Anaemia Flashcards
Blood donations tested for?
- ABO group and RhD type
Infection:
Microcytic anaemia causes
- Iron deficiency
- Thalassaemia
- Anaemia of chronic disorder
Normocytic anaemia causes?
- Acute blood loss
- Haemolysis
- Anaemia of chronic disorder
- Bone marrow infiltration
- Combined haematinic deficiency
Macrocytic anaemia causes
- B12/folate deficiency
- Haemolysis
- Hypothyroidism
- Liver disease
- Alcohol excess
- Myelodysplasia
Effect of the following on the RBC
- age,
- gender,
- altitude,
- smoking behaviour
- stage of pregnancy
- ageing –> suppressed bone marrow
- male post puberty higher than female
- Hb rises with altitude
- increased Hb
- increased RBC, but more plasma so looks diluted,
Iron Deficiency Anaemia clinical features
- Angular stomatitis
- Glossitis
- Koilonychia
Iron Deficiency Anaemia causes?
- Dietary (80% from meat, 20% from vegetables)
- Physiological (infancy, adolescence, pregnancy)
- Blood loss
- Malabsorption e.g. coeliac disease
where is iron absorbed?
duodenum
Anaemia of chronic disease causes?
- Chronic infection/inflammation
- Malignancy
- Uraemia
- Endocrine disorders
Megablastic RBC features?
- RBC precursors are abnormally large because of impaired DNA synthesis
- cell grows, but doesnt divide
Causes of megablastic RBC?
- Vit B12 deficiency
- folic acid deficiency
Where vit b12 stored?
liver
where vit b12 synthesised
by micro-organisms: only
present naturally in animal produce
how vit b12 gets absorbed?
- combines with intrinsic factor secreted by gastric parietal cells and
absorbed in terminal ileum.
Cause of vit b12 deficiency?
- Dietary: veganism, rare
- Intrinsic factor deficiency: Pernicious anaemia
- Intestinal malabsorption:
- Disease of terminal ileum e.g. Crohns
- Blind loops & small bowel diverticulae
Clinical features of vit b12 deficiency ?
- Anaemia
- Jaundice
- Glossitis
- Neurological deficit (don’t get this with folic acid deficiency)
Management of vit b12 anaemia?
I. Vitamin B12 replacement as IM injection most common – 3x per week for 2 weeks then maintenance phase.
II. Oral folic acid replacement.
Why replace vit b12 before folic acid?
- risk subacute combined degeneration of the cord (with permanent neurological
sequelae) if folic acid replaced in absence of vitamin B12.
Replace B before F!
Source of folic acid?
Dietary sources:
- green vegetables,
- liver,
- nuts,
- cereals.
Folic acid absorbed in?
jejenum
Causes of folic acid deficiency?
- Dietary common in elderly, poor diet related to alcohol misuse.
- Increased utilisation e.g. in pregnancy,
- Malabsorption e.g. coeliac disease.
- Drugs e.g. anticonvulsants.
- Excessive loss e.g. renal dialysis
Normal RBC life span?
120 days
2 types of thalassaemia
- Alpha Thalassaemia
- Beta Thalassaemia
3 types of beta thalasaemia?
- Beta Thalassemia trait (carrier) : Asymptomatic, normal life span
- Beta Thalassemia intermedia
- Variable phenotype and life span - Beta Thalassemia major
- Early death if untreated
Β thalassaemia major def?
Complete absence of HbA
Consequence of Β thalassaemia major
- Excess α chains accumulate and damage RBC
- Ineffective erythropoiesis
- Excessive RBCs Destruction
Long term B thalasaemia major consequence?
- Iron Overload
- Extra-medullary hematopoiesis
Sx of Beta thalassaemia major?
- Symptomatic anaemia in first few months of life.
- Jaundice
- Growth retardation
- Bony abnormalities especially of the facial bones.
- Enlarged
spleen and liver
Treatment of β Thalassaemia major
- Regular blood transfusions (Life long)
- Iron chelation e.g. Desferrioxamine, Deferiprone, Deferasirox
- Folic acid
- Bone marrow transplantation in early life
Alpha Thalasaemia def
- deficient/absent alpha subunits
- Excess beta subunits
- Excess gamma subunits newborns
Alpha Thalasaemia types?
- Trait: 2 genes not working
- Hemoglobin H Disease: 3 genes not working
- Major (Hemoglobin Bart’s): ALL 4 not working
Hemoglobin H (HbH) disease thalasasemia clinical features
- jaundice,
- hepatosplenomegaly,
- leg ulcers,
- gallstones
Hemoglobin H (HbH) disease thalasasemia management
folic acid,
transfusions,
splenectomy
Hb Barts hydrops
- no alpha chains produced, Mainly gammma chains
- Intrauterine death and stillborn
Life span of sickle cell?
Lives for 20 days or
less
3 complications of sickle-cell anaemia
- haemolysis
- vaso-occlusion
- hyposplenism
HbSS (sickle cell anaemia) increases the chance of getting which conditions?
Acute chest syndrome,
PE,
infection
What are HbSS different complications in various age?
- Ischaemic: more common in children and older adults, and lowest in
adults aged 20 to 29 years - Haemorrhagic: most frequent in the 20- to 29-year age group
Emergency mx of HbSS?
reduction of HbS% by transfusion
Sickle cell trait (HbAS)
- Usually asymptomatic
- Inability to concentrate urine (Occasionally renal papilliary necrosis)
Sickle cell solubility test
- The sickle cell solubility test relies on the relative insolubility of HbS in concentrated phosphate buffers compared to Hb A
and other Hb variants. - Hb S precipitates causing a cloudy solution
