Haematology Flashcards
ITP definition?
Immune-mediated reduction in the platelet count. Antibodies are directed against the glycoprotein IIb/IIIa or Ib-V-IX complex.
ITP in children vs. adults?
- Children = acute post infection/vaccination
- Adults = chronic
ITP presentation?
- Incidentally following routine bloods
- Symptomatic = petechiae, purpura, bleeding, catastrophic bleeding uncommon
ITP Rx?
- Oral prednisolone
- IVIG (raises plts quickly, use if active bleeding or urgent invasive procedure)
- Splenectomy rarely
Evan’s syndrome?
ITP + AIHA
Blood product transfusion complications x5?
- Immune
- Infective
- TRALI
- TACO
- Other = hyperkalaemia, iron overload, clotting
Immunological transfusion reactions?
- Acute haemolytic
- Non-haemolytic febrile
- Allergic/anaphylaxis
Acute haemolytic reaction mushkies?
- ABO incompatible blood e.g. human error
- Fever, abdominal pain, hypotension
- Rx = stop transfusion, confirm Dx, send blood for Coombs, repeat typing and cross matching, supportive care with fluid resuscitation
Non-haemolytic febrile reaction mushkie?
- White blood cell HLA antibodies, often the result of sensitization by previous pregnancies or transfusions
- Fever, chills, red cells (1%), platelets (10-30%)
- Rx = slow or stop transfusion, paracetamol, monitor
Anaphylaxis reaction mushkies?
- Patients with IgA deficiency who have anti-IgA antibodies
- Stop transfusion, IM Adrenaline, ABC
Minor allergic reaction mushkies?
- Foreign plasma proteins
- Pruritis, urticaria
- Temporarily stop the transfusion, antihistamine, monitor
TACO mushkies?
- Excessive rate of transfusion, pre-existing heart failure
- Pulmonary oedema, hypertension
- Rx = Slow or stop the transfusion, consider loop diuretic and oxygen
TRALI mushkies?
- Non-cardiogenic pulmonary oedema thought to be secondary to increased vascular permeability caused by host neutrophils that become activated by substances in donated blood, within 6 hours of transfusion
- Hypoxia, pulmonary infiltrates on chest x-ray, fever, hypotension
- Rx = stop the transfusion, oxygen and supportive care
Differentiating between TACO and TRALI?
TACO = hypertension
Critical mediator of DIC?
TF (Tissue factor) = TF binds with coagulation factors that then triggers the extrinsic pathway (via Factor VII) which subsequently triggers the intrinsic pathway (XII to XI to IX) of coagulation
DIC causes?
- Sepsis
- Trauma
- Obstetric complications (amniotic fluid embolism, haemolysis, HELLP)
- Malignancy
DIC bloods Dx?
- Low platelets and fibrinogen
- Raised PT, APTT and fibrinogen degradation products
- Schistocytes due to MAHA
Warfarin clotting effect?
Prolonged PT
Aspirin clotting effect?
Prolonged bleeding time
Heparin clotting effect?
APTT prolonged (although PT ay be prolonged)
Warfarin antidote?
Vitamin K
Dabigatran antidote?
Idarucizumab
Heparin antidote?
Protamine sulphate
Dabigatran mushkies?
- MOA = direct thrombin inhibitor
- Excretion = majority renal
Rivaroxaban mushkies?
- MOA = direct factor Xa inhibitor
- Excretion = majority liver
- Antidote = andexanet alfa
Apixaban mushkies?
- MOA = direct factor Xa inhibitor
- Excretion = majority faecal
- Antidote = andexanet alfa
Edoxaban mushkies?
- MOA = direct factor Xa inhibitor
- Excretion = majority faecal
- Antidote = none
Sickle cell crises types x5?
- Thrombotic (painful)
- Sequestration
- Acute chest syndrome
- Aplastic
- Haemolytic
Sickle cell thrombotic crisis mushkies?
- AKA Painful/vaso-occlusive crises
- Precipitated by infection, dehydration, deoxygenation
- Clinical diagnosis
- Infarcts in various organs e.g. Hip AVN, hand-foot syndrome in children, lungs, spleen, brain
Sequestration crises mushkies?
