Red cell disorders Flashcards
What is the definition of anaemia
Reduced level of Hb (haemoglobin)
Symptoms of anaemia
- Shortness of breath
- Weakness/lethargy
- Tachycardia (high resting heart rate)
- Glossitis (painful red tongue) and angular cheilitis (fissures at corner of mouth)
What is not a reliable sign of anaemia vs what is
Skin colour is not reliable
-Instead check nail bed and conjunctiva (they may be pale)
What may severe anaemia in elderly patients cause
Angina
What may be more elevated in RBCs in those with anaemia
DPG so O2 is more readily given up to tissues
What is iron deficiency anaemia
Microcytic (decreased MCV) which means that the mean corpuscular volume is reduced of red blood cells
In what ways can you decrease input to cause iron deficiency anaemia
Poor diet
Surgical removal of stomach
In what ways can you increase output to cause iron deficiency anaemia
Menstruation
Gastrointestinal bleeding ulcers which may be caused by the use of NSAIDs (eg ibuprofen)
IN what ways can you increase demand to increase iron deficiency anaemia
Pregnancy
What is the main cause of iron deficiency
Increased output (eg menstruation)
Difference between acute vs chronic bleeding
Acute- Over time, there is haemodilution by the addition of water
chronic- long term bleeding ie menstruation and there is no haemodilution
How to treat iron deficiency anaemia (not in pregnancy)
Find the underlying cause (eg menstruation or GI tract bleeding)
- Give oral iron (FeSO4)
- sometimes a transfusion
How to treat iron deficiency anaemia in pregnant women
Prophylaxis (oral iron) with folic acid
What is normocytic anaemia
Normal sized red blood cells, but a low number of red blood cells
What leads to normocytic anaemia
Renal anaemia
How do you treat renal anaemia
Fe and EPO
What type of anaemia could there be in pregnancy
Iron deficiency
Normocytic
Why could there be normocytic anaemia in pregnancy
Pregnancy increases MCV but iron deficiency decreases MCV so they could cancel out. This means the anaemia may be normocytic instead
What is megaloblastic anaemia
Macrocytic anaemia (abnormally large red blood cells called megaloblasts found in bone marrow)
Why is there abnormal red blood cell maturation (causes megaloblastic anaemia)
Due to defective DNA synthesis (due to vitamin b12 or folate deficiency)
What is B12 used as
A cofactor for purine and pyrimidine synthesis (therefore cell division)
What does B12 require for absorption
Intrinsic factor
What can a microcytic but not anaemic patient mean
Evidence of alcohol abuse
What can megaloblastic anaemia lead to
Haemolytic anaemia
In DNA synthesis, what is folic acid used as
A building block
What in DNA synthesis is used as a drug target
DHF reductase which is involved in DNA synthesis
What drug inhibits DHF
Methotrexate (so used to prevent DNA synthesis and so is used as an anti-cancer drug)
What complication does methotrexate cause and how to solve this
Stops Folate regeneration so this is treated with folonic acid
What do haemolytic anaemias do
Increased rate of RBC destruction
Two different types of haemolytic anaemias
Spherocytosis- genetic
Acquired
What is spherocytosis
Abnormal reduction in RBC membrane protein and so cells become fragile
Why might there be a folate deficiency and what are the symptoms of this
Due to increased erythropoiesis (blood cell formation)
-Jaundice and enlarged spleen (because that’s the site of red cell destruction)
What does sickle cell anaemia cause
Haemolytic anaemia
What causes thalassaemias and what Is it
Genetics
People with thalassaemia produce either no or too little haemoglobin
What is aplastic anaemia
Insufficient production of RBCs, WBCs and platelets (pancytopenia)
What causes aplastic anaemia
- Viral, radiation or drugs
- Cytotoxic agents (anticancer)
- Chloramphenicol
- INsecticides
How is aplastic anaemia treated
- Bone marrow transplant
- Immunosuppressants to prevent destruction of stem cells
- COlony-stimulating factors which increase white blood cell count
What is polycythaemia
Increased haemoglobin content and haematocrit
Symptoms of polycythaemia
- HEadaches
- Blurred vision
- HYpertension
- Cyanosis (blue skin) caused by sluggish blood flow
What is polycythaemia caused by (primary and secondary)
primary- changes in bone marrow, stem cell defect
secondary- increased erythropoietin (stimulates stem cells to turn into red blood cells) which is increased due to altitude, smoking and renal carcinomas
Treatment of primary polycythaemia
- Bleeding the patient
- Radioactive phosphorus (myelosuppression which is suppression of bone marrow)
