Disseminated intravascular coagulation: Clinical sciences

Disseminated intravascular coagulation, or DIC for short, occurs when a trigger over-activates the coagulation and fibrinolytic cascades, leading to widespread thrombosis and organ ischemia. As DIC progresses, excessive bleeding occurs due to the consumption of platelets and coagulation factors. Based on the timing of onset, clinical presentation, and lab findings, DIC can be classified as acute and chronic.

Now, if your patient presents with chief concerns suggesting DIC, you should first perform an ABCDE assessment to determine if the patient is unstable or stable.

If the patient is unstable, stabilize the airway, breathing, and circulation, obtain IV access, and give IV fluids. Next, put your patient on continuous vital sign monitoring, including blood pressure, heart rate, and pulse oximetry. Finally, if your patient is hypotensive, add vasopressors and if their saturation is low, don’t forget to provide supplemental oxygen to keep saturation above 90 percent.

Now, once you stabilize your patient, obtain a focused history and physical examination. Your patient is likely to report an acute onset of bleeding; and in some cases, they might report symptoms of thrombosis, such as sudden-onset dyspnea or limb pain. The sudden onset of dyspnea should make you suspect pulmonary embolism, while limb pain could be associated with limb ischemia due to thrombosis.

Next, history will typically reveal a trigger like sepsis, trauma, malignancy, or obstetric complications, such as placental abruption and amniotic fluid embolism.

The physical exam will reveal petechiae, purpura, and ecchymosis; and possibly evidence of thrombosis, such as limb swelling and redness. Additionally, you might find signs of underlying illness like fever, hypotension, and tachycardia; or findings consistent with organ dysfunction, like respiratory distress, jaundice, and decreased urine output.

With these findings, you should suspect acute DIC, so your next step is to order labs, including CBC, PT, aPTT, fibrinogen, D-dimer, and peripheral smear.

Massive formation of blood clots throughout the body depletes thrombocytes and clotting factors, so the labs will typically reveal thrombocytopenia with a platelet count of less than 150,000 cells/L and a prolonged PT and aPTT.

Additionally, during blood clot formation, fibrinogen is converted into fibrin, so your patient might have low fibrinogen levels. But, keep in mind that fibrinogen is also an acute phase reactant so in a patient with DIC, fibrinogen could be elevated despite the ongoing blood clot formation.

Simultaneously, the body will try to break down blood clots, so you will typically find elevated D-dimer levels, which is a degradation product of fibrin. Finally, the peripheral smear may reveal fragmented red blood cells, known as schistocytes. With these findings, you can diagnose acute DIC!

Now, here’s a clinical pearl! In acute DIC, the rapid consumption of platelets and coagulation factors outpaces the body’s ability to compensate with new production, so bleeding generally predominates over thrombosis. So, while it is possible for an acute DIC patient to be hemodynamically stable, the overwhelming bleeding and clotting, known as decompensated DIC, is why these patients are typically unstable.

Now, once you diagnose acute DIC, the most important step in management is treatment of the underlying cause to remove the trigger initiating the process. For example, if the underlying cause of DIC is sepsis, be sure to start your patient on broad-spectrum antibiotics. Additionally, these patients often require supportive treatment, like hemodynamic and ventilatory support.

Next, if there’s evidence of thrombosis, consider anticoagulation therapy with unfractionated heparin or low molecular weight heparin. Finally, if there’s severe acute bleeding or your patient requires invasive procedures, you might need to transfuse blood components. Moreover, if the hemoglobin is less than 7 mg/dL, transfuse packed red blood cells, and if the platelets drop below 50,000 cells/L, give platelets.