Anaemia — Viva

Q1: "Classify anaemia" (2 min)

Two complementary systems.

• Morphological (MCV): microcytic (under 80 — iron deficiency, thalassaemia, ACD, sideroblastic, lead), normocytic (80 to 100 — acute loss, ACD, haemolysis, aplastic, marrow infiltration, mixed deficiency), macrocytic (over 100 — megaloblastic B12/folate vs non-megaloblastic alcohol/liver/hypothyroid/MDS/reticulocytosis).
• Kinetic (reticulocyte count / RPI): underproduction (low retics — substrate deficiency, marrow failure, ACD) vs destruction/loss (high retics — haemolysis, blood loss).

Q2: "How would you investigate a normocytic anaemia?" (3 min)

First, reticulocyte count. High retics → haemolysis/loss (LDH, haptoglobin, bilirubin, DAT, film for schistocytes/spherocytes; assess for bleeding). Low retics → underproduction (U&E/CKD-EPO, LFTs, TSH, CRP/ESR, HIV, B12/folate, marrow aspirate/trephine if pancytopenia or unexplained). Always also examine the peripheral film and check iron studies (early iron deficiency is normocytic).

Q3: "Discuss the treatment of iron deficiency anaemia — including failure to respond" (3 min)

Oral ferrous sulphate 200 mg TDS for 3 to 6 months after Hb normalises; expect reticulocytosis at 7 to 10 days and Hb rise 10 to 20 g/L per fortnight. If no response: check (1) ongoing blood loss exceeding replacement (re-assess GI/menorrhagia), (2) wrong diagnosis (thalassaemia, ACD, sideroblastic), (3) non-adherence/malabsorption (coeliac, H. pylori, atrophic gastritis, post-bariatric), (4) mixed deficiency (need B12/folate too), (5) concomitant inflammation blocking iron use. Switch to IV ferric carboxymaltose 1000 mg if oral is intolerated or malabsorption confirmed. Always investigate the cause — iron deficiency in a man/post-menopausal woman is GI blood loss until proven otherwise (coeliac serology, OGD, colonoscopy). [1]

Q4: "A patient has macrocytic anaemia with paraesthesia and ataxia. Discuss." (2 min)

B12 deficiency with subacute combined degeneration of the cord (dorsal + lateral columns — loss of vibration/proprioception, sensory ataxia, Romberg positive, spastic paraparesis, extensor plantars). Confirm with serum B12 (and methylmalonic acid/homocysteine if borderline — MMA raised only in B12, not folate). Treat urgently before damage is fixed: IM hydroxocobalamin 1 mg daily or on alternate days; continue until no further improvement, then 1 mg every 2 to 3 months for life (pernicious anaemia). NEVER give folate alone — precipitates/worsens the myelopathy. Check intrinsic factor antibodies (pernicious), screen for autoimmune cluster (thyroid, Addison's), and arrange gastroscopy (increased gastric cancer risk). [1]

Q5: "What are the transfusion thresholds in anaemia?" (2 min)

Restrictive strategy (TRICC, FOCUS): Hb under 70 g/L in a stable adult; under 80 g/L with symptoms, cardiac disease, or in the elderly/peripoperative; rarely under 100 in acute coronary syndrome. Single-unit prescribing in older/vulnerable patients with reassessment between units. Avoid transfusing chronic iron deficiency (risks without benefit). In massive haemorrhage, activate the massive transfusion protocol — group O negative for women of childbearing potential. Beware TACO (circulatory overload — slow infusion, diuretic cover) and TRALI. [1]

References

1. [1]Pavord S, Myers B, Robinson S, Allard S, Strong J, Oppenheimer C; British Committee for Standards in Haematology. UK guidelines on the management of iron deficiency in pregnancy. Br J Haematol, 2012.PMID 22512001