Haematology Flashcards
What are the causes of microcytic anaemia
TAILS
Thalassaemia
Anaemia of chronic disease
Iron deficiency anaemia
Lead poisoning
Sideroblastic anaemia
What are the causes of normocytic anaemia
3 As, 2 Hs
Acute blood loss
Anaemia of chronic disease
Aplastic anaemia
Haemolytic anaemia
Hypothyroidism
What are the causes of macrocytic anaemia
Megaloblastic: due to impaired DNA synthesis, B12 deficiency, folate deficiency
Normoblastic: alcohol, reticulocytes, hypothyroidism, liver disease, azathioprine
What are the symptoms of anaemia
Tiredness
Shortness of breath
Headache
Dizziness
Palpitations
Worsening of other conditions
Specific to iron deficiency anaemia: pica, hair loss
What are the signs of anaemia
Pale skin
Pale conjunctiva
Tachycardia
High respiratory rate
Koilonychia - iron deficiency
Angular cheilitis - iron deficiency
Atrophic glossitis - iron deficiency
Brittle hair and nails - iron deficiency
Jaundice - haemolytic
Bone deformities - thalassaemia
What investigations are needed for anaemia
Initial: Hb, MCV, B12, folate, ferritin, blood film
Further: OGD and colonoscopy, bone marrow biopsy
What are the mechanisms of iron deficiency anaemia
Insufficient dietary intake
Increased requirement (pregnancy)
Loss (menorrhagia, GI cancers)
Inadequate absorption (coeliac, IBD, PPIs)
What is the management for iron deficiency anaemia
Blood transfusions
Iron infusion
Oral iron (not suitable if due to malabsorption)
What is pernicious anaemia
Can cause B12 deficiency anaemia
Autoimmune (antibodies against parietal cells, intrinsic factor - B12 can not be absorbed)
What are the symptoms of pernicious anaemia
Peripheral neuropathy
Paraesthesia
Loss of vibration sense
Loss of proprioception
Vision changes
Mood changes
What investigations are needed for pernicious anaemia
Intrinsic factor antibodies
Gastric parietal cell antibodies
What is the management for pernicious anaemia
Oral replacement (cyanocobalamin)
IM hydroxycobalamin (3 times a week for 2 weeks, then every 3 months)
If also have folate deficiency, treat B12 deficiency first
What are the inherited causes of haemolytic anaemia
Hereditary spherocytosis
Hereditary elliptocytosis
Thalassaemia
Sickle cell anaemia
G6PD deficiency
What are the acquired causes of haemolytic anaemia
Autoimmune haemolytic anaemia
Transfusion reaction
Haemolytic disease of the newborn
Paroxysmal nocturnal haemoglobinuria
Microangiopathic haemolytic anaemia
Prosthetic valve related haemolysis
What are the main features of haemolytic anaemia
Anaemia
Splenomegaly
Jaundice
What investigations are needed in haemolytic anaemia
FBC (normocytic anaemia)
Blood film (schistocytes)
Direct Coombs test (positive in autoimmune haemolytic anaemia)
What is sickle cell anaemia
Crescent shaped RBCs
Fragile, easily destroyed
Get haemolytic anaemia
Patients have HbS variant
Autosomal recessive
Protective against malaria
How can sickle cell anaemia be diagnosed
High risk women offered test during pregnancy
Heel prick test
What are the complications of sickle cell anaemia
Anaemia
Increased infection risk
Stroke
Avascular necrosis of large joints
Pulmonary hypertension
Priapism
CKD
Sickle cell crisis
Acute coronary syndrome
What is the management for sickle cell anaemia
Avoid dehydration
Ensure vaccinations up to date
Antibiotic prophylaxis (penicillin V)
Hydroxycarbamide (stimulates production of HbF)
Blood transfusion
Bone marrow transplant (curative)
Give an overview of sickle cell crisis
Triggers: stress, infection, dehydration, cold, significant life event
Supportive management: low threshold for admission, treat any infection, keep warm, keep well hydrated, simple analgesia, penile aspiration (for priapism)
What is thrombocytopenia
Low platelet count
What are the causes of thrombocytopenia
Problems with production: sepsis, B12/folate deficiency, liver failure, leukaemia, myelodysplastic syndrome
Problems with destruction: medications (sodium valproate, methotrexate, antihistamines, PPIs), alcohol, immune thrombocytopenia purpura, thrombotic thrombocytopenic purpura, heparin-induced thrombocytopenia, haemolytic uraemic syndrome
How might thrombocytopenia present
Mild: asymptomatic
Moderate: spontaneous bruising, prolonged bleeding time, nosebleeds, bleeding gums, menorrhagia, bloody urine/stool
Severe: high risk of spontaneous bleeding
What are the differentials for prolonged bleeding
Thrombocytopenia
Haemophilia A/B
Von Willebrand disease
Disseminated intravascular coagulation
What are the risk factors for DVT
Immobility
Recent surgery
Long haul flights
Pregnancy
HRT (with oestrogen)
Malignancy
Polycythaemia
SLE
Thrombophilia
What are the contraindications for VTE prophylaxis
Active bleeding
Already on anticoagulation
Which LMWH is most commonly used for VTE prophylaxis
Enoxaparin
How might DVTs present
Unilateral
Calf/leg swelling
Dilated superficial veins
Calf tenderness
Oedema
Leg colour changes
How are DVTs diagnosed
Assess using Wells score
D-dimer (sensitive, not specific)
Doppler ultrasound (if negative but symptoms suggestive, repeat after a few days)
What is the management for DVTs
Initial: treatment dose LMWH (enoxaparin, dalteparin)
Long term: warfarin, NOAC, LMWH. Continue for: 3 months if obvious reversible cause, 3-6 months if cause unclear or recurrent, 6 months in active cancer
What is the NICE guideline regarding first unprovoked DVTs
Investigate for possible cancer: CXR, bloods, urine dip, CT abdo-pelvis, mammogram
If family history of VTE, assess for hereditary thrombophilias
