1: Diagnostic approach to anaemia Flashcards
What is anaemia
Deficiency in haemoglobin
How can anaemia be classified
- By aetiology
2. Morphology
What is required to classify anaemia by morphology
FBC: Hb, MCV, MCHC
What defines anaemia in males
Hb < 135
What defines anaemia in females
Hb <115
What defines anaemia in the first-trimester of pregnancy
Hb < 110
What defines anaemia in the second or third trimester of pregnancy
Hb <105
Remember 2 + 3 trimester = 5
What defines post-natal anaemia
Hb < 100
After investigating for anaemia, what is performed next
MCV
What MCV defines microcytic anaemia
Less-than 80
What is a mnemonic to remember causes of microcytic anaemia
TINS
What are the 4 causes of microcytic anaemia
Thalasemia
IDA
Normocytic anaemia/ anaemia chronic disease (initially)
Sideroblastic
What MCV defines normocytic anaemia
80-100
What is a mnemonic to remember causes of normocytic anaemia
HARP-B
What are the causes of normocytic anaemia
Hypothyroidism (or microcytic) Haemolysis (or microcytic) Anaemia of chronic disease Renal failure Pregnancy Bone marrow failure
What MCV defines macrocytic anaemia
> 100
What is the mnemonic to remember macrocytic anaemia
MR.CRAB
What are the causes fo macrocytic anaemia
MDS or myeloproliferative Reticulocytosis Cytotoxic drugs (hydroxycarbamide) Relatively low thyroid Anti-folate medications (methotrexate, phenytoin, trimethoprim) B12 or folate deficiency
If a person has microcytic anaemia, what should be looked at next
Ferritin
What does a microcytic anaemia, with low ferritin indicate
IDA
explain transferrin saturation in IDA
Transferrin saturation will be low. As low iron means less RBC and therefore less sites on transferrin occupied
explain TIBC in IDA
TIBC will be high. As less RBC, there will be more spaces on transferrin to be occupied by RBC
explain RDW in IDA
Wider - as more RBC produced
how will reticulocyte count present in IDA
Decreased - as insufficient iron to produce RBC
how will the following present in IDA:
a. Ferritin
b. TIBC
c. Transferrin saturation
d. RDW
a. Low
b. High
c. Low
d. High
If microcytic anaemia, ferritin is normal - what is looked at next
TIBC
if TIBC is low in microcytic anaemia and ESR/ CRP is high, what does it likely indicate
Anaemia of chronic disease (early stages)
If TIBC is low in microcytic anaemia and Hb electrophoresis is abnormal what does it likely indicate
Thalasemia
What is a characteristic feature of sideroblastic anaemia
Basophilic stippling
How will the following present in thalassemia
a. Ferritin
b. Transferrin saturation
c. TIBC
d. RDW
a. Normal
b. Normal
c. Low
d. Normal
How will the following present in anaemia of chronic disease
a. Ferritin
b. Transferrin
c. TIBC
d. RBW
a. High
b. Low
c. Low
d. Normal
How will the following present in sideroblastic anaemia
a. Ferritin
b. Transferrin saturation
c. TIBC
d. RDW
a. High
b. High
c. Low
d. High
If an individual has normocytic anaemia what should be looked at next
reticulocytes
If reticulocytes are high, what is looked at
EPO
if reticulocytes are high, EPO low, what is the likely cause
- CKD
If reticulocytes are high, EPO high, what is the likely cause
- Aplastic anaemia
if reticulocytes are low what is looked at
Markers of haemolysis
what are signs of haemolysis
- Low haptoglobin
- High LDH
what does no signs of haemolysis indicate
Blood loss
what do signs of haemolysis indicate
Haemolytic anaemia
what is performed if megaloblastic anaemia
Peripheral Blood Smear
what causes a megaloblastic macrocytic anaemia
- B12 Deficiency
- Folate Deficiency
what causes a non-megaloblastic macrocytic anaemia
- Reticulocytosis
- Multiple myeloma
- Alchoholism
- MDS
- Hypothyroidism
what do symptoms of anaemia depend on
- Fall in Hb
- Rate of fall in Hb
what are symptoms of anaemia
- Lethargy
- Dizziness
- Syncope
- Dyspnoea
- Pallour
- Palpitations
- Angina - if predisposing coronary artery disease
what are 4 signs of anaemia
- Conjunctival pallour
- Kolonychia
- Angular stomatitis
- Glossitis
how may a Hb below 80 present
Bounding pulse, Tachycardia, Postural Hypotension
when are Howell-jolly bodies seen on peripheral blood film
Hyposplenism: Coeliac, Sickle Cell, Crohn’s
Post-Splenectomy
what are pappenherimer bodies
granules of siderocytes containing iron
when are pappenheimer bodies seen
- Lead-poisoning
- Post-splenectomy
what is poikilocytes
variation in RBC shape and size
when are poikilocytes seen
IDA
what is rouleaux formation
when RBC aggregate together
when is rouleaux formation seen
multiple myeloma
what are schistocytes
fragments RBC
what causes schistocyte formations
intra-vascular haemolysis
what are spherocytes
spherical shaped
what causes spherocytosis
Hereditary spherocytosis
what are target cells
RBC with central stain, ring of pallour and outer staining
when are target cells seen
- Liver disease
- Hyposplenism
- Thalasemia
- IDA
what are tear-drop RBC characteristic of
myelofibrosis
what do Heinz bodies indicate
G6PD deficiency
Thalasemia
what are hyperhsegmented neutrophils characteristic of
Megaloblastic anaemia
if sideroblastic anaemia is suspected what is used to stain the bone marrow biopsy
prussian blue staining
