Anaemia - introduction + microcytic Flashcards
What is the definition of anaemia?
haemoglobin (Hb) level <120 g/L (<12 g/dL) in females
<130 g/L (<13 g/dL) in males
<110 g/L (11 g/dL) in pregnant women
What is the most common cause of anaemia?
iron deficiency
what are the sx of anaemia?
fatigue SOB faintness palpitations headache tinnitus anorexia
How can anaemia present in coronary artery disease?
angina
What are possible signs of anaemia?
Pallor
Hyperdynamic circulation e.g. tachycardia, flow murmurs, cardiac enlargement
What are the causes of microcytic anaemia?
- Iron deficiency anaemia
- Thalassaemia
- Sideroblastic anaemia
What are the causes of normocytic anaemia?
- acute blood loss
- anaemia of chronic disease
- BM failure
- RF
- Hypothyroidism
- Haemolytic anaemia
- Pregnancy
- aplastic
What are the causes of microcytic anaemia?
- B12 or folate deficiency
- Alcohol XS
- Reticulocytosis
- Cytotoxics
- Myelodysplastic syndromes
- Marrow infiltration
- Hypothyroidism
What MCV level is microcytic anaemia?
<80fl
What MCV level is macrocytic anaemia?
> 100fL
what are the causes of iron deficiency anaemia?
- inadequate iron intake - malabsorption e.g. coeliac
- increased iron loss - menorrhagia, GI bleeding
- XS iron requirements
What are the key diagnostic features of iron deficiency anaemia?
- fatigue
- pica
- nail changes - thinning, flattening, koilonychia (rare)
- hair loss
What investigations would you do to confirm iron deficiency anaemia?
- FBC - Hb, MCV, MCH, MCHC, platelets
- peripheral blood smear
- serum ferritin, iron
- Transferrin
- low reticulocyte
What investigations may u consider to identify the cause of iron deficiency anaemia?
- Coeliac serology - IgA tissue transglutaminase + total IgA
- H. Pylori testing - IgG abs or faecal antigen, confirm w urease breath test or endoscopy w biopsy
What is the treatment of iron deficiency anaemia?
- oral iron - ferrous sulphate (2-3mg/kg/day in 2-4 doses)
2. ascorbic acid if response to oral iron is poor
How long should rx of IDA be continued after Hb correction?
3-6 months
When are transfusions recommended in IDA?
If haemodynamically unstable - symptomatic at rest w SOB, CP, presyncope
What are there causes of anaemia of chronic disease?
autoimmune disorders
malignancy
acute/chronic infection
critical illness, trauma
What tests would u do in ACD?
- FBC
- Blood smear
- B12, folate
- TSH
- Tests for haemolytic
what is the treatment of ACD?
- Rx underlying disease
2. Transfusion
what is sideroblastic anaemia?
ineffective erythropoiesis
leading to ↑iron absorption, iron loading in marrow ± hae- mosiderosis
what is haemosiderosis
endocrine liver and heart damage due to iron deposition
What are the causes of sideroblastic anaemia?
- congenital
2. acquired - myelodysplasia, alcohol XS, anti-TB meds, lead XS
What tests would you do for sideroblastic anaemia and what would you find?
Blood film - hypochromic microcytic anaemia
BM - sideroblastis + ↑ iron stores
What is the rx of sideroblastic anaemia?
supportive
rx cause
pyridoxine may help
What serum ferritin levels are diagnostic of IDA?
<12 ng/ml
What would you see on peripheral blood smear in IDA?
Microcytic hypochromic pencil red cells
What is the pathology underlying beta-thalassaemia?
mutation(s) of the beta-globin gene leading to decreased or absent synthesis of beta-globin, resulting in ineffective erythropoiesis
How is beta thalassaemia further subdivided?
- Minor - heterozygous
- Intermedia
- Major - homozygous
How does beta thalassaemia minor present?
asymptomatic, carrier state
mild/absent anaemia
How does beta thalassaemia intermedia present?
mod anaemia not requiring transfusions
splenomegaly
How does beta thalassaemia major present?
severe anaemia in 1st year of life failure to thrive hepatosplenomegaly recurrent infections skull bossing osteopenia
What may appear on skull XR in beta thalassaemia major?
Hair on end sign
what is the inheritance pattern of beta thalassaemia?
autosomal recessive
What is seen on blood film in beta thalassaemia?
microcytic anaemia
tear drops
target cells
microspherocytes
What is the treatment of beta thalassaemia trait?
genetic counselling
avoid iron supplementation
What is the treatment of beta thalassaemia major?
regular red cell transfusions (keep Hb >100g/dl)
Iron chelation - desferrioxamine
Splenectomy if massive
What is the treatment of beta thalassaemia intermedia?
transfusions if profound anaemia
What is the risk of repeated transfusions? what can be done to reduce the risk?
damage of endocrine glands, liver, pancreas and heart
death in 2nd decade from HF
Reduce: iron chelation, ascorbic acid
What chromosomes are affected in alpha and beta thalassaemia?
beta - 11
alpha - 16
How can alpha thalassaemia present?
asymptomatic carrier state to incompatible with life
How does AT present if all 4 alpha genes are deleted?
death in utero - Bart’s hydrops
How does AT present if 3 alpha genes are deleted?
moderate anaemia
features of haemolytic - hepatosplenomegaly, leg ulcers, jaundice
How does AT present if 2 genes are deleted?
asymptomatic carrier satte w hypochromic microcytic blood film but normal Hb
