iron deficiency anaemia W8 Flashcards
anaemia definition?
serum haemoglobin levels are 2 standard deviations below the normal
iron deficiency definition?
total body iron is low as a result of absorption not matching demand
IDA epidemiology?
iron deficiency anaemia in 2-5% adult males and non-menstruating females
10% of these with have underlying malignancy
if iron deficient but not anaemic, around 1% will have an underlying malignancy
causes of IDA?
poor intake of dietary iron
reduced absorption (malabsorption) eg coeliac, post surgery
increased iron (blood) loss eg menstruation, cancer
increased demand eg pregnancy, adolescence
IDA symptoms?
often none
common symptoms - tiredness, dyspnoea, headache
common signs - pallor, atrophic glossitis
rarer signs - koilonychia, leukonychia, tachycardia, angular cheilosis
iron absorption?
2 forms:
Fe2+ = haem iron (found in red meat, sea food. readily absorbed by the body.)
Fe3+ = non-haem iron (less absorbable, needs to be converted to Fe2+.)
iron absorption - enhancers?
vit C
fructose
sorbitol
alcohol
iron absorption - inhibitors?
tannins
oxalates
polyphenols
phytates
egg, pulse proteins
calcium
copper
manganese
what part of the body is iron used in? what is it essential for?
muscle, liver, bone marrow, spleen
essential for enzymes
enterocyte iron absorption
Fe3+ harder to absorb than Fe2+
body stores iron within cells as ferritin, this is what is measured for total body iron stores.
main condition IDA is confused with?
anaemia of chronic disease
mechanism of anaemia of chronic disease (AoCD)?
caused by ongoing inflammation.
-increases hepatic synthesis of hepcidin (inhibits release of iron from RES)
-inhibits erythropoietin release
-inhibits erythroid proliferation
-augments hemophagocytosis
what is a marker of total body iron stores?
ferritin (not serum iron)
how to tell the difference between iron deficiency anaemia and AoCD?
low ferritin = IDA
transferrin high = IDA
transferrin normal/low = AoCD
explanation of transferrin levels?
body’s iron is low, therefore more transferrin is made to move more iron
body has full iron stores (eg in AoCD), transferrin levels normal/low as don’t need to move iron around the body
iron deficiency anaemia defined as?
low haemoglobin in the presence of either
-low ferritin (best diagnostic marker)
-low serum iron in the presence of transferrin >3.0
what can iron deficiency anaemia be caused by
loss of iron (menstrual, GI, renal)
malabsorption (previous gastric surgery, coeliac disease)
poor dietary iron intake (poor diet, lifestyle choices, cultural beliefs)
what test should everyone get in IDA?
coeliac disease (anti tTG antibodies)
commonest cause of IDA?
menstrual blood loss
transnasal endoscopy positives/negatives?
positive -
better tolerated
usually only under local anaesthetic
biopsy standard equivalency
endoscopy only test able to adequately visualise the stomach
negative -
unable to perform most therapeutic procedures
standard colonoscopy positives?
remains gold standard
able to take biopsies and perform polypectomy
standard colonoscopy negatives?
invasive
can be uncomfortable
need to take prep
can miss lesions
possibilities of complications - bleeding/perforation
CT colonoscopy positives?
mostly non-invasive
min prep for frail patients
fast
less risks
effective as colonoscopy for polyps >5mm
CT colonoscopy negatives?
still need to take prep
radiation dose
if shows lesion will still need colonoscopy
can result in incidentalomas
