Haematology Emergencies Flashcards
What is the pattern of disease prgression with sickle cell anaemia?
Periods of good health with intervening crises.
What are the different types of sickle cell crisis?
- Thrombotic
- Sequestration
- Acute chest syndrome
- Aplastic
- Haemolytic
What is sickle cell anaemia?
AR condition causing abnormal haemoglobin chains which are fragile and haemolyse, causing small vessel infarction
What is a thrombotic sickle cell crisis?
Vaso-occlusion of microcirculation by sickled red blood cells causing ischaemia. Large vessels can also be involved.
What is an aplastic sickle cell crisis?
A temporary cessation of erythropoiesis causing severe anaemia, usually precipitated by parvovirus B19 infection.
What is a sequestration sickle cell crisis?
Sudden enlargement of the spleen causing a decrease in Hb concentration, circulatory chock, and hypovolaemic shock. Occurs in babies and young children.
What is an acute chest syndrome sickle cell crisis?
Vaso-occlusive crisis affecting the lungs with a new pulmonary infiltrate on CXR with fever/cough/sputum production/tachypnoea/dyspnoea.
What is a haemolytic sickle cell crisis?
An uncommon sickle cell crisis where there is an increased rate of haemolysis with a fall in Hb level.
A patient with known sickle cell disease presents with pain, neurological signs, tachypnoea, and painful swollen joints. What is probably going on?
Vaso-occlusive sickle cell crisis
A patient with known sickle cell disease presents with shortness of breath, and CXR shows pulmonary oedema. What is the top differential?
Aplastic crisis
A child with known sickle cell disease presents with abdominal pain, shock, and a LUQ mass on examination? What is the top differential?
Sequestration crisis
What are the general measures used to manage sickle cell crises?
- Analgesia
- Hydration
- Oxygen
- Folic acid
- Abx
- Exchange transfusion as appropriate
What is DIC?
Disseminated intravascular coagulation is a syndrome characterised by systemic activation of blood coagulation leading to thrombosis of small/medium vessles, and eventual clotting factor exhaustion and haemorrhage.
What causes DIC?
It occurs in response to a triggering event, not due to any predisposing lifestyle factors.
What is the most common cause of DIC?
Sepsis
Other than sepsis, what can trigger DIC?
Malignancy esp. leukaemias Major trauma Transfusion/transplant reaction Severe liver disease Pancreatitis Recreational drugs Complications post-surgery
In acute DIC, where do patients tend to bleed from?
- E, N, & T
- GI tract
- Respiratory tract
- Site of venepuncture of IV line insertion
What dermatological signs might a pt with DIC exhibit?
- Petechiae
- Purpura
- Haemorrhagic bullae
- Peripheral cyanosis
- Signs of thrombosis
- Localised infarction/gangrene/necrosis
What single tests can aid diagnosis of DIC?
Tricked ya - none of them can!
Seriel tests of multiple factors need to be done to moniotr change over time. This includes:
- Fibrin degradation products
- Platelets
- Prothrombin time
- APTT
- Fibrinogen
What fibrin degradation products can be measured to test for DIC?
Elevated D-dimer - it is not specific to DIC, but a normal D-dimer is highly sensitive in excluding DIC.
How will prothrombin time be altered in DIC?
It will be elevated as clotting factors have been used up
How will platelets be altered in DIC?
They will be low following a steady decline. This may be a steady decline within normal range.
How will APTT time be altered in DIC?
It will be elevated as clotting factors have been used up
How will fibrinogen be altered in DIC?
Low or normal as it has been used up to help form fibrin to make clots
How should DIC be managed?
Treat the underlying cause, and the DIC should resolve.
Blood products should be reserved for those with active bleeding or at high risk of an actuve bleed.
