DIC x Flashcards
causes of DIC?
Shock
Sepsis/severe infection
Major trauma or burns
===^most common^====
Malignancies -
Acute promyelocytic leukaemia (APML) is strongly associated with DIC
Severe immune-mediated reactions: such as acute haemolytic transfusion reactions due to mismatched ABO antigens, organ = MOST COMMON
transplant rejection and bites
Severe organ dysfunction: including acute hepatic failure esp hepatic cirrhosis) and severe acute pancreatitis.
Obstetric emergencies: including eclampsia, HELLP (haemolysis, elevated liver enzymes and low platelets) syndrome, placental abruption, intrauterine death and amniotic fluid embolism.
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clinical features of DIC?
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
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 dry gangrene for instance of the digits
Hepatic dysfunction: jaundice
ARDS: dyspnea, rales
Pulmonary thromboembolism: dyspnea, chest pain, hemoptysis
Deep vein thrombosis: lower limb edema
Neurological dysfunction: altered mental status, stroke
Purpura fulminans: DIC with extensive skin necrosis
Waterhouse Friderichsen syndrome: adrenal infarcts → adrenal insufficiency
Signs of shock
= Oliguria, hypotension and/or tachycardia: signs of circulatory collapse, which is associated with DIC
New confusion or disorientation: a sign of microvascular thrombosis affecting cerebral perfusion
what are the investigations you order for DIC
no single investigation that can ‘prove’ DIC. The diagnosis is made based on both clinical and laboratory features. Tests also need repeating regularly as the condition evolves over time
history taking of past medical history
Symptoms of infection, malignancy (night sweat , weight loss , anemia , lymphadenopathy)
organ failure
and bleeding
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ISTH scoring system
utilises the platelet count, D-dimer value, prothrombin time and fibrinogen levels
used for patients in whom there is clinical evidence
FBC - thrombocytopenia
PT - measure of extinsic and common pahway and it is PROLONGED
APTT - measures the intrinsic pathway - and it is PROLONGED
clauss fibrinogen - typically decreased
d-dimer or FDP - high
All other blood tests and imaging studies will depend on the underlying cause. For instance, in cases of sepsis blood cultures and serum lactate should be requested
dd of DIC ?
Acute hepatic failure is the most common differential diagnosis and also a well-recognised cause of DIC, which can make distinguishing the two conditions challenging.
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vitamin K deficiency there will be signs of bleeding but no signs or symptoms of thrombosis. The PT will be prolonged and sometimes the APTT as well. D-dimer will be normal in contrast to DIC.
The best test is to give a dose of intravenous vitamin K. In vitamin K deficiency clotting results will correct within six hours.
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hELLP Syndrome
HELLP syndrome usually occurs after 28-weeks’ gestation and is associated with pre-eclampsia. The key features are hypertension, deranged LFTs and thrombocytopenia.
HELLP syndrome is also a recognised cause of DIC.
D-dimer is often elevated in pregnancy so is not a particularly useful test in this context. The FBC will show low platelets and possibly anaemia (due to haemolysis)
noral PT , aPTT and fibrinogen
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Idiopathic purpura fulminans
Idiopathic purpura fulminans (IPF) is a condition characterised by well-demarcated cutaneous purpuric lesions.
It is usually associated with sepsis. D-dimer levels are often normal, helping to distinguish it from DIC.
platlets are decreased
PT - normal
aptt - normal
===== heparin use PT - normal APTT- increased platelts - normal
thrombocytopenia
pt- normal
aptt - normal
platelts - decreased
platelet defects
PT - normal
aptt - normal
platelets - normal
viot k deficiency pt- increased aptt 0 increased platelets - normal .
what is the management of DIC ?
two stages: treatment of the underlying disorder, which stops the triggering process, and supportive treatment to restore normal coagulation
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Platelet transfusions should be considered if the patient is bleeding. The platelet count should be maintained >50 x 109/L in the presence of bleeding.
In bleeding patients or going to undergo invasive procedure with a PT or aPTT > 1.5 times the normal value fresh frozen plasma given
Concentrated solutions of clotting factors may also be considered such as prothrombin complex concentrate, or specific factor infusions.
pRBCs: indicated for patients with active bleeding or Hb ≤ 7 gr/dL
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If there is severely low fibrinogen <150mg/dl then transfusions of cryoprecipitate or fibrinogen concentrate should be considered.
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if thrombosis is a prominent feature (like in organ failure) , then therapeutic doses of heparin should be considered. If there is co-existing high risk of bleeding, then unfractionated heparin can be used since this has a significantly shorter half-life and is more readily reversible than low molecular weight heparin
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other patients who are non-bleeding, prophylactic doses of heparin are recommended to protect against VTE. This might seem counter-intuitive since these patients remain at high risk of bleeding, but they are also at risk of venous thromboembolism so will require thromboprophylaxis
complication of DIC?
Multi-organ failure
Life-threatening haemorrhage
Cardiac tamponade - bleeding into the pericardial space resulting in Beck’s triad
Intracranial haemorrhage
