macrocytic anaemia Flashcards
how is macrocytic anaemia seen on blood results?
low Hb high MCV
what is the initial investigation for macrocytic anaemia
blood smear
if hyper-segmented nucleus is seen on blood smear, what is the cause of the macrocytic anaemia?
megaloblastic anaemia - folate of B12 deficiency
if there’s no hyper-segmented nucleus seen on blood smear what is the cause of macrocytic anaemia?
non-megaloblastic anaemia
liver disease, alcohol, hypothyroidism, myelodysplasia, myeloma
megaloblastic anaemia - b12 deficiency causes
pernicious anaemia, atrophic gastritis PPIs
bacterial overgrowth, pancreatic dysfunction, malabsorption
diet - vegans
what is pernicious anaemia?
autoimmune destruction of gastric parietal cells (most common)
intrinsic factor deficiency + b12 deficiency
how does a patient with b12 deficiency present?
fatigue
jaundice
glossitis
peripheral neuropathy
spinal cord degeneration
what investigations are used in b12 deficiency?
bloods - pancytopenia, macro-valocytes and hyper-segmented nucleus - methylmalonic acid
autoantibodies - anti-IF, anti-parietal cells
what is the management of b12 deficiency?
vit b12 injections for life
what are the causes of folate deficiency?
inadequate intake (alcoholics)
malabsorption
pregnancy, haemolysis
anticonvulsants
how does a patient with folate deficiency present?
signs of anaemia (fatigue, pallor), glossitis
what investigations are used in folate deficiency?
high MCV/MCH, hyper-segmented nucleus
what is the management of folate deficiency?
folic acid supplements until recovered
why can reticulocytosis cause a false high MCV?
increase in reticulocytes occurs in haemolysis and haemorrhage
what will haemolysis cause?
increased products of red cell destruction
bleeding = nothing to break down
why does jaundice and dark urine occur in non-megaloblastic anaemia?
increase in products from red cell breakdown
increased unconjugated bilirubin - jaundice
increased urinary urobilirubin - dark urine
