Disseminated Intravascular Coagulation (DIC) Flashcards
Define Disseminated Intravascular Coagulation (DIC)?
A disorder of the clotting cascade that can complicate a serious illness
What are the two forms that DIC can occur in?
Acute overt form
Chronic non-overt form
What is the Acute Overt Form?
Where there is bleeding and depletion of platelets and clotting factors
What is the Chronic non-overt form?
Where thromboembolism is accompanied by generalised activation of the coagulation system
What are some of the causes of DIC?
Infection Obstetric Complications Malignancy Severe Trauma or surgery Others
What are some of the particular causes of infection?
Gram-negative sepsis
What are some of the obstetric complications of DIC?
Missed miscarriage (when the foetus dies but the body doesn’t realise it and the placenta continues to release hormones
Severe pre-eclampsia
Placental abruption (separation of the placenta from the wall of the uterus during pregnancy)
Amniotic Emboli
What are some of the malignant causes of DIC?
Acute promyelocytic leukaemia - acute DIC
Lung, breast and GI malignancy - Chronic DIC
What are some of the rarer causes of DIC?
Haemolytic transfusion reaction Burns Severe liver disease Aortic aneurysms Haemangiomas
What is the pathophysiology for Acute DIC?
Endothelial damage and the release of granulocyte/ macrophage procoagulant substances (e.g. tissue factor) lead to activation of coagulation
This leads to explosive thrombin generation, which depletes clotting factors and platelets, whilst also activating the fibrinolytic system
This leads to bleeding in the subcutaneous tissues, skin and mucous membranes
Occlusion of blood vessels by fibrin in the microcirculation leads to microangiopathic haemolytic anaemia and ischaemic organ damage
What is the pathophysiology of Chronic DIC?
Identical process to acute DI
Happens at a slower rate with time for compensatory responses
The compensatory responses diminish the likelihood of bleeding but give rise to hypercoagulable states and thrombosis can occur
What is the epidemiology of DIC?
Seen in any severely ill patient
What are the presenting symptoms of DIC?
The patients will tend to be severely unwell with symptoms of the underlying disease
Confusion
Dyspnoea
Evidence of bleeding
What are the general signs of DIC on physical examination?
Signs of underlying disease
Fever
Evidence of shock (hypotension, tachycardia)
What are the signs of Acute DIC on physical examination?
Petechiae, purpura, ecchymoses Epistaxis Mucosal Bleeding Overt haemorrhage Signs of end organ damage Respiratory Distress Oliguria due to renal failure
