ANAEMIA Flashcards
Define Anaemia
State at which patient’s blood haemoglobin level is below the normal range for their age and sex.
range of Hb concentration for anaemia (in general, adult male, adult female, neonate, one year to puberty) .11.5-
If below 10 g/dl then anaemia.
Adult male = 13.5-17.5
Adult female = 11.5- 15.5
Neonate= 15-21
One year before puberty = 11-13.5
3 Causes of Anaemia ?
- Inc. blood loss.
- Inadequate RBC production.
- Excessive destruction of RBC .
4 Symptoms of Anaemia
- Easy fatiguability , weakness - breathlessness on exertion
- Headache
- Palpitations , inc. output of heart to compensate - skipped heart beat
- Angina - inc. output of heart to compensate - pain or uncomfortable feeling
4 Signs of a Anaemia
- Pallor of skin and mucous membrane
- Inc. heart rate ( tachycardia)
- Bound pulse
- Systolic flow murmur
Specific signs (approx. 4 each ) for each 4 types of Anaemia
- Fe deficiency - koilonychia ( spoon nails ) , glossitis( inflamed tongue ) , pica, poor cognitive function
- Megaloblastic anaemia - glossitis, Angular stomatitis ( inflammatory skin condition ) , mild jaundice , progressive neuropathy due to Vit B12 deficiency ( neurological abnormalities causing numbness in feet, difficulty in walking )
- Aplastic anaemia - recurrent infections, bleeding manifestations ( gum bleed , nose bleed)
- Haemolytic Anaemia - jaundice , haemoglobinuria ( high conc. Of haemoglobin in urine ), hepato - splenomegaly ( swelling of abdomen and liver )
What is polycythemia?
condition in which there is an absolute
increase in the number of circulating RBC
2 types of polycythemia ?
- Primary - polycythaemia rubra Vera . neoplastic disorder of haemopoietic stem cells (not due
to stimulation by erythropoietin) - Secondary – due to stimulation by erythropoietin ( a hormone secreted by the kidneys that increases the rate of production of red blood cells in response to falling levels of oxygen in the tissues.) – when
there is tissue hypoxia
4 groups of effects of polycythemia
1.dizziness, headache, blackouts
2.Plethoric ( full of body fluid ), reddened conjunctiva
3.Increased Hb, PCV ( packed cell volume),RBC – increased viscosity of blood
4.Bonemarrow - hypercellular
4 ways inc. blood loss causes Anaemia ?
Acute ( major blood loss ) ,
chronic ( hookworm infestation so chronic bleeding from intestinal walls ) ,
gastrointestinal bleeding ( peptic ulcer, NSAID, carcinoma of intestine),
uterine bleeding
Why and how does inadequate rbc production cause anaemia ?
deficiency of essential factors for erythropoiesis
( Iron, Vit B12, folic acid, erythropoietin)
- Problems in the bone marrow ( aplastic anemia )
a. Failure of haemopoietic stem cells and
reduction in the number of stem cells– Aplastic
anaemia – reduced number of RBC, WBC,
platelets (pancytopaenia)
b. Radiation damage
c. cytotoxic drugs, other drugs and toxins (viral
hepatitis) which destroy stem cells
d. Invasion of the bonemarrow – leukaemias,
fibrosis - Fe def anaemia
- Megaloblastic anaemia
2 types of Anaemia caused by inadequate production of RBC ?
- iron deficiency Anaemia
- megaloblastic Anaemia
Causes of iron deficiency Anaemia ?
Loss of iron due to blood loss
- chronic loss – hookworm infestation, GI
2. Inadequate intake
3. Malabsorption
4. States of increased demand
( pregnancy, infancy, lactation, menstuation )
Uniqueness of blood picture of iron deficiency anemia
hypochromic, microcytic red cells
Uniqueness of megalobalstic anaemia in blood picture
Macrocytes seen in blood picture ( larger and less likely to divide ) - Megaloblasts in bone marrow
What is megaloblastic Anaemia
In Vit B12 and folate deficiency
Causes of megaloblastic anaemia ?
Vit B12 deficiency
- Poor diet
– true vegetarians
- IF deficiency – pernicious anaemia (Pernicious anemia is a type of megaloblastic anemia in which the body isn’t able to absorb vitamin B12 due to a lack of intrinsic factor in stomach secretions. Intrinsic factor is needed for the body to absorb vitamin B12)
- Diseases of the ileum
Folate deficiency
- Inadequate diet - When body demand exceeds intake –
pregnancy
- Disease of the upper small intestine ( blood loss in the stomach or intestine cannot be matched by duodenal iron absorption, creating a negative iron balance)
What is Haemolytic anaemia ?
