Anaemia Flashcards
How does a reduction in plasma volume effect Hb levels + when is this situation seen
Increases them
Dehydration
What are the three types of anaemias
- Hypochromic (low MCV)
- Normochromic (normal MCV)
- Microcytic (high MCV)
Why may some patients be asymptomatic for anaemia
- Slowly falling level of Hb = compensation as oxygen-dissociation curve will shift to the right, so that oxygen is more easily dissociated from Hb
Symptoms of anaemia
- Fatigue, headaches, faintness
- Breathlessness
- Angina
- Intermittent claudication
- Palpitations
How does anaemia additionally effect older people
Exacerbates cardiorespiratory problems
Clinical signs of anaemia
- Pallor
- tachycardia
- Systolic flow murmur
- Cardiac failure
SPECFIC:
- Koilonychia (spoon-shaped nails in longstanding iron deficiency anaemia)
- jaundice (haemolytic anaemia)
- Leg ulcers (associated with sickle cell)
- Bone deformities (thalassaemia)
Investigations for anaemia in peripheral blood
1, Red cell indices
- the WCC
- Platelet count
- Reticulocyte count (indictes marrow activity)
- Blood film
What should be seen on a blood film for anaemia
Two populations of red cells are seen - dimorphic
How is bone marrow investigated in anaemia
- Cellularity of marrow
- Type of erythropoiesis
- Infiltration of marrow
- Iron Stores
RBC lifespan
120 days
How does reticulocyte count correlate with bone marrow production measurement
Low count - Production of Bone marrow is an issue
High count - removal of bone marrow is an issue
What is MCV
Average volume of RBCs
What is the main cause of anaemia
Iron deficiency
Anaemia caused by chronic disease
Thalassaemia
What is the average intake of iron
15-20mg
How much of ingested iron is absorbed by the duodenum
10%
How is Iron absorbed
- AT into duodenal epithelial cells via HCP1 and incorporated into Ferritin
What happens to absorbed iron so it can travel in th blood
Bound to transferrin -> bone marrow to be incorporated into new erythrocytes
Where is iron stored in th body
Reticuloendothelial cells as FERRITIN or HAEMOSIDERIN (macrophages in bone marrow, liver and spleen)
Causes of iron deficiency anaemia
- Menorrhagia
- GI bleeding
- Hookworm (leading cause - GI blood loss)
Poor diet
Malabsorption
What happens to RBCs in iron-deficiency anaemia
- Crucial for haemoglobin production + reduction in iron = decrease in haemoglobin + smaller RBCs
MICROCYTIC ANAEMIA
Clinical presentation of iron-deficiency anaemia
- Brittle nails + hairs
- Koilonychia
- Atrophy of the tongue papilla
- Cheilosis (ulceration of mouth corners)
What are three differential diagnostics for iron-deficiency anaemia
- Thalassaemia
- Sideroblastic anaemia
- Anaemia of chronic disease
How is iron-deficiency anaemia diagnosed in blood tests
- RBCs and microcytic and HYPOCHROMIC (pale)
- Poikilocytosis (variation in shape) and anisocytosis (variation in size)
- Serum iron is low
- TIBC (total iron-binding capacity) rises to normal (transferrin below 19% saturation = iron deficiency)
5
How does serum ferritin help in diagnosis
Level reflects amount of iron stored - confirms DIAGONSIS
What happens to the number of transferrin receptors in iron-defiiceny anaemia
Increases
Reticulocyte in iron deficiency anaemia
Low
How is Iron deficiency anaemia treated
- Oral Iron (FERROUS SULPHATE)
Side effect of ferrous sulphate
Nausea
Abdominal Discomfort
Diarrhoea/constipation
Black stools
What can be given as a replacement to serous sulphate if side effects are bad
Ferrous GLUCONATE
In extreme cases (e.g. severe iron malabsorption) what can be given
Parenteral iron
What is anaemia of chronic disease
Anaemia that is secondary to chronic disease = anaemia
RBC appearance in chronic disease anaemia
NORMOCYTIC (could be microcytic)
When can RBCs be microcytic in CDA
Rheumatoid and crohn’s disease
What is the most common anaemia in hospital patients
CDA
What chronic infections cause anaemia
- TB
- Crohn’s
- Rheumatoid
- SLE
- Malignancy
Pathophysiology of CDA
- Decreased release of iron from bone marrow to developing erythroblasts (before they become reticulocytes)
- Inadequate erythropoietin response (cytokine which increases RBC production) to anaemia
- Decreased RBC survival
Clinical presentation of CDA
- Fatigue
- Headache
- Dyspnoea
- Angina
- Anorexia
- Intermittent Claudication
- Palpitations
Level of iron and TIBC in CDA
- LOW TIBC and SERUM IRON
Level of serum ferritin in CDA
Normal/ raised due to inflammatory process
Level of transferrin receptors in CDA
Normal
Appearance of RBCs in blood count
- NORMOCYTIC
- MICROCYTIC
- HYPOCHROMIC
How is CDA treated
Erythropoietin is effective in raising Hb levels
Side effect of treating with erythropoietin in CDA
Flu
Hypertension
Rise in platelet count
thromboembolism
Main causes of normocytic anaemia
- ACUTE blood loss
- CDA
- Endocrine disorders
- Renal failure
- Pregnancy
Clinical presentation of normocytic anaemia
- Fatigue, headaches, faintness
- Dyspnoea
- Angina
- Anorexia
- Intermittend claudication
- Palpitations
B12 and folate levels in normocytic anaemia
Normal
Reticulocyte level in normocytic anaemia
Raised
Hb level in normocytic anaemia
Low
Appearance of RBCs in blood count
NORMOCYTIC
