Acquired Anaemias Flashcards
Firstly define Anaemia
A haemoglobin below the normal range for Age/Sex/Ethnicity
What are the clinical features of anaemia
Think poor perfusion: - Fatigue - SOB - Ankle Swelling - Dizziness - Chest Pain Symptoms of the cause
What is your first test when suspecting anaemia?
A FBC
Tells you the haemoglobin and the MCV/MCH
How do we describe anaemias?
Morphologically based on MCH & MCV
1) Hypochromic, Microcytic
2) Normochromic, Normocytic
3) Macrocytic
FBC shows hypochromic, microcytic anaemia, what are the likely causes?
Most likely Fe-deficiency Anaemia, if you’re in any doubt do a serum Ferritin to check (should be low)
If Ferritin is fine then it may be a secondary anaemia or Thalassaemia
Fe-deficiency anaemia is not a diagnosis but must have a cause, what could cause it?
Malabsorption e.g. gastritis or coeliac
Blood loss e.g. GI or menorrhagia
What elements of a history/exam could suggest iron deficiency anaemia?
Evidence of bleeds e.g. dyspepsia, PR bleeding or menorrhagia
Diet (in kids/elderly)
Pregnancy (increases Fe need)
Koilonychia, atrophic tongue & angular stomatitis
Also do Abdo & rectal exam looking for the cause
What tests can we do if we get a case of Fe-deficiency anaemia?
Endoscopy & barium study can be done if there’s evidence of GI blood loss
How do you treat Fe-deficiency anaemia?
Oral Iron +/- transfusion
Treat the cause
Patient presents with a Normochromic, normocytic anaemia, how would you proceed?
Test their Reticulocyte count.
If it’s increased it means you’re losing RBCs and the marrow is compensating –> Blood loss of haemolysis
If its normal or low –> Secondary anaemia, marrow infiltration etc
So lets say this patient’s reticulocyte count is high and you suspect a haemolytic anaemia. What could cause that?
Autoimmune HA (Extravascular haemolysis)
Or an intravascular cause:
- Mechanical e.g. art valve leaking
- Severe inf
- Pre-eclampsia, HUS or DIC
- Drugs
Congenital causes e.g.:
- G6PD deficiency
- Hereditary Spherocytosis
- Haemoglobinopathies e.g. Sickle cell
So we’ve done a FBC (normocytic/chromic) & a reticulocyte count (high).
How would we test a patient to see if they’re haemolysing?
Blood film = can see haemolysed cells
Serum Bilirubin = High
LDH = High
Serum Haptoglobin = low (eats up free haemoglobin)
How would we identify the cause of a haemolytic anaemia?
Coomb’s Test:
Detects Ab/complement on the red cell membrane so if +Ve suggests an immune source
Can also test urine for Haemosiderin & Urobilinogen
- Haemosiderinuria in intravascular haemolysis
- Extravascular haemolysis increases serum bilirubin –> high Urobilinogen
What can trigger an auto-immune haemolytic anaemia and how does coomb’s test help us with that?
Auto-antibodies from different triggers will agglutinate at different temperatures in coomb’s test so:
- Warm temps = idiopathic, drugs or CLL
- Cold Temps = CHAD, infection or lymphoma
How would we manage a haemolytic anaemia?
Support the marrow with Folic Acid
~Transfusion
Correct cause:
- IV Abx if septic
- Prosthetic valve replacement if leaky
- Immunosuppression & treat trigger if immune
Can also remove the site of haemolysis i.e. spleen
