Anaemia Flashcards
anaemia
reduction in haemoglobin in the blood
below normal for population
3 causes of low Hb
- reduction production
- increased losses
- increased demand
RBC life span
120 days
haemoglobin is recycled in that time
what are 2 processes of getting anaemia?
- reduced normal red cells
- normal red cells but reduced Hb
how can reduced normal red cells lead to anaemia?
marrow failure
- low RBC count, less Hb present
aplastic anaemia marrow appearance
not making cells
acellular
easy to spot problems
what is the appearance of normal marrow?
cellular
bone trabecular
cells made by stem cells
how can having a normal red cells count but reduced Hb lead to anaemia?
making enough RBC but not enough Hb too go into them
constituents of Hb not made in adequate numbers
- haem production needs folic acid and vitamin B12
- globin chain production arises from abnormal genetic code so wrong proteins
deficiency states - Fe, Folate, Vit B12
abnormal globin chains
- Thalassaemia
- Sickle Cell
chronic inflammatory disease
- rheumatoid arthritis supresses ability to make Hb
- not missing constituents just not forming Hb
haematinics are
things used to make red blood cells
what 3 things are heamatinincs?
- iron
- vitamin B12
- folic acid (folate)
iron sources
- meat
- green leafy vegetables
- iron tablets
what form must iron be in to be absorbed?
2+
haem-based iron can be easily absorbed
what is a haem-based iron (2+) source?
meat based products
what is iron stored in cell as?
ferritin
how is iron transferred from cell to blood?
from storage protein ferritin into blood as haem again
many blood transporters e.g. trasnferrin
what is a stable measure of iron store?
ferritin
ferritin in blood is proportionally accurate to how much is stored in cells
what disease can reduce iron absorption?
achlorhydria
coeliac disease
what is achlorhydria and have can that reduce iron absorption?
Lack of stomach acid
- no conversion of non-haem iron (3+ to 2+)
may be Drug induced (Proton Pump Inhibitors)
- get rid of stomach acid
how can coeliac disease reduce iron absorption?
- Lose villi on endothelial of small intestine
- Flattening of intestinal lining - less SA
how can someone have iron loss? (4)
anything that makes you bleed - internal and external
Gastric erosions and ulcers
- Acid, ulceration expose connective tissue
Inflammatory Bowel disease
- Crohn’s disease
- Ulecerative colitis
Bowel Cancer
- Colonic cancer
- Rectal Cancer
Small amount of bleeding over time
Haemorrhoids
- Notice as not passed through GI so still red
vitamin B12 sources
animal products mainly
also marmite, green leafy veg
cannot be made by humans - need to obtain through diet as made only by bateria
how vitamin B12 absorbed?
Intrinsic factors combine with vitamin B12 to be absorb form GI
- need both
Receptors end of ileum that pick up intrinsic factor
what can be given if vitamin B12 deficient?
injections
not taken via GI tract so can be absorbed readily
what does folic acid do?
combines with iron
needed for DNA synthesis for RBC
if there is a deficiency in iron and vitamin B12 then there is…
problem in absorption
if only iron or vitamin B12 then there is…
problem in diet
vitamin B12 deficiency can be due to (3)
Lack of intake – strict vegans
Lack of intrinsic factor
- Autoimmune stomach disease (Pernicious anaemia)
- Gastric disease
Disease of terminal Ilium
- Crohn’s disease
folic acid sources
green leafy vegetables
folic acid deficiency can be due to (2)
Lack of intake
- Peculiar diet habits
Absorption failure
- Jejunal disease – coeliac disease
- Usually seen co-deficient with iron
what can folic acid deficiency lead to?
Neural Tube defect in foetus
- Cannot be fixed – permanent defect
Fails to close properly
- Spinal column as fails to close
Nerves below not formed correctly – lower limb, bowels etc
why is folic acid important?
Needed for nerve maturation - spina bifida deficiency in pregnancy
how to test for haematinic deficiencies?
blood tests
- ferritin (iron)
- vitamin B12
- folate
can be haematinic deficient before anaemic as Hb as 120 day life span
what is thalassaemia?
normal haem production but genetic mutation of globin chains
- alpha chains (alpha thalassaemia)
- beta chains (beta thalassaemia)
run in populations
what are the possible clinical effects of thalaessmia?
