Anaemia

Question 1

Anaemia definition

Answer 1

A reduction in concentration of circulating haemoglobin or oxygen carrying capacity of blood below the level that is expected for healthy persons of same age and sex in the same environment

Question 2

Normal hb levels

Answer 2

WHO
Males: <13g/dl
Females: <12g/dl

Africa : <10g/dl

Question 3

Reference ranges

Answer 3

•Also called reference interval.
•Range of values deemed normal for a physiologic measurement in healthy persons.
•Derived from apparently healthy persons in a given population.
•It takes into account age, sex and geographical location (environment).
•Values within the reference range are described as “within normal limits”.

Question 4

How are reference ranges obtained

Answer 4

Samples are taken from an apparently healthy population
•The values obtained are computed
•Normal distribution of the measured parameters are assumed.
•The mean is calculated
•2 standard deviations (SD) on either side of the mean are also obtained.
•± 2 SD on either side of the mean encompasses 95% of the general population

Question 5

Reference range of a particular measurement

Answer 5

reference range of a particular measurement is the interval between which 95% of values of a reference population fall into.

MEAN – 2 S.D = Lower reference limit
•MEAN plus 2 S.D = Upper reference limit
•Values within the reference range are described as “within normal limits”
•Values below the lower limit of normal are described as “low”
•Values above the upper limit of normal are described as “high”

Question 6

PCV values

Answer 6

Males- 40-52%
Females- 36- 48%

Question 7

Hb values

Answer 7

Males- 13.5-17.5g/dl
Females- 11.5- 15.5g/dl

Question 8

Rbc indices

Answer 8

These are part of complete blood count tests that are used to check for anaemia,
They check the size, shape and hb conc. of the rbcs
They include:
-mcv
-mhc
-mchc
-rdw

Question 9

MCV

Answer 9

mean cell volume
It describes the size of a rbc
It is directly proportional to the size of the rbc
It is measured in fentolitres(fl)
The normal value is 80-95 fl.
It is also called mean corpuscular volume

Question 10

MCH

Answer 10

Mean cell hb
It measures the weight of hb in a rbc
It is measured in picograms(pg)
The normal value is 27-34pg

Question 11

MCHC

Answer 11

Mean cell hb conc.
It measures hb weight in relation to volume
It is measured in g/dl.
Normal value is 30-36g/dl

Question 12

RDW

Answer 12

Red cell distribution weight
It measures the variation in the size of rbcs
It measures the degree of anastocytosis
Normal value is 11-15%

Question 13

RDW

Answer 13

Red cell distribution weight
It measures the variation in the size of rbcs
It measures the degree of anastocytosis
Normal value is 11-15%

Question 14

Anastocytosis

Answer 14

This refers to the variation in rbcs
It is measured using RDW.

Question 15

Poinkilocytosis

Answer 15

This is the variation in shape of rbcs
There is no particular index that measures it but RDW gives an insight.

Question 16

Reticulocyte count

Answer 16

Also called absolute reticulocyte count
Normal value is 50-150 * 10^9/L

Question 17

Platelet count

Answer 17

Western value- 150-400 10^9/L
Africa- 100-38010^9/L

Question 18

WBC count and differentials

Answer 18

WBC - 4.0-11.0 *10^9
Neutrophils- 40-60%
Lymphocytes- 20-40%
Monocytes- 2-8%
Eosinophils- 1-4%
Basophils- 0.5-1%

Question 19

Classification of anemia

Answer 19

Aetiology: due to
-impaired red cell production
-excessive red cell destruction (haemolytic anaemias)
-excess blood loss

•Morphology: based on red cell indices
-Macrocytic
-Microcytic
-Normocytic

Presence or absence of clinical features
-speed of onset
-age
-haemoglobin O2 dissociation curve

•Severity: based on PCV levels
-Mild (>27-30%)
-Moderate (21-27%)
-Severe (<21%)

Question 20

Macrocytic anemia causes

Answer 20

Megaloblastic causes
- vit. B12 deficiency
-folate deficiency
Non- megaloblastic causes
- myeloma
-alcoholism
- liver disease
- aplastic anemia
- myxodema
- cytotoxic therapy
- reticulocytosis
-smoking

Question 21

Clinical features- symptoms

Answer 21

•Shortness of breath (dyspnea), usually on exertion
•Easy fatiguability
•Body weakness
•Palpitations
•Headache
•Dizziness
•Lethargy

Question 22

Clinical feature - signs

Answer 22

Pallor
•Jaundice (+/-)
•Tachycardia
•Full volume, bounding pulse
•Displaced apex beat indicative of cardiomegaly (+/-)
•Third heart sound, S3 (+/-)
•Pan-systolic murmur
NB: Specific signs would be treated under specific anaemias

Question 23

Investigations

Answer 23

Full blood count and differentials
•Red cell indices
•Reticulocyte count
•Blood film
•Haemoglobin electrophoresis
•Coombs Test (Antiglobulin test)
•Bone marrow aspiration and biopsy
•Iron studies
•Vitamin B12/ folate assays
•Enzyme assays