M103 T2 L4 Flashcards
What is the % red cells after centrifugation?
~ 45%
What is the number of red cells per litre?
4 x 10^12/L
What are the symptoms of acute anaemia?
Lethargy, Headache
Dyspnea
Palpitations - racing heart or ear ‘whooshing’
Often non-specific symptoms
What are the signs of anaemia? (PTTK)
Pallor (paleness)
Tachypnoea
Tachycardia
Koilonychia - curling of finger nails
What are the five broad causes of anaemia?
Bleeding- chronic or acute Deficiency in necessary components - Iron, B12, folic acid Haemolytic Bone Marrow Dysfunction / Infiltration Poor O2 Utilisation / Carriage
What causes Hemolytic anemia?
increased haemolysis
shortened RBC lifespan due to cell fragility
What is the most common type of anaemia and where?
Iron deficiency anaemia
in the UK and in the world
What are the causes of iron deficiency anaemia?
Bleeding (esp. occult) Diet paired with something else - vegan / vegetarian, malabsorption, nutrient deficiency Increased requirements (Pregnancy but usually supplimented)
What substance in the body is measured to gauge how much iron is in the body and what’s a disadv?
ferritin, but levels can be misleadingly normal
What are the diagnostic tests for iron deficiency anaemia?
Serum Ferritin
Serum Iron
Transferrin
% Transferrin Saturation
What types of bleeding can lead to iron deficiency anaemia?
Menstrual bleeding
Occult GI Malignancy bleeding
GI peptic ulceration bleeding
What three types of categories of RBC size can be used to diagnose anaemia?
Microcytic (small)
Macrocytic (large)
Normocytic (normal)
What is the usual Mean Corpuscular Volume?
Normally about 80-100fL
What deficiencies must be ruled out before diagnosing another type of anaemia other than Macrocytic anaemia?
B12 and folate deficiency
Myelodysplasia
What conditions are related to normocytic anaemia?
Anaemia of chronic disease
Acute haemorrhage
Renal failure
How long do RBCs last in circulation?
100 days
How are reticulocytes counted and how?
flow cytometry, it counts cells with RNA
What can reticulocyte counts indicate the rate of?
the production of RBCs in bone marrow
What cells are present in the blood film of a patient with iron deficiency?
Pencil and Target Cells
What history is taken for when anaemia is suspected?
Dietary, Travel history Ethnicity, family history any GI Symptoms Menstrual history - menorrhagia Bowel history - coeliac / Crohn’s disease
What are symptoms of an issue in the GI?
Dyspepsia / Reflux
Change in bowel habit (melaena)
Weight loss- bowel malignancy
What are the causes of a B12 deficiency?
Dietary - strict vegans, is supplemented with oral B12
malabsorption
can lead to pernicious anaemia
How is pernicious anaemia caused?
parietal cell loss
leads to a deficiency of IF
AAR it cannot absorb B12 in the terminal ileum
How is pernicious anaemia confirmed and treated?
confirmed - check for autoantibodies
treatment - B12 injections (load initially then every 3 months)
What are the causes of a folate deficiency? (DEMAD)
Dietary (most common cause)
Excess utilisation
Malabsorption
Alcohol, Drugs
What are two conditions associated with malabsorption?
Coeliac and Crohn’s disease
What are two conditions associated with the excess utilization of folates?
Chronic haemolysis
Pregnancy
Which drugs could cause a folate deficiency? (PM)
Phenytoin
Methotrexate
What is the most common form of anaemia in hospitalised patients?
anaemia of chronic disease
What are the most common causes of anaemia of chronic disease? (CARC)
Cancer, Auto-immune conditions
Renal failure
Chronic inflammation or infection
What is an example of a chronic infection and an auto-immune condition associated with anaemia of chronic disease?
chronic - TB
auto - rheumatoid arthritis
How does the poor utilisation of iron in the body occur?
Iron is stuck in macrophages of the RES
so it can’t be mobilised into the erythroblasts
What is the dysregulation of iron homeostasis caused by?
Decreased transferrin
Increased hepcidin
Immobilised transferrin
What are the less common causes of anaemia of chronic disease?
poor utilisation of iron in the body
dysregulation of iron homeostasis
Impaired proliferation of erythroid progenitors
How is the proliferation of erythroid progenitors impaired?
due to a blunted response to Epo
an unavailability of iron
Clinically, what is the effect of a low MCV?
iron deficiency or beta thalassemia trait
What is the genetic cause behind sickle cell anaemia?
a point mutation in beta globin gene causing HbS