Anaemia due to excessive destruction of RBC
2 causes of haemolytic anaemia ?
intra-erythrocytic
extra-erythrocytic
5 Intra-erythrocytic causes ?
Hereditary
a. Congenital spherocytosis
- autosomal dominant inheritance
- defect in RBC membrane (deficiency of a
membrane protein) - spherocytes have increased osmotic fragility - haemolysis is extra-vascular
b.RBC enzyme deficiencies eg: G6PD deficiency - X- linked disorder (affecting males, carried by
females) - enzyme deficiency causes lack of production of
NADPH in red cells – causes the red blood cell
to be damaged by oxidants - Causes intra-vascular haemolysis with
haemoglobinuria eg. of oxidant agents – infections, drugs
(antimalarial, sulpha drugs)
c. Inherited disorders of haemoglobin (Haemoglobinopathies) – inherited disorders
characterized by defective synthesis of
polypeptide part of Hb
- Sickle cell anaemia
- Thalassemia
7 Extra- erythrocytic causes ?
Malaria
Drugs causing haemolysis
Immune disorders
Autoimmune haemolytic anaemia
Incompatible blood transfuions
Haemolytic disease of the newborn
Mechanical – artificial heart valves
What is Sickle cell anaemia ?
Haemoglobin S (HbS) – Beta chain is abnormal - Hypoxia causes polymerization (ppt) of HbS in
RBC – results in sickle shaped RBC – undergo
extravascular haemolysis - Sickle cells can block small vessels- ischaemic
bone pain, leg ulcers
What is Thalassaemias and 2 types ?
genetic disorders which result from reduced rate
of synthesis of alpha or beta chains
Alpha thalassaemia – no alpha chains , beta
chains B4 ppt. – causes haemolysis
Beta Thalassaemia – no beta chains –alpha chains ppt. – result in
haemolysis and ineffective erythropoiesis Hepato –splenomegaly is seen – due to increased
RBC destruction and extramedullary haemopoiesis ( leads to enlarged liver) Expansion of bones (bony deformities) is seen due
to marrow hyperplasia ( bone on end appearance )
General lab tests for anaemia?
Hb concentration, PCV, RBC count ( all 3 dec. if anaemia )
What do RBC indice ?
MCV – mean corpuscular volume (fL)
MCH – mean corpuscular haemoglobin (pg)
MCHC - mean corpuscular haemoglobin
concentration (g / dL)
Specific tests for Fe deficiency ?
serum iron levels
TIBC (total iron binding capacity - % saturation of
transferrin)
BM biopsy – for iron stores
Specific tests Haemolytic anaemias?
reticulocyte count, serum unconjugated bilirubin
Specific tests Congenital spherocytosis?
‘
osmotic fragility test
Specific tests Haemoglobinopathies?
Hb electrophoresis
What causes microcytic , hypochromic anemia ?
- Iron deficiency
- Thalassaemia
- Anaemia of chronic disease ( some cases )
- Lead poisoning
- Sideroblastic anaemia ( some cases ) ( coz of less rbc and too much iron in system )
What are 6 causes of normocytic, Normochromic Anaemia ?
- Renal disease
- Mixed deficiencies
- After acute blood loss
- Anaemia of chronic disease ( some cases )
- Many haemolytic anemias
- Bone marrow failure ( ex. Post chemotherapy, infiltration by carcinoma etc. )
2 types of causes of macrocyctic Anaemia ?
Megaloblastic - vitamin B12 or folate deficiency
Non- megaloblastic - alcohol , liver disease , myelodysplasia (a group of cancers in which immature blood cells in the bone marrow do not mature or become healthy blood cells), aplastic anaemia etc.
What is value of MCV and MCH in mycrocytic, hypochromic anaemia ?
MCV < 80 fL
MCH < 27 pg
What is value of MCV and MCH in normocytic, normochromic anaemia ?
MCV 80-95 fL
MCH > 27 pg
What is value of MCV and MCH in macrocyctic anaemia ?
MCV > 95 fL
What 6 values does iron deficiency decrease
Hb
MCV
MCHC
MCH
Serum iron
Retic count
What value does iron deficiency increase
TIBC ( total iron binding capacity )
Which 2 values does B12 deficiency decrease ?
Hb
MCHC
Which values does B 12 def increase ?
MCV
MCH
Which 5 values does B12 deficiency keep the same
MCHC
MCH
Serum Iron
TIBC
Retic count
Which 5 values does haemolytic anaemia keep the same ?
MCV
MCHC
MCH
Serum Iron
TIBC
Which values does haemolytic anaemia increase ?
Retic count
Which values does haemolytic anaemia decrease ?
Hb
Appearance of blood picture during haemolytic anaemia ?
Normochromic , normocytic ( other than in thalassemia/ haemoglobinopathies )
