Question 15.2

College answer

Syllabus topic/section:

2.1.13    Haematological and Oncological Intensive Care: Anaemia: L1

Discussion: 

Some candidates identified the specific abnormalities correctly, but did not explain their rationale nor identify the unifying abnormality of iron deficiency anaemia.

Candidates often listed 2 different forms of the same pathology/causative factor (eg blood loss from both phlebotomy and surgical bleeding) or incorrect causative factors (iron removal by dialysis which does not cause iron deficiency because of the extremely small amount of elemental iron ions available for diffusion) rather than 2 different causative factors.

In the treatment section incorrect strategies were included by some, for example GCSF which is not a treatment for iron deficiency anaemia and EPO even though the EPO level in the stem was already elevated.

Many candidates also reflexively listed the advantages of the iron replacement strategies in their answer to part c), even though the question specifically asked for disadvantages and/or risks. Candidates are reminded to ensure they read the question carefully to ensure they are answering the question directly and not wasting time on providing information that unfortunately doesn’t attract marks.
 

Discussion

a) This is anaemia of iron deficiency

• Anaemia
• Low serum ferritin, suggesting poor iron stores
• Low serum iron
• Raised TIBC and low transferrin saturation, suggesting if there was iron around, there'd be plenty of proteins available to carry it
• A raised erythropoietin level (which is actually normal, because this is a completely appropriate reaction to anaemia)

a) only two causative factors?

• Endometrial carcinoma tends to present with PV blood loss, so there would have been pre-operative iron loss already
• The surgery itself is described as "extensive", meaning might have been some kind of horrific bloodbath, or possibly complicated by mishaps (eg. the surgical notes meticulously document the repair of a common iliac artery)
• The long ICU stay suggests further surgical problems (perhaps related to blood loss?)
• Long ICU stay tends to be associated with frequent blood sampling, which is an iatrogenic source of blood loss
• The acute kidney injury may have resulted in poor EPO secretion, except they gave us the EPO level and it is actually appropriately elevated, which raises the question: why did they mention the acute kidney injury in the stem? Nothing is accidental. Most likely somebody complained that the stem was without meat.
• A reader (thanks Vinay!) has pointed out that malnutrition and hepcidin-upregulation-related poor gut absorption of iron could also be responsible for the anaemia

c)

The management options include:

• Red cell transfusion (obviously)
  • Risks of transfusion reaction and circulatory overload
• Iron infusion 
  • Anaphylaxis is a potential risk
  • May want to wait until all the infectious complications are behind us as well
• Iron supplementation
  • Risks is in the constipation they cause, as well as the inherent slowness of correction
• Minimisation of losses (rationalised blood sampling, use of paediatric tubes)
  • Risk is the possibility that decreased sampling will miss abnormalities