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)

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