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
Moderate
- Shortness of breath at rest
- Palpitations
Mild
- Fatigue
- Shortness of breath on exertion
Relevant history
Bleeding history
- Menstrual history
- Previous surgery
- Dental extraction
- Epistaxis
- Mucocutaneous bleeding
GI blood loss
- Change in bowel habit, dyspepsia, melaena
Haemolysis
- Jaundice, urinary symptoms
Bone marrow pathology
- B-symptoms
Underlying malignancy
- Malaise
- Weight loss
Social history
- Diet: vegan/vegetarian, dietary content
- Medications
- Alcohol history
Medical history
- Autoimmune diseases
- Inflammatory bowel disease
- Anaemia/transfusion/iron
Family history
- Bleeding, anaemia, malignancy
INVESTIGATIONS
- Review previous laboratory results
- screening bloods already performed?
- Always send tests before treatment/transfusion
All anaemic patients
- FBC, reticulocyte count and blood film
- U&E, liver function, bone profile
- Ferritin
- Serum B12 (cobalamin)
- Serum folate
- TSH
Patients with ferritin <100 and raised CRP or chronic inflammatory disorder/infection
- Transferrin saturations
Patients with eGFR <60
- Percentage hypochromic red cells (%HRC)
- performed as part of the FBC. phone lab for result
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
- Urine electrophoresis (BJP)
Any patient who may require a blood transfusion in next 7 days
- Group & screen (G&S)
INTERPRETATION OF RESULTS
MCV
Is MCV either:
Microcytic & Hypochromic
Interpretation
- Iron deficiency
- Anaemia of chronic disease (ACD)
- Haemoglobinopathies
- ? Sideroblastic anaemia
- ? Lead poisoning
Potential tests/actions
- Review ferritin results +/- transferrin saturations
- Haemoglobinopathy screening
- Lead levels
- Bone marrow aspirate/trephine. Refer to haematology
Macrocytic
Interpretation
- Megaloblastic; B12 or folate deficiency
- Drugs:
- MTX, 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 tests/actions
- See B12 deficiency and/or folate deficiency guidelines
- Review drug SPC’s
- Bone marrow aspirate/trephine - refer to haematology
- GGT/USS abdomen/liver screen. Discuss with gastroenterology
- Haemolysis screen. If positive - refer to haematology
- ? Pregnancy test
Reticulocyte count
%age reticulocytes increased
Interpretation
- Natural response to anaemia
- acute blood loss
- haemolytic anaemia
Potential 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 tests/actions
- As dictated by history and lab results
- Potentially bone marrow aspirate/trephine - refer to haematology
Blood film
Interpretation
- Morphology may indicate underlying cause of anaemia
- iron deficiency
- megaloblastic anaemia
- 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
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 tests/actions
- Review ferritin
- Check if %HRC >6%
- Consider myeloma screen
eGFR <30 mL/min/1.73m2
Interpretation
- Anaemia may be due to CKD
Potential tests/actions
- Review ferritin
- Check if %HRC >6%
- Refer to renal team for consideration of IVFe/EPO
- Consider myeloma screen
Percentage hypochromic red cells (%HRC)
- If known renal patient, reported as part of FBC
- Interpret with ferritin/U&E/Hb
- Aim < 6%
- Consider iron supplementation
- Liaise with renal team
Ferritin
Absolute iron deficiency (Ferritin < 15ng/mL)
Likely absolute iron deficiency (Ferritin 15-30ng/mL)
Possible absolute iron deficiency (Ferritin 30-100ng/mL)
- Check transferrin saturations
- if < 20%, see Iron deficiency
Normal/ raised Ferritin with infectious, inflammatory and malignant disease or CKD
Interpretation
- Potential functional iron deficiency due to iron restricted erythropoiesis
- In patients with CKD, review %HRC
Cobalamin/B12
Cobalamin/B12 normal/reduced
- Interpret by history and medications
- See B12 deficiency
Cobalamin/B12 > 600pmol/L
- Iatrogenic
- Cancers
- haematological e.g. MPN, CML, AML
- weaker link with non-haem cancers and even as yet diagnosed cancers
- Liver disease
- Manage as clinical history
Serum Folate
- If serum folate <3, consider folate deficiency
MANAGEMENT
- Treat the underlying cause
- Optimise medical co-morbidities, especially in ACD
RBC transfusion in chronic anaemia
- Consider a single unit RBC transfusion in patients with:
- moderate/severe symptoms
- haemodynamically stable
- reversible cause of anaemia
- Hb <90 g/L
- Remember each unit transfused is a treatment decision
Transfuse or not?
After each 1-unit transfusion
- Reassess symptoms of anaemia
- Check for signs of fluid overload
- Repeat Hb (Hb target achieved?)
Further transfusion?
DISCHARGE
- See individual guidelines
- Arrange appropriate further investigations and results are followed-up
- Refer to haematology or relevant specialities
- In discharge letters, provide full details of investigation, diagnosis, treatment and frequency of subsequent monitoring
© 2022 The Bedside Clinical Guidelines Partnership.
Created by University Hospital North Midlands and Keele University School of Computing and Mathematics.
Research and development team: James Mitchell, Ed de Quincey, Charles Pantin, Naveed Mustfa