Disseminated Intravascular Coagulation

Question 1

Define DIC

Answer 1

Activation of coagulation pathways
-  intravascular thrombosis -> ischaemia ->
multi-organ failure
- depletion of platelets and coagulation
factors -> spontaneous generalised
bleeding in at least 3 unrelated sites

Acute
Endothelial damage -> release of tissue factor ->
thrombin generation -> depletion of platelets and
coagulation factors

Chronic
Slower process with compensatory mechanisms
reducing likelihood of bleeding ->
hypercoagulable state -> thrombosis

Question 2

What are the causes/risk factors of DIC?

Answer 2

DIC is triggered by conditions causing systemic activation of coagulation
• Sepsis/burns
• Malignancy e.g. APML
• Obstetric complications e.g. severe pre-eclampsia, placental abruption
• Severe trauma/organ destruction
• Vascular disorders e.g. aortic aneurysm, haemangioma
• Severe toxic/immunological reactions e.g. haemolytic transfusion reaction, snake bite

Question 3

What are the symptoms of DIC?

Answer 3

• Bleeding
• Confusion
• Dyspnoea

Question 4

What are the signs of DIC?

Answer 4

• Fever
• Hypotension
• Tachycardia
• Petechiae
• Purpura
• Ecchymoses
• Epistaxis
• Mucosal bleeding
• Overt haemorrhage
• Respiratory distress
• Oliguria (renal failure)
• Infarction or gangrene

Question 5

What investigations are carried out for DIC?

Answer 5

• Platelet Count - low; thrombocytopaenia due to excessive consumption.
• Hb - low; anaemia due to internal bleeding secondary to DIC.
• Clotting - prolonged APTT, PT and TT.
• Fibrinogen - low
• FDP or D-Dimers - positive/ High
• Peripheral Blood Film - red blood cell fragments (schistocytes) if fibrin deposition leads to MAHA