Mild – no effects
- Their normal is having a low Hb – new homeostasis
Chronic anaemia
Marrow hyperplasia (skeletal deformities)
- Bone marrow having to make more globin
- Need more as only some used, change in structure
Splenomegaly
- Spleen removes from blood e.g. wrong RBC due to wrong globin structure
- Spleen gets bigger as higher workload
Cirrhosis
- Too much iron in blood, as over making haem as lack of correct globin
- Haem is no use in excess – storage issue
Gallstones
- Due to more haem for recycling
management of thalassaemia
Best left if not a big issue to patient
Blood transfusions
- Need to give more haemoglobin as not making enough themselves
but Prevent iron overload
- Issue as normal haem so giving excess so too much iron –> cirrhosis and gallstone
what is sickle cell anaemia?
abnormal globin chains, so change in way globin behaves when O2 levels are reduced in RBC
what occurs to RBC in low O2 in sickle cell anaemics?
change in shape
- from flat disc to bent disc shape
cannot fit through capillaries
- blockage
- no blood flow
- serious –> hypoxia and tissue ischaemia
what does someone have if they are heterozygous sickle cell anaemic?
sickle cell trait but not disease
what does someone have if they are homozygous sickle cell anaemic?
sickle cell disease
how can RCC and HCT losses occur for normal red blood cells?
bleeding
usually GI bleeding
- no source of outside bleeding
unexplained anaemia (scope down to find source)
how can RCC and HCT losses occur for abnormal red blood cells?
autoimmune
hereditary - SICKLE, G6PD, spherocytosis
- Cells have reduced life span (<120 days) [Abnormal in RBC shape and duration; May need to make RBC faster to keep level]
- can lead to lower RBC as life span been reduced as removed by the spleen
cases when there is an increase demand of RBC so higher chance if becoming anaemic
- after pregnancy (if blood doesn’t physiologically adapt during to increase volume with fewer but proportional RBC)
- malignant disease (tumours)
3 types of RBC mean cell volumes (MCV)
microcytic
macrocytic
normocytic
microcytic
small RBC
- Fe def , lack of ability to make haem (anaemia and Thalassaemia)
shrunk too far as reduced cellular content
macrocytic
large RBC
- B12/folate def., Retics
RBC start big and decrease in size with maturation between RBC precursor and when they should enter circulation
- not shrunk enough so larger than normal expected size
normocytic
normal RBC
- shrunk to normal expected size
what are reticulocytes?
almost mature RBC (appear bigger as still immature RBC)
why do we have reticulocytes in circulation sometimes?
Released early into the circulation to replace losses
- E.g. after donation, sudden recent blood loss
- Replace loss quickly
Fluid replaced easily
- Bone marrow released immature RBC to try and replace cellular content
what will reticulocytes do to MCV?
increase MCV
- still have cellular parts to them
3 stages to run through in anaemia diagnosis
what is the Hb?
- Normal or not normal
- determine degree of anaemia
what are the RCC and HCT?
- cell deficiency (right number RBC or reduced) or Hb formation deficiency
What is the MCV? - Is there a deficiency picture? - What is the likely deficiency? (Small cells – iron deficiency, Thalassemia Big cells – B12, folic acid deficiency)
3 stereotypical signs of haematinic deficiencies (do not base diagnosis off)
Pale mucosa – more likely if anaemic.
Smooth tongue – iron deficiency
‘beefy’ tongue – vitamin B12 deficiency
anaemia signs
Pale
Tachycardia
- Faster HR as pumping RBC more as same volume of oxygen is carried by fewer RBC
Rarely: enlarged liver and spleen
anaemia symptoms
- Tired & weak
- Dizzy
- Short of breath
- Palpitations (Awareness of increase in HR)
6 investigations for anaemia
HISTORY
FBC (Ferritin & RC Folate/vit B12 )
- All cells and Haematinics
FOB (Faecal Occult Blood)
- Easy – looks for changed haemoglobin
- Small sample of stool mixed with chemical agent to ID altered haemoglobin
- See if any blood in stool – similar for bowel cancer
Endoscopy/Colonoscoopy
Renal Function
- Kidneys make erythropoirtin – needed for RBC production
- normocytic anaemia – correct structure but deficient as not making at all
Bone Marrow examination
what can GI bleeding in young be due to?
- drink
- menstruation
- worry
what can GI bleeding in older people be due to?
bowel disease and cancer
polyp can become malignant
3 methods for anaemia treatment
treat the cause
Replace haematinics
- FeSO4 200mg tds for 3months
- 1mg IM vitamin B12 x 6 then 1mg/2 months
- 5mg Folic acid daily
Transfusions - production failure
- If cannot make haemoglobin correctly (Bone marrow failure)
- Thalassemia
Erythropoietin - production failure
- If suffer from Renal disease
- Erythropoietin injections can boost haemoglobin levels to normal
dental aspects of anaemia
need to correct anaemia before commencing any treatment
General Anaesthesia – O2 capacity
- Send to hospital not in surgery
- Need to go through risk as and benefits - Risk of hypoxia higher
Deficiency States - Fe usually
- mucosal atrophy
- Candidiasis
- ROU – recurrent oral ulceration
- Dysaesthesia
Check Haematinics in mucosal diseases
Sickle cell disease
- check all patients of negroid background before GA
- sickledex test even if no anaemia
general anaesthesia risk for anaemics
greater risk of hypoxia
iron deficiency oral manifestations
- mucosal atrophy
- Candidiasis
- ROU – recurrent oral ulceration
- Dysaesthesia
