RECOGNITION
- Anaemia (WHO):
- Hb <130 g/L in males
- Hb <120 g/L in non-pregnant females
- normal range for Hb includes patients who are anaemic
- Look for cause
Symptoms
- Patients may tolerate very low Hb levels
- do not base clinical decisions on Hb value alone
Severe
- Heart failure symptoms
- Chest pain
- Shortness of breath at rest
Moderate
- Shortness of breath on minimal exertion
- Frequent palpitations
Mild
- Fatigue
- Shortness of breath on exertion
Relevant history
Bleeding history
- Menstrual history
- GI blood loss, dyspepsia, melaena
- Previous surgery
- Dental extraction
- Epistaxis
- Mucocutaneous bleeding
Haemolysis
- Jaundice, urinary symptoms
Bone marrow pathology
- B-symptoms
Underlying malignancy
- Change in bowel habit
- Malaise
- Weight loss
Social history
- Diet: vegan/vegetarian, dietary content
- Medications
- Alcohol history
Medical history
- Autoimmune diseases
- Inflammatory bowel disease
- Bariatric surgery
- Anaemia/transfusion/iron
Family history
- Bleeding, anaemia, malignancy - especially bowel cancer
INVESTIGATIONS
- Review previous laboratory results
- Check if screening bloods already performed
- Always send tests before treatment/transfusion
ALL anaemic patients
- FBC and blood film
- Reticulocyte count (and calculate reticulocyte index)
- U&E, liver function, bone profile
- Ferritin, transferrin saturation
- Serum B12 (cobalamin) if normal in last 6-12 months, repeat may be unnecessary
- Serum folate
- TSH
Patients with eGFR <60
- Percentage hypochromic red cells (%HRC) – if processed within 6 hr of collection
- performed as part of the FBC. phone lab for result
- If haematinic deficiency excluded, consider
- immunoglobulins (Ig) and serum electrophoresis (unnecessary if normal within past 12 months)
- serum free light chains (unnecessary if ratio normal within past 12 months)
Jaundice/haemolysis suspected
- Lactate dehydrogenase (LDH)
- Haptoglobin
- Direct antiglobulin test (DAT)
- positive results are often found in ill patients in hospital without haemolysis
- Split bilirubin (Conj/unconj)
Anaemia with hypercalcaemia
- Immunoglobulins (Ig) and serum electrophoresis
- Serum free light chains
Any patient who may require a blood transfusion in next 7 days
- Group and screen
INTERPRETATION OF RESULTS
Interpretation of MCV
Is MCV either:
Microcytic & Hypochromic
Interpretation
- Iron deficiency anaemia
- Anaemia of chronic disease (ACD)
- Haemoglobinopathies
- ? Sideroblastic anaemia
- ? Lead poisoning
Potential additional tests/actions
- Review ferritin results +/- transferrin saturations
- Haemoglobinopathy screening (Hb electrophoresis)
- Consider lead levels
- Bone marrow aspirate/trephine (refer to haematology)
Macrocytic
Interpretation
- Megaloblastic; B12 or folate deficiency
- Drugs:
- Methotrexate, azathioprine
- cyclophosphamide (typical MCV105–115 fL)
- hydroxycarbamide (typical MCV <135 fL)
- Alcohol (typical MCV 100–110 fL)
- Liver disease (typical MCV <115 fL)
- Haemolysis (typical MCV 100–130 fL)
- ? Bone marrow disorders e.g. myelodysplasia
- ? Pregnancy (typical MCV <105 fL)
- ? Hypothyroid (typical MCV <110 fL)
Potential additional tests/actions
- See B12 deficiency and/or folate deficiency guidelines
- Review drug SPC’s
- Haemolysis screen (refer to haematology if positive)
- ? Pregnancy test
- Bone marrow aspirate/trephine (ref haematology)
- GGT/USS abdomen/liver screen (discuss with gastro)
Interpretation of blood film
Interpretation
- Morphology may indicate underlying cause of anaemia
- iron deficiency
- megaloblastic anaemia
- haemolysis
- bone marrow pathology e.g. dysplasia, acute leukaemia
Potential tests/actions
- If bone marrow pathology identified, liaise acutely with haematology on call
- If leucoerythroblastic film (LEBF) identified, review clinical history
- liaise as appropriate
Interpretation of reticulocyte count
%age reticulocytes increased
Interpretation
- Natural response to anaemia
- blood loss (not acute)
- haemolytic anaemia
Potential additional tests/actions
- As dictated by history and lab results
%age reticulocytes normal or reduced
Interpretation
- Suggests an inappropriate or ineffective BM response to the anaemia
- ACD
- bone marrow failure (leukaemia, myeloma, infiltration by carcinoma etc.)