- Sickling within organs such as the spleen or lungs causes pooling of blood with worsening of the anaemia
- Associated with an increased reticulocyte count
Acute chest syndrome mushkies?
- Vaso-occlusion within the pulmonary microvasculature → infarction in the lung parenchyma
- Fx = dyspnoea, chest pain, CXR pulmonary infiltrates, low pO2
- Rx = analgesia, oxygen, Abx, transfusion (improves oxygenation)
- Most common cause of death after childhood
Aplastic crisis mushkies?
- Parvovirus infection causes sudden fall in Hb
- Bone marrow suppression causes a reduced reticulocyte count
Sickle cell haemolytic crisis mushkies?
- Rare, fall in Hb due to increased rate of haemolysis
Microcytic anaemia causes?
TAILS
1. Thalassaemina
2. ACD
3. IDA
4. Lead poisoning
5. Sideroblastic anaemia
New onset microcytic anaemia in elderly pt Rx?
2ww
Microcytosis disproportionate to anaemia?
Beta thalassaemia minor
Most common inherited bleeding disorder?
Von Willebrand’s Disease
Von Willebrand’s Disease inheritance?
Usually AD
vWF role?
- Large glycoprotein which forms massive multimers
- Promotes platelet adhesion to damaged endothelium
- Carrier molecule for factor VIII
VWD Types?
- Type I = partial reduction of vWF (80%)
- Type II = abnormal form of vWF
- Type III = total lack of vWF (AR)
vWD clotting?
- Prolonged bleeding time
- APTT may be prolonged, Factor VIII levels may be moderately reduced
- Defective platelet aggregation with ristocetin
vWD Rx?
- Tranexamic acid for mild bleeding
- DDAVP = raises levels of vWF by inducing release of vWF from Weibel-Palade bodies in endothelial cells
- Factor VIII concentrate
What is PCC?
Concentrate of the four vitamin K dependents factors
Causes of massive splenomegaly?
- Haem = CML, myelofibrosis
- Infection = VL, Malaria
- Metabolic = Gaucher’s
CML pathophysiology?
Philadelphia chromosome in 95%. It is due to a translocation between the long arm of chromosome 9 and 22 - t(9:22)(q34; q11). This results in part of the ABL proto-oncogene from chromosome 9 being fused with the BCR gene from chromosome 22. The resulting BCR-ABL gene codes for a fusion protein that has tyrosine kinase activity in excess of normal
CML presentation?
- Splenomegaly
- Increase in granulocytes at different stages of maturation +/- thrombocytosis
- Decreased leukocyte alkaline phosphatase
- May undergo blast transformation (AML in 80%, ALL in 20%)
CML Rx?
- Imatinib 1st line = inhibitor of tyrosine kinase associated with BCR-ABL, very high response rate in chronic phase CML
- Hydroxyurea
- IFN-a
- Allogenic bone marrow transplant
Multiple myeloma definition?
A haematological malignancy characterised by plasma cell proliferation. It arises due to genetic mutations which occur as B-lymphocytes differentiate into mature plasma cells. MM is the second most common haematological malignancy.
Multiple myeloma features?
CRABBI
1. Calcium = hypercalcaemia due to increased osteoclast activity in bone
2. Renal = light chain deposition in renal tubules, causes renal damage
3. Anaemia
4. Bleeding
5. Bone pain and fractures
6. Infection
Multiple myeloma Ix?
- Bloods = anaemia, thrombocytopenia, raised urea and creatinine, raised calcium
- Peripheral blood film = Rouleaux
- Serum/urine protein electrophoresis = raised concentrations of monoclonal IgA/IgG proteins will be present in the serum. In the urine, they are known as Bence Jones proteins
- Bone marrow aspiration and trephine biopsy = confirms the diagnosis if the number of plasma cells is significantly raised
- Whole body MRI = Skeletal survey for bone lesions
Multiple myeloma X-ray finding?
Raindrop skull