Blood Overclot in Disseminated Intravascular Coagulation?

When a blood vessel in the body is injured, proteins and platelets (disc-shaped cell fragments) work harmoniously to "plug" the wound site while simultaneously preventing blood loss.

The body's ability to form this plug, or blood clot, is twofold, relying on both procoagulant (pro-clot) components and anticoagulant (anti-clot) components.

The procoagulant components create the blood clot, whereas the anticoagulant components limit the clot formation to prevent thrombosis.

What Is Thrombosis?

Thrombosis is when a clot obstructs the inside of the blood vessel. This blockage restricts blood flow to organs like the liver, brain, or kidneys.

In DIC, the procoagulant pathways are activated, while the anticoagulant pathways are simultaneously impaired.

Since the procoagulant and anticoagulant components are not in sync, blood clots form in small- to medium-size blood vessels throughout the body. These widespread clots impair blood flow, contributing to organ failure.

Excessive bleeding may also occur in DIC, especially if the condition progresses rapidly. Bleeding is due to the depletion or consumption of platelets and proteins used initially to help the blood clot form.

Stages of DIC

DIC occurs in the following two stages:

• Stage 1: The thrombotic phase (when blood clots obstruct small vessels)

• Stage 2: The bleeding phase (when clotting factors are all used up)

A person with DIC may experience one or both stages.

What Causes Disseminated Intravascular Coagulation?

DIC does not occur on its own. An underlying health condition always triggers it. DIC's common causes—sometimes referred to as risk factors—are sepsis and cancer.

Sepsis occurs when an infection triggers a severe whole-body reaction. The infection can be a virus, bacterium, fungus, or parasite.

DIC can also develop in individuals with cancer, including solid cancers (e.g., lung or pancreatic cancer) and blood cancers (leukemia), especially acute promyelocytic leukemia.

Other possible causes or risk factors for DIC include:

• Pregnancy and childbirth complications, including HELLP syndrome (hemolysis, elevated liver enzymes, and low platelet count), placental abruption (placenta separates from the uterine wall before birth), or amniotic fluid embolism (rare, life-threatening condition during delivery or soon afterward)

• Severe trauma, especially to the brain

• Major surgery, especially involving the biliary system (e.g., liver, gallbladder, and pancreas)

• Aortic aneurysm (a bulging of the main artery that transports blood away from your heart)
  

Emergency Disseminated Intravascular Coagulation Symptoms

The symptoms or manifestations of DIC include blood clots and bleeding, and their severity depends partially on whether the DIC is acute versus chronic.

Acute DIC is more severe and develops very quickly, over hours to days. People with acute DIC are usually very sick and in the hospital.

Chronic DIC develops slowly over weeks to months and can often be managed by a hematologist (doctor specializing in blood diseases) as an outpatient once the condition is stabilized.

Blood clotting and bleeding can occur in both acute and chronic DIC, although acute DIC is more likely to present with profuse bleeding due to the rapid consumption of clotting factors.

Seek Emergency Medical Attention

Go to the nearest emergency room or call 911 if you develop uncontrollable bleeding or potential symptoms of a blood clot like chest pain, extremity swelling, trouble breathing, or confusion.

Blood Clots

The symptoms of blood clotting depend on the site(s) of the blockage. As an example, if a blood clot forms in the leg's deep veins—called deep vein thrombosis, or DVT—leg swelling, warmth, redness, or tenderness develops.

Likewise, trouble breathing and chest pain can occur if a blood clot forms in the chest vessels near the lung or heart.

Thrombosis in small blood vessels that supply the liver or kidney may result in liver/kidney damage or failure. A stroke may occur if a blood clot prevents blood from reaching the brain.

Learn More: Signs and Symptoms of a Blood Clot

Bleeding

Symptoms of bleeding in DIC include:

• Oozing from the gums or sites on the body where IV (intravenous) needles, catheters (e.g., urinary), or drains are placed

• Blood in the stool from stomach or intestinal bleeding

• Blood in the urine from bleeding in the kidney or bladder

• Headache, vision changes, or seizures from bleeding in the brain

• Large bruises or hematomas (tender collections of blood underneath the skin)

• Widespread skin rash of tiny red/purple dots (petechiae) or purple patches (purpura)
  

Related: Telling the Difference Between Petechiae and Purpura

Labs That Confirm Disseminated Intravascular Coagulation

There is no single test that can diagnose DIC. Instead, healthcare providers consider the results of several blood tests and the patient's overall clinical picture.

DIC diagnostic blood tests include:

• A complete blood count (CBC) shows the number of cells in your bloodstream, including platelets.

• Prothrombin (PT) and partial thromboplastin time (PTT) measure the time it takes for blood to clot.

• Fibrinogen is the main protein found in blood clots.

• D-dimer is a degradation product of a dissolving clot.

In DIC, the platelet count in DIC is typically reduced, and the PT and PTT tests are prolonged. Also, fibrinogen is usually low (as it's depleted from excessive clotting), and D-dimer levels are elevated.

Disseminated Intravascular Coagulation Treatment

The cornerstone for treating DIC involves addressing the underlying cause.

For example, suppose a person has bacterial sepsis and resultant DIC. In that case, treatment is focused on killing the infection with antibiotics and providing support measures.

Such measures might include:

• Administering intravenous fluids, blood, or medications to ensure adequate blood circulation to the person's organs.

• Sedating a person and placing them on a ventilator (breathing machine).

Other treatments might include chemotherapy and surgery for DIC related to cancer or baby delivery in cases of obstetric problems.

Secondly, treatments geared toward DIC are implemented. Depending on the clinical scenario, these might include:

• Platelet transfusions are given if a person has severe bleeding and/or low platelet counts.

• Clotting factor replacement therapy is given for severe bleeding in patients with high PT/PTT or low fibrinogen levels.

• Heparin (blood thinner) is sometimes given if there is evidence of organ failure related to blood clotting.

Factors That Affect DIC Treatment Success

Scientific research suggests that DIC treatment success depends predominantly on how promptly the condition is diagnosed and the therapeutic strategies used to manage the condition.

Specific factors, like the platelet count or fibrinogen level, the severity of the DIC, and the underlying cause (e.g., sepsis, trauma, cancer), may also help predict treatment success, although more investigation is required.

What Is the Mortality (Death) Rate for DIC?

In 2017, the 28-day mortality rate for critically ill people with DIC was found to be 36%, a slight decline from nearly 42% in 2010. Experts suspect the decline stems from advances in DIC therapies and changes in DIC-related care strategies.

Related: Morbidity vs. Mortality: What's the Difference?

Ongoing DIC Treatment and Monitoring

Once the underlying health condition is treated, DIC can spontaneously resolve, sometimes within hours. That said, in many cases, DIC persists, and it's not necessarily clear why.

Ongoing DIC requires close laboratory monitoring and care to restore platelet or clotting factor deficiencies or calm overactive clotting.

If you have been diagnosed with ongoing or chronic DIC, please take your medications as prescribed, report any new symptoms or side effects to your healthcare provider, and follow through with your blood tests.

Summary

Disseminated intravascular coagulation (DIC) is a serious condition associated with widespread blood clotting and/or bleeding. The condition is triggered by an underlying health issue, namely sepsis, cancer, trauma, or obstetric complications. DIC may occur suddenly, usually in critically ill people, or come on gradually over weeks to months.

Treatment aims to fix the root cause and restore the body's normal blood-clotting pathways. The latter may be achieved by administering platelet transfusions or clotting factor replacement therapies.