T7-T12: Haematological Emergencies Flashcards
What is the pathogenesis of Thrombotic Thrombocytopenic Purpura?
There is a severe reduced activity of the ADAMTS13 enzyme. This enzyme usually breaks down large vWF - as a result reduced activity leads to large vWF. This leads to activity leads to intravascular thrombosis and shearing of RBC as they pass through the fibrin network. This is usually due to an autoantibody against the enzyme. It can be genetic or inherited such as in pregnancy or other illnesses. The bone marrow throws out large immature RBC to compensate. There is a low platelet count also as the bone marrow replaced RBC. It is a medical emergency as fatal if untreated.
What are the symptoms and tests involved in TTP?
TTP - Thrombotic Thrombocytopenic Pura
Symptoms:
- Confusions, seizures, strokes
- Fever
- Renal failure
- Organ ischaemia due to thrombosis such as MI in young patients
Tests:
- FBC
- Blood film looking for polychromasia and fragmented RBC
- Haemolysis screen: FBC with reticulocyte count, billirubin, LDH, DCT, blood film, Haptoglobin
- Group and Save
- Troponin to see heart involvement
- ADAMTS13 levels
- Hep B/C and HIV serology as TTP can mimic a similar condition
- Pregnancy test
What is the treatment for TTP?
TTP - Thrombotic Thrombocytopenic Pura
- Urgent plasma exchange - replace ADAMTS13 and remove autoantibody
- Suppress antibody production: Steroids, Riuximab
- Prevent Thrombosis in low platelet - Aspirin, LMWH
- Calacizumab - vWF inhibitor
How do we treat Acute Leukaemia?
We need to do a bone marrow biopsy to diagnose whether it is myeloid or lymphoid leukaemia.
Treatment:
- Antibiotics for infection
- Blood products as often patients present with pancytopenia
- Intensive chemotherapy
- Also new less invasive therapies
What is the treatment for Spinal Cord Compression in Myeloma?
- Dexamethosone - reduce tumour size
- Radiotherapy if mainly soft tissue (needs to be done within 24 hours)
- Occasionally may need surgery
- Hydration and bisphopshate for high calcium
- Pain relief
(- Myeloma Screen - serum protein electrophoresis and serum free light chain)
What are causes of Superior Vena Cava Obstruction (SVCO)?
- Non-malignant causes such as thrombosis in the VC
- Malignant - such as Lung cancer or Lymphoma or Metastases
This leads to symptoms of:
- face and upper limb swelling
- Breathlessness
- Headaches
- Distended chest wall veins
What is Tumour Lysis Syndrome?
The breakdown of tumour cells once chemotherapy or even steroids have been started. This leads to the release of intracellular potassium and phosphate.
There is a raised uric acid - uric acid is insoluble and can form crystals particularly in the kidney leading to anuria.
This can lead to:
- Renal failure
- Cardiac arrhythmia due to hyperkalaemia
- Hypocalcaemia as it precipitates with excess phosphate
- Confusion and seizures and so may require ICU
- Can be fatal
What is the action of Rusburicase?
Converts Uric acid to a more soluble form.
What type of bacteria typically cause rapid and overwhelming neutropenic sepsis?
Gram Negative Bacteria
What test do we use to test lactate levels in Neutropenic Sepsis?
- Venous blood gas (ABG and catheter inversion should be avoided as it can lead to bleeding)
What severe reactions can we see to CAR-T therapy, some types of antibody therapy (such as Blinatumuab) and some types of stem cell transplant in mismatch?
- Cytokine release syndrome - results in the release of inflammatory cytokines. Presetantion is usually high fever, hypotension and hypoxia. Treatment broad-spectrum antibiotics, IV fluid/oxygen and IL6 block.
- Immune Cell Related Toxicity
What scoring systems are used to determine therapy in Immune Cell related Toxicity?
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