How is normocytic anaemia treated
- Improve diet with vitamins
2. Erythropoietin injections
What can macrocytic anaemia be divided into
Megaloblastic
Non-megaloblastic
What is megaloblastic macrocytic anaemia
Presence of erythroblasts with delayed nuclear maturation because of delayed DNA synthesis - large megaloblastic cells with no nuclei
What is non-megaloblastic macrocytic anaemia
Erythroblasts are normal
Main causes of megaloblastic macrocytic anaemia
- B12 deficiency
2. Folate deificnecy
What is B12 also known as
Cobalamin
Non-megaloblastic causes of macrocytic anaemia
- Alcohol
- Liver disease
- Hypothyroidism
- Haemolysis
- Marrow failure
- Marrow infiltration
- Myeloma
What kind of anaemia is pernicious anaemia
Megaloblastic
Where is B12 found
Meat
Fish
Dairy
Is B12 found in plants
No
How long are body stores of B12
4 years
How is B12 absorbed
Binding to intrinsic factor produced by parietal cells
Where is B12 absorbed
Terminal ileum
What is B12 needed for
Thymidine and DNA synthesis
Pathophysiology of pernicious anaemia
Impairment of DNA synthesis = delayed nuclear maturation
Large RBCs + decreased RBC production in marrow
Why is bone marrow most effected in pernicious anaemia
As its most active in terms of cell division
Why is pernicious anaemia autoimmune
- Parietal cells are attacked = atrophic gastritis + loss of intrinsic factor production + B12 malabsorption
What age group does Pernicious anaemia effect
Elderly
Risk factors for pernicious anaemia
- Female
- Elderly
- Fair-heard, blue eyes
- Blood group A
- Addison’s disease + thyroid
Specific diagnosis for pernicious anaemia
Intrinsic factor antibodies in blood tests
In what proportion of patients can intrinsic factor be found in
50% of patients
Signs of pernicious anaemia
- Parietal and chief cells replaced by mucin-decreting cells
- Autoimmune gastritis affecting funds with plasma cell + lymphoid infiltration
- Achlorhydria (reduced HCL production) + absent of intrinsic factor secretion
- Parietal cell antibodies in serum
Clinical presentation of pernicious anaemia
- Normal symptoms for anaemia
- Lemon-yellow skin colour
Red sore tongue + cheilosis
Why is skin yellow in pernicious anaemia
Caused by ex ess breakdown of haemoglobin (body will try to remove large RBCs that are defective)
Neurological features of pernicious anaemia
- Symmetrical parasthesia in fingers and toes
- Weakness + ataxia
- Paraplegia
- Dementia / hallucinations and optic atrophy from B12 deficiency
When do neurological symptoms show in pernicious anaemia
Low levels of B12
Appearance of RBCs in blood count of pernicious anaemia
MACROCYTIC
Appearance of microcytes in pernicious anaemia
- Oval + hyperhsegmented neutrophil polymorphs with 6 or more lobes in nucleus
Serum bilirubin levels in pernicious anaemia
Raised
Why would bilirubin levels in the plasma be raised in pernicious anaemia
As a result of ineffective erythropoiesis + increased RBC breakdown
What happens to Hb count in pernicious anaemia
Low
Reticulocyte count in pernicious anaemia
Low
What is the diagnostic factor for pernicious anaemia
Low intrinsic factor count
How is pernicious anaemia treated
Oral B12 - dietary causes
OR IM HYDROXOCOBALAMIN
Role of Hydroxocobalamin
Replenishes B12 stores
Where is folate found
Green veg
Body stores for folate
4 months
Where is folate absorbed
Duodenum
Pathophysiology caused by folate deficiency
Impairs DNA synthesis = delayed nuclear maturation
Large RBCs and decreased RBC production in marrow
Why is folate essential in fetal development
Can result in neural tube defects if deficient
Risk factors for folate dificeny anaemia
Elderly
Pregnant
Alcohol
Crohn’s or coeliac
Clinical presentation for folate deficiency anaemia
Same as pernicious EXCEPT no NEUROPATHY
How is folate deficiency anaemia diagnosed
Same as pernicious except B12 levels should be the same, folate levels should be LOW
How is folate deficiency treated
Folic acid tablets daily for four months - never without B12
Why can’t folate be given without B12
Cause degeneration of spinal cord
What is haemolytic anaemia
Premature breakdown of RBCs, before hitting 120 day lifespan
What happens to haemoglobin in renal tubular cells in haemolytic anaemia
Broken down and deposited in cells as HAemosiderin
Why does shortening red cell survival not equal anaemia all the time
Cause compensated increase in RBC production by bone marrow
What is compensated haemolytic disease
Red cell loss is contained within marrow’s capacity for increased output
How does bone-marrow compensate in haemolytic anaemia
Increases output by 6-8 times by increasing proportion of cells committed to erythropoiesis (erythroid hyperplasia) + expanding volume of active marrow
Reticulocytes are released PREMATURELY
Characteristics of RBCs in haemolytic anaemia
MACROCYTIC + stain with a light blue tinge on peripheral blood film
Main causes of haemolytic anaemia
- Hereditary spherocytosis
G6PD deficiency
B Thalassaemia
A Thalassaemia
Sick cell disease
Autoimmune haemolytic anaemia
Features of haemolytic anaemia
- High serum unconjugated bilirubin
- High urobilinogen
- High fecal stercobilinogen
- Splenomegaly
- Bone Marrow expansion
- Reticulocytosis (more reticulocytes)