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Flashcards in Red cell disorders Deck (24)
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1
Q

Anaemia

A

reduced levels of Hb

2
Q

symptoms of anaemia

A

shortness of breath
lethargy
tachycardia
weakness

3
Q

is skin colour a reliable sign for anaemia?

A

no- conjunctiva and nail beds may be pale

4
Q

severe anaemia in elderly can cause

A

angina

5
Q

signs of anaemia

A

glossitis (painful red tongue)
angular cheilitis (fissures at corner of mouth)
DPGs may be elevated in RBCs so O2 more readily given up

6
Q

iron deficiency anaemia

A
microcytic (decreased mean corpsular volume) 
input reduced (diet/ removal of stomach) or output increased (menstruation, GI bleeding ulcers, use of NSAIDs, colon cancer 

demand increased from pregnancy
when bone marrow and macrophage iron stores depleted
monitor full blood count
give iron sulfate

7
Q

Acute iron deficiency anaemia

A

rapid loss of blood- haemorrhage
bp falls
haemodilution

8
Q

chronic iron deficiency anaemia

A

long term bleeding- gastric bleeding, excessive menstruation

9
Q

acute vs chronic anaemia FBC

A
HB: decreases both 
haematocrit decrease both 
MCV: decrease in chronic 
reticulocyte: increase in chronic 
WBC: decrease in acute 
platelets: decrease in acute 
EPO: increase in both 
DBG may be elevated to try to transport more oxygen 
iron stores: normal in acute and zero in chronic
10
Q

Treatment of iron deficient anaemia

A

find and treat underlying cause
oral iron sulfate (take with food as irritates stomach)
prophylaxis in pregnancy: oral iron with folic acid before and after conception- precursor to DNA, reduces chance of neurotube defect, produces RBC
transfusion

11
Q

renal anaemia

A
complicates CRF- impaired kidney doesnt produce EPO 
normocytic anaemia (lack of stimulation to produce RBC) 
treat with iron and EPO
12
Q

pregnancy

A

dilution/ iron deficiency

normocytic- pregnancy increase MCV but iron deficiency decreases it

13
Q

Megaloblastic anaemia

A

rare form of anaemia
abnormal RBC maturation due to defective DNA synth
bone marrow contains megaloblasts (abnormal precursor cells)- nuclear maturation impaired compared to cytoplasm
if macrocytic and not anaemic- alcohol

14
Q

why is megaloblastic anaemia macrocytic?

A

vit B12 or folate deficiency (increased in alcohol abuse)
anaemia, jaundice (XS breakdown of Hb due to ineffective erthryopoiesis)
symptomless, diagnosed on blood test
larger RBC more likley to breakdown

15
Q

what is B12 essential for?

A
cofactor for (THF) purine and pyrimidine synth (cell division) 
requires Castle's intrinsic factor for absorption (absence after gastrectomy) 

• Folate (folic acid) - essential for thymidylate synthesis (a rate limiting step in DNA synth as thymidine is a pyrimidine base), use in pregnancy
Most foods (esp. liver, greens, yeast, marmite)
• Methotrexate - inhibits dihydrofolate reductase (therefore folate regeneration impaired - treat with folinic acid), immunosuppressant, impairs DNA synth
• Pernicious anaemia - lack of intrinsic factor for absorption of B12 due to autoimmune disease - treat with hydroxocobalamin i.m. (bypass absorption)
• Crohn’s Disease- malabsorption of B12, folate or iron

16
Q

haemolytic anaemia

A

increased rate of RBC destruction
• Spherocytosis - genetic - abnormal reduction in RBC membrane protein (spectrin) - cells fragile
• Acquired - haemolytic transfusion reaction, malaria, drug-induced
• causes Jaundice (?) and enlarged spleen (red cell destruction) - folate deficiency may occur due to increased erythropoiesis

17
Q

sickle cell anaemia

A

Genetic SNP: single nucleotide polymorphism
valine substituted for glutamic acid
abnormal Hb- crystals at low o2 can block microcirculation- muscle pain- can cause haemolytic anaemia

18
Q

Thalassaemia

A

Genetic- deletion of genes
Reduced rate of alpha or beta globin units production many variations e.g. deletion of both alpha-genes leads to death in uterus as Hb (gamma4) produced
one alpha deletion- reduced haematocrit and RBC volume

19
Q

Aplastic anaemia

A

insufficient production of RBC, platelets (pancytopenia) and WBC (can just be RBC pure red cell aplasia)

decreased resistance to infections, increased bleeding and tiredness

20
Q

how is aplastic anaemia acquired?

A
viral, radiation and drugs 
Cytotoxic (anticancer) agents
		Chloramphenicol- antibiotic
		Sulphonamides- antimycrobial
		Insecticides
21
Q

treatment of aplastic anaemia

A
  • Immunosuppressants – prevent immune destruction of stem cells
  • Colony-stimulating factors - increase WBC count
  • Bone marrow transplant - with tissue match
22
Q

polycythaemia

A

Increased Hb content and haematocrit (>55 in males and >47 in females)
increased blood viscosity- poor tissue perfusion

23
Q

signs and symptoms of polycythaemia

A
Ruddy appearance
Headaches
Blurred vision
Hypertension
Cyanosis- sluggish blood flow- deoxygenation
24
Q

causes of polycythaemia

treatment

A

primary: changes in bone marrow, stem cell defect
secondary: increased EPO- altitude, smoking, renal carcinoma and COPD

treatment of primary: venesection (bleeding), radioactive phosphorous (reduce turnover stem cells), cytotoxic agents- myelosupression (target RBC)