Disseminated Intravascular Coagulation

Question 1

What is DIC?

Answer 1

Serious disorder occurring in response to an illness or disease process which results in dysregulated blood clotting.

Inappropriate activation of one or both systems leads to a paradoxical tendency to both bleeding and thrombosis simultaneously.

Question 2

Name causes of DIC

Answer 2

Shock
Sepsis
Trauma/Severe burns
Malignancy
Obstetric emergencies
Severe immune-medicated reactions (e.g acute haemolytic transfusion
reaction)
Severe organ dysfunction

Question 3

Briefly describe the pathophysiology of DIC?

Answer 3

Sepsis or trauma -> Systemic inflammatory response -> release of pro-inflammatory cytokines
OR
Up-regulation of pro-coagulant factors

-> activation of coagulation cascade -> microvascular thrombosis -> small thrombi -> multi-organ failure due to tissue ischaemia

-> reduction in circulating coag factors (consumptive coagulopathy) -> increased bleeding risk

Activation and aggregation of platelets-> thrombocytopenia -> bleeding risk

Question 4

What are the typical symptoms of DIC?

Answer 4

-Bleeding from unusual sites: ears, nose, gastrointestinal tract, genitourinary tract, respiratory tract or sites of venepuncture or cannulation.
-Bleeding from three unrelated sites is highly suggestive of DIC.
-Widespread or unexpected bruising without a history of trauma
-New confusion or disorientation: a sign of microvascular thrombosis affecting cerebral perfusion

Question 5

Signs of DIC on clinical examination:

Answer 5

-Signs of haemorrhage: bleeding from cannula sites/venepuncture sites, melaena, haematemesis, rectal bleeding, epistaxis, haemoptysis, haematuria

-Petechiae or purpura

-Livedo reticularis: a mottled lace-like patterning of the skin

-Purpura fulminans: widespread skin necrosis

-Localised infarction and gangrene e.g of the digits

-Confusion

-Oliguria, hypotension and/or tachycardia: signs of circulatory collapse, which is associated with DIC

Question 6

What are investigations can be done for DIC?

Answer 6

FBC - thrombocytopenia
Coag screen (PT and APTT) -likely to be prolonged
Clauss fibrinogen - decreased
D-dimer/fibren degradation products - raised

Question 7

What is ISTH scoring?

Answer 7

The international society of thrombosis and haemostasis (ISTH) has produced a scoring system, which aims to make the diagnosis of DIC more objective.

ISTH scoring based on platelet count, D-dimer value, PT and fibrinogen

only used for patients in whom there is clinical evidence of a precipitating cause

Question 8

Possible differential diagnoses for DIC

Answer 8

Acute hepatic failure
Vitamin K deficiency
HELLP syndrome
Idiopathic purport fulminans

Question 9

Management of DIC:

Answer 9

Treat underlying disorder
Supportive tx to restore normal coagulation
-platelet transfusion considered if pt bleeding (count should be maintained at >50x10^9/L)
-Fresh frozen plasma in bleeding pts with prolonged PT or APTT
-Cryoprecipitate or fibrinogen concentrate if severely low fibrinogen
-Therapeutic heparin if thrombosis prominent
-Non bleeding then prophylactic dose of heparin to protect against VTE

Question 10

Name some complications of DIC:

Answer 10

Multi-organ failure
Life-threatening haemorrhage
Cardiac tamponade
Haemothorax
Intracranial haemorrhage
Gangrene and loss of digits