classification and features of anaemia

Question 1

When is a person said to have anaemia

Answer 1

when the total hb count is less than what is expected for a person of a certain age,gender,and geographical location.

Question 2

How does geographical location affect hb?

Answer 2

higher altitudes present with less oxygen.

people who reside in such areas will develop increased rbc ‘s in order to carry more oxygen.

Question 3

Is anaemia a disease?

Answer 3

Anaemia is not a disease in itself, it is usually secondary to a disease.

Question 4

General pathophysiology of anaemia

Answer 4

decreased hb/rbc–>decreased O2 carrying capacity–>hypoxia or hypoxia induced effect on organ –>signs of anaemia

Question 5

classification of anaemia

Answer 5

Aetiologic

based on morphology

Question 6

aetiologic causes of anaemia include

Answer 6

blood loss

low production of rbc

excessive destruction of rbc

Question 7

Morphologic classification of of anaemia

Answer 7

Macrocytic anaemia
Microcytic hypochromic
Normocytic normochromic

Question 8

what causes impaired RBC production

Answer 8

1. lack of nutrients required for erythropoiesis ie folic acid, iron,vit B12
2. Bone marrow failure causing decreased erythropoietin activity
3. Anaemia cause by chronic conditions, i.e infections, kidney dx ,inflammatory disorders, connective tissue disorders
4. Aplastic anaemia
5. Anaemia from replacement of bone marrow. i.e in leukemia or lymphoma

Question 9

Types of defects in RBC that cause anemia

Answer 9

1. intrinsic defect in RBC ie membrane/Hb
   Congenital ; hereditary spherocytosis, elliptocytosis ;sickle cell, thalassemia, unstable hb dx; pyruvate kinase deficiency, g6pd deficiency
   Acquired ; paroxysmal nocturnal hemoglobinuria
2. Extrinsic defects
   immune mechanisms; autoimmune acquired hemolytic anaemia;hemolytic dx of the newborn; March hemolytic anaemia

Question 10

Acquired intrinsic defect that destroys RBC

Answer 10

Paraxosymal nocturnal haemoglobinuria

Question 11

All extrinsic defects are

Answer 11

acquired

Question 12

Paraxosymal nocturnal haemoglobinuria is

Answer 12

loss of protein on RBC that prevents it from being attacked by complement

Question 13

Morphologic classification is based on

Answer 13

size

Hb content of RBC

Question 14

Size of rbc

Answer 14

8 microns in diameter

Diameter comparable to the nucleus of a mature lymphocyte

Question 15

What is it called when the size of RBC is normal

Answer 15

Normocytic

Question 16

When the size of RBC is smaller than normal

Answer 16

microcytic

Question 17

Diameter of RBC is bigger than normal

Answer 17

Macrocytic

Question 18

when Hb content of RBC is normal

Answer 18

Normochromic

Normochromic RBCs have an area of central parlor 1/3 its size

Question 19

Hb content lower than normal

Answer 19

Hypochromic

Question 20

What is mean cell volume

Answer 20

Average volume of RBC in blood

Question 21

Formula to calculate mean cell volume

Answer 21

Hematocrit %
………………………….. *10
RBC *10 raised to the power 12 /L

Question 22

Unit for mean cell volume

Answer 22

femtolitre

Question 23

Normal range of mean cell volume

Answer 23

81-100fL

Question 24

What is mean cell haemoglobin

Answer 24

Average weight of hb in RBC

Question 25

Formula for mean cell haemoglobin

Answer 25

Hbg/dl ------------ * 100 Hematocrit %

Question 26

Unit of mean cell haemoglobin

Answer 26

Picograms

Question 27

Normal range of mean cell haemoglobin

Answer 27

26-34pg

Question 28

what is mean cell hb concentration

Answer 28

Average concentration of hb in RBC volume

Question 29

Formula for mean cell hb concentration

Answer 29

hb g/dl ------------------- *100 hematocrit %

Question 29

Formula for mean cell hb concentration

Answer 29

hb g/dl ------------------- *100 hematocrit %

Question 30

unit for mchc

Answer 30

grams per deciliter

Question 31

Range for mchc

Answer 31

31-36 g/dl

Question 32

What does hematocrit mean

Answer 32

fraction of volume of blood that red blood cells occupy

Question 33

hematocrit in males

Answer 33

46%

Question 34

Hematocrit in females

Answer 34

42%

Question 35

Red cell distribution width

Answer 35

Checks range in volume and size of RBC. Low value means cells are uniform high value shows cells vary in size, usually due to presence of young RBC which are usually large. occurs in i.e pernicious anaemia; iron deficiency anaemia

Question 36

Range for red cell distribution width

Answer 36

11.5%-14.5%

Question 37

poikilocytosis

Answer 37

A condition where a number of RBCs are abnormally shaped

Question 38

Formula for red cell distribution width

Answer 38

standard deviation of MCV .................................................. *100 MCV

Question 39

Normocytic Normochromic anaemia

Answer 39

Characterized by normal MCV,MCH,MCHC

Question 39

Normocytic Normochromic anaemia

Answer 39

Characterized by normal MCV,MCH,MCHC

Question 40

Normocytic Normochromic anaemia

Answer 40

Characterized by normal MCV,MCH,MCHC

Question 41

Conditions where you'll find normocytic normochromic anemia

Answer 41

``` Aplastic anemia increased plasma volume i.e in pregnancy,overhydration Blood loss kidney dx Anemia due to chronic disease ```

Question 42

Microcytic hypochromic anemia

Answer 42

Characterized by low MCV,MHC,MCHC

Question 43

Conditions associated with microcytic hypochromic anemia

Answer 43

thallasemia | lead poisoning

Question 44

Macrocytic anemia

Answer 44

Characterized by raised MCV

Question 45

Conditions where Macrocytic anemia occurs

Answer 45

Megaloblastic anemia; where bone marrow forms abnormally huge rbcs due to deficiency of folic acid or vitamin b12

Question 46

Approach to anemic patient

Answer 46

``` take good history color of urine history in family examination of patient request appropriate investigations ```

Question 47

History includes

Answer 47

``` diet number of pregnancies menorrhagia dark urine unusual bleeding family history of anemia ```

Question 48

Physical examination includes

Answer 48

``` koilonychia of nails pallor of mucus membrane Examine mouth for glossitis or any lesions pedal edema jaundice check abdomen for masses/organs ```

Question 49

Investigations include

Answer 49

1. Reticulocyte count -high amounts mean RBCs are being depleted whiles low amounts mean theres a problem with bone marrow 2. sickling test and Hb electrophoresis 3. Blood film - RBCs stained for spherocytes etc 4. coombs test for antibodies 5. Thick and thin blood film for malaria and other infections 6. G6PD test 7. ESR and CRP test ; elevated in inflammatory conditions and plasma cell myeloma