- haematinic deficiency
Potential additional tests/actions
- As dictated by history and lab results
- Potentially bone marrow aspirate/trephine - refer to haematology
Interpretation of eGFR
eGFR ≥ 60 mL/min/1.73m2
Interpretation
- Anaemia unlikely to be related to CKD
- Likely due to other causes
eGFR 30-60 mL/min/1.73m2
Interpretation
- Anaemia may be due to CKD
Potential additional tests/actions
- Review ferritin (see iron deficiency guidelines)
- ? %HRC >6% - if yes (and ferritin <800 ng/mL), trial of oral iron (see iron deficieny guideline)
- Consider myeloma screen
eGFR <30 mL/min/1.73m2
Interpretation
- Anaemia may be due to CKD (anaemia of chronic kidney disease)
Potential tests/actions
- Review ferritin (see iron deficiency guidelines)
- ? %HRC >6% and ferritin <800 ng/mL - trial of oral iron (see iron deficiency guidelines)
- Ensure myeloma screen undertaken. Consider referral to renal team for IVFe +/- EPO
Interpretation of percentage hypochromic red cells (%HRC)
- %HRC validated only in anaemia of CKD (A-CKD)
- Undertaken as part of FBC
- Valid if undertaken <6 hr of sampling
- Interpret with ferritin result/U&E/Hb
- Interpret only if anaemia of CKD
- If anaemia of CKD (A-CKD), aim <6%
- If A-CKD with %HRC >6%, offer trial of oral iron
- Liaise with renal team regarding IV iron +/- EPO
Interpretation of ferritin
- Absolute iron deficiency (Ferritin < 15ng/mL)
- See Iron deficiency guideline
- Likely absolute iron deficiency (Ferritin 15-30ng/mL)
- See Iron deficiency guideline
- Possible absolute iron deficiency (Ferritin 30-100ng/mL)
- Check transferrin saturations
- if < 20%, see Iron deficiency
Interpretation
- Potential functional iron deficiency (FID) (inappropriate iron utilisation) due to iron restricted erythropoiesis (IRE)
Potential additional tests/actions
- Review transferrin saturations
- In patients with CKD review %age HRC
Interpretation of Cobalamin/B12
Cobalamin/B12 > 600pmol/L
- Iatrogenic
- If patient receiving parenteral B12, do not monitor serum B12 supplementation
- Cancers
- haematological e.g. MPN, CML, AML
- weaker link with non-haem cancers and even as yet diagnosed cancers
- Liver disease
Potential additional tests/actions
- As per clinical history
Serum Folate
- If serum folate <3, treat folate deficiency
MANAGEMENT
- Treat the underlying cause of the anaemia
- Optimise medical co-morbidities, especially in acute coronary disease
- Do not transfuse haemodynamically stable patients with haematinic deficiency - give iron/B12/folate as appropriate - see investigation and management of iron/B12/folate deficiency guidelines
- If considering transfusion, see Red blood cell transfusion guideline
DISCHARGE
- See individual guidelines
- Arrange appropriate further investigations and ensure results are followed-up
- Arrange primary/secondary care follow up as appropriate
- In discharge letters, provide full details of investigation, diagnosis, treatment (including transfusion) and frequency of subsequent monitoring
Date updated: 2024-03-20