Disseminated intravascular coagulation (DIC)

Question 1

Define disseminated intravascular coagulation (DIC).

Answer 1

DIC is an acquired syndrome characterised by activation of coagulation pathways, resulting in formation of intravascular thrombi and depletion of platelets and coagulation factors.

Thrombi may lead to vascular obstruction/ischaemia and multi-organ failure. Spontaneous bleeding may occur. Generalised bleeding, evidenced by at least 3 unrelated sites, is highly suggestive of DIC.

Question 2

Explain the aetiology/risk factors of disseminated intravascular coagulation (DIC).

Answer 2

Disease states that trigger systemic activation of coagulation may lead to DIC. Causes include:

• Sepsis/severe infection, major trauma or burns
• Some malignancies (acute myelocytic leukemia or metastatic mucin-secreting adenocarcinoma)
• Obstetric disorders (amniotic fluid embolism, eclampsia, abruptio placentae, retained dead fetus syndrome)
• Severe organ destruction or failure (severe pancreatitis, acute hepatic failure)
• Vascular disorders (Kasabach-Merritt syndrome or giant haemangiomas, large aortic aneurysms)
• Severe toxic or immunological reactions (blood transfusion reaction or haemolytic reactions, organ transplant rejection, snake bite).

Question 3

Summarise the epidemiology of disseminated intravascular coagulation (DIC).

Answer 3

Many conditions can cause DIC; therefore, the overall incidence is difficult to determine. Age and sex are not good predictors. Mortality is high. For instance, the presence of DIC in patients with major trauma will result in a significant increase in overall mortality.

Question 4

Recognise the presenting symptoms of disseminated intravascular coagulation (DIC). Recognise the signs of disseminated intravascular coagulation (DIC) on physical examination.

Answer 4

Oliguria
Hypotension
Tachycardia
Purpura fulminans, gangrene, or acral cyanosis
Delirium or coma
Petechiae, ecchymosis, oozing, or haematuria

Question 5

Identify appropriate investigations for disseminated intravascular coagulation (DIC) and interpret the results.

Answer 5

Platelet count
Prothrombin time (PT)
Fibrinogen
D-dimer/fibrin degradation products
Activated partial thromboplastin time (aPTT)
Imaging studies or other tests