Flashcards in Approach to Anaemia Deck (53)
What are the 2 potential definitions of anaemia?
1. Reduction in haemoglobin concentration below that which is optimum for that individual.
2. Reduction in haemoglobin concentration below 95% range for the population.
'Reduction in haemoglobin concentration below that which is optimum for that individual' is a diagnosis of anaemia. Why is this difficult to clarify?
Because we often don't know what someones normal Hb is
Hb of <120 in a female makes anaemia likely
Hb <110 in a female, who is pregnant, makes anaemia likely
Children from 6 months to 6 years can be diagnosed with anaemia if Hb ...
Children from 6 to 14 can be diagnosed with anaemia if Hb ...
What are the main tools of diagnosing anaemia?
History + exam
After history + exam, what other investigations can be done to diagnose anaemia?
* full blood count indices
* reticulocyte count
* blood film features
* haematinics (ferritin/B12/folate)
* bone marrow
* Specialised tests (hb electrophoresis etc)
What are the 2 main groups of anaemia?
1. Decreased production.
2. Increased loss or destruction of red cells.
What are the 2 causes of a decreased production of RBC's?
1. Hypoproliferative – reduced AMOUNT of erythroipoiesis
2. Maturation abnormality – erythropoiesis present but ineffective
What 2 things can be classified as a maturation abnormality, resulting in decreased production of RBC's?
1. Cytoplasmic defects - impaired haemoglobinisation
2. Nuclear defects - impaired cell division
What are the 2 main causes of increased loss/destruction of RBC's?
What is reticulocyte count a marker of?
Red cell production
What does it mean if reticulocytosis is seen?
That red cell production is increased
If someone has anaemia + a reticulocytosis (increased red cells), what does this mean?
How can bleeding and haemolysis be differentiated?
* If bleeding: red cells are gone.
* If haemolysing: increased products of red cell destruction are seen.
In haemolysis, what are the products of red cell destruction which are seen?
* Increased unconjugated serum bilirubin.
* Increased urinary urobilinogen.
In reticulocytosis, what happens to MACROPHAGE-RICH tissues?
What does haemolysis result in?
Anaemia + jaundice, sometimes with splenomegaly.
Haem is broken down to porphyrin and Fe3+. The porphyrin is broken down to form bilirubin, what is this then made into?
Unconjugated, albumin bound bilirubin in the plasma
What is unconjugated, albumin bound bilirubin broken down to form?
Conjugated bilirubin in liver hepatocytes
If you suspect haemolytic anaemia, what should you look for evidence of?
Red cell breakdown products and a reticulocytosis
In an anaemic patient, reticulocyte count should be appropriately increased if what?
The bone marrow is functioning normally in response to erythropoietin to restore homeostasis.
By how much can normal marrow increase red cell production by?
What is anaemia with a lesser reticulocyte response at least partly due to?
Impaired red cell production
What can MCV be classified as?
What can film/MCH (mean corpuscular haemoglobin) be classified as?
What is the commonest cause of hypochromic microcytic anaemia?
Iron deficiency anaemia is not a diagnosis so you must always investigate for a cause