Iron Deficiency Anaemia Flashcards
What is the physiology of iron use in the body?
Small fraction of iron we eat is absorbed in the duodenum
- Enhanced by consuming with vitamin C; animal sources > plant sources
Released into bloodstream and binds to transferrin (3-4mg) - which transports to the liver
In the liver, the iron is stored as ferritin; total iron in body c. 400mg
Ferritin is released as required to the bone marrow for the synthesis of the haemoglobin in more red cells
Once an RBC is no longer functioning (120 days in normal body states) they are resbsorbed in the spleen
Iron from this process is recycled (20mg/day)
Iron is also used for:
- Cell maintenance
- Skin, hair and nail maintenance
- Myoglobin synthesis
- Redox reactions in liver
What are the causes/risk factors for iron deficiency anaemia?
Disease states:
- Coeliac disease, IBD, peptic ulcer disease, gastric bypass surgery
- Blood loss from anywhere - GI tract/chronic nosebleeds/renal or bladder/frequent blood donations; DIC
- Recent major surgery/physical trauma
Women:
- Heavy menstruation
- Pregnancy, breastfeeding, recent birth
Dietary:
- Insufficient vegetarian or vegan diets
- Malnutrition
How does iron deficiency anaemia present?
Same general features of all anaemias:
- Fatigue
- Dyspnoea
- Weakness
- Exercise intolerance
- Headache
- Faintness/dizziness
- Palpitations
- Picophagia e.g. craving eating ice or clay etc.
- Pallor (esp. conjunctivae, nail beds), tachycardia, cold extremities (cardiomegaly, heart failure)
Other signs:
- Brittle nails
- Spoon shaped nails -
- Cracks + inflammation at sides of mouth (angular cheilitis)
- Mouth ulcers
- Large red tongue (glossitis)
- Thin hair
- Easy bruising
- Restless leg syndrome
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What are the blood results for iron deficiency anaemia?
Small MCV + low HB = Microcytic anaemia
Low ferritin = key test in primary care
Low serum iron; Increased total iron binding capacity (TIBC) or transferrin
High ZPP - If there is not enough iron available, then protoporphyrin combines with zinc instead of iron to form zinc protoporphyrin
Blood film:
Small oval shaped cells with pale centres (microcytic, hypochromic)
Low-normal reticulocytes
Target cells; pencil/cigar cells
How do you manage iron deficiency anaemia?
Supplementary iron
Ferrous sulphate 200mg PO BD/TDS (65mg elemental iron)
Iron stores replenished by 3months - maintain treatment for 3-6m total
SE: constipation most common; GI discomfort, N+V, dark stools
Can reduce adverse effects by taking with food; dose/frequency can be reduced or different drug given (ferrous gluconate) to improve tolerance
Also address diet where appropriate
What monitoring is recommended for someone being treated for iron deficiency anaemia?
Recheck FBC after 2-4wks treatment
Haemoglobin concentration should rise by about 2 g/100 mL over 3–4 weeks
Treatment failure is most likely due to non-compliance
Check again between 2-4 months
Once normal, continue for 3 months to replenish all stores then stop
Monitor FBC every 3/12 for 1yr
What foods can increase iron intake?
Green leafy veg - cabbage, broccoli, kale, turnip greens, collard greens
Legumes - black eyed beans, pinto beans, peas. lima beans
Iron enriched grains, pastas, cereals
Meat - especially organs such as liver
Poultry - again especially dark meat
Fish - esp. shellfish, anchovies
What other investigations might be required if iron deficiency anaemia is diagnosed?
It is important to investigate all new iron deficiency anaemia - will depend on risk factors and other key features in the Hx - to ensure serious pathology is not missed (e.g. GI Ca)
Faeces sample - occult blood
Urine dip - for blood
GI abnormalities - scopes up and down
Gynae evaluation - e.g. pelvic USS, uterine biopsy
Appropriate referrals should be made
How do you manage severe iron deficiency anaemia?
May need IV iron infusion(s):
- If symptomatic e.g. SOB, dizziness, syncope
- Are unable to absorb or adhere to oral iron regimens
If Hb below 70g/L - may need restrictive red cell transfusion (aiming for 70-90g/L after)
