Anaemia Flashcards
what is anaemia?
Low haemoglobin which is:
Men <13.5g/dl
Women <11.5g/dl
what are symptoms of anaemia?
fatigue dyspnoea faint palpitations headache tinnitus
Normally symptoms are due to cause more than anaemia
what is the diagnostic approach to anaemia?
FBC to confirm anaemia
MCV to categorise anaemia
Microcytic: iron panel
normocytic: reticulocyte count to assess bone marrow
Macrocytic:
Peripheral blood smear to decide if it’s megaloblastic or non-megaloblastic.
What are the classifications of anaemia based on MCV?
MCV <80fL: microcytic
MCV 80-100fL: normocytic
MCV >96: macrocytic
what are causes of microcytic anaemia?
IRON LAST Iron deficiency Lead poisoning Anaemia of chronic disease Sideroblastic anaemia Thalassaemia
what is the most common cause of microcytic anaemia?
iron deficiency
what are the investigation results seen in iron deficient anaemia?
Low serum iron Low ferritin High transferrin High TIBC Low TIBC SATURATION Blood films can show poikilocytosis, target and pencil cells
what are clinical features of iron deficient anaemia?
fatigue SOB Palpitations pallor hair loss atrophic glossitis angular stomatis
what tests might you consider doing in someone with iron deficient anaemia?
occult blood tests, haemoglobin electrophoresis, anti-TTG
endoscopy/colonoscopy
Men of any age with a Hb under 110g/L should be referred under 2WW
Patients >60 should be referred for colonoscopy
what is the management for iron deficient anaemia?
Ferrous sulfate oral TDG 200mg.
reticulocyte count will improve in 7 days and treatment should carry on for 5-6 months
what is sideroblastic anaemia?
Iron granules form a ring around the nucleus in developing erythroblasts due to a defect in haem synthesis.
what type of anaemia does sideroblastic anaemia cause?
Hypochromic microcytic picture
what are investigation findings in sideroblastic anaemia?
low TIBC
Raised serum iron
hypochromic RBC’s
ringed sideroblasts
what is the management of sideroblastic anaemia?
regular transfusions and iron chelation
what is the effect of haemolysis on reticulocyte count?
Increased as more RBC’s are produced by the bone marrow to try and compensate
what are causes of normocytic anaemia?
Anaemia of chronic disease CKD/RA Pregnancy (due to increased plasma volume) acute blood loss Aplastic anaemia Haemolytic anaemias
what is aplastic anaemia?
Bone marrow failure causes a normocytic anaemia, leukopenia and thrombocytopenia
what are causes of aplastic anaemia?
phenytoin, sulphonamides, chloramphenicol, ALL, AML, parvovirus, hepatitis
Congenital is X linked recessive
what are investigation findings in aplastic anaemia?
low reticulocyte count (as bone marrow can’t produce new RBC’s)
neutropenia
what is diagnostic Ix for aplastic anaemia?
Bone marrow biopsy
what are type of haemolytic anaemia?
Intrinsic defects:
- Haemoglobinopathies (sickle cell, HbC)
- enzyme deficiencies (pyruvate kinase deficiency, G6PD deficiency)
- Membrane defects (Paroxysmal nocturnal haemoglobinuria, hereditary spherocytosis)
Extrinsic defects: autoimmune haemolytic anaemia, microangiopathic haemolytic anaemia, infections or mechanical destruction
what are the two categories of macrocytic anaemia?
megaloblastic vs non megaloblastic
Megaloblastic: Have large and immature nuclei due to delayed nuclear maturation with defective DNA synthesis
Non-megaloblastic:
Normal DNA synthesis and no hypersegmented neutrophils
what are causes of megaloblastic macrocytic anaemia?
Vitamin B12 deficiency
Folate deficiency
Myelodysplasia
what is the neurological consequence of vitamin B12 deficiency?
Subacute combined degeneration of the spinal cord
- affects the pyramidal and dorsal columns
- symmetrical polyneuropathy
what are causes of vitamin B12 deficiency?
Inadequate intake: poor diet, vit B12 comes from animal sources mainly milk, eggs etc
Malapsorption: Perncious anaemia, gastrectomy, congenital intrinsic factor deficiency
intestinal causes:
bacterial colonisation, ileal resection, crohns disease
what is pernicious anaemia?
autoimmune gastritis and reduced secretion of intrinsic factor and acid.
Often have antibodies to intrinsic factor and parietal cells
what investigations can you consider for someone with b12 deficiency?
intrinsic factor antibody
parietal cell antibodies
serum gastrin levels
upper GI endoscopy
what is the management of vit b12 deficiency?
1mg IM hydroxocobalamin
*if folate and b12 deficient treat the B12 first to prevent neuropathy
what is the most common cause of Vit B12 deficiency?
Pernicious anaemia.
how much folate acid does the body store?
4 months worth
why does pernicious anaemia lead to vit B12 defiency?
You have intrinsic factor antibodies which bind to intrinsic factor preventing vitamin B12 binding
You have gastric parietal cell antibodies which mean reduced acid production and atrophic gastritis. This leads to less intrinsic factor being produced and therefore less VitB12 absorption.
what is vitamin B12 important for?
Production of blood cells
Myelination of nerves
what antibody test is most specific for pernicious anaemia?
Anti intrinsic factor antibodies is highly specific
Anti gastric parietal cell antibodies are sensitive but have low specificity.
what are causes of folate deficiency?
Nutritional: old age, poverty and famine
Malabsorption: Gluten induced enteropathy, dermatitis herpetiformis
Increased use: pregnancy, lactation, haemolytic anaemia, carcinoma, lymphoma, myeloma, corhns, RA, malaria.
excess urinary loss: congestive heart failure and chronic dialysis
drugs: anticonvulsants and sulfasalazine
mixed: liver disease and alcoholism
what are causes of non megaloblastic macrocytic anaemia?
Pregnancy alcohol excess liver isease hypothyroid myeloma myeloma reticulocytosis
what are the associations of plummer vinson syndrome?
Iron deficient anaemia
Dysphagia (post cricoid)
Oesophageal webs
- increased risk of glossitis and oesophageal SCC.
what is one of the biggest causes of macroytosis?
Alcohol aplastic anaemia cytotoxic drugs myeloma liver disease myxoedema pregnancy newborn
