anaemia Flashcards
what is it?
• Reduced total red cell mass – not easy to measure in routine practice so haemoglobin concentration is a surrogate marker, as is haematocrit
what are the principles of haemoglobin measurement?
Reduction in haemoglobin concentration below that which is optimum for that individual
or
Reduction in haemoglobin concentration below 95% range for the population
what are the 2 types of pathophysiology to cause anaemia
decreased production (low reticulocyte)
- hypoproliferative - reduced amount of erythropoiesis
- Maturation abnormality – erythropoiesis is present but ineffective (Cytoplasmic defects: impaired haemoglobinisation and Nuclear defects: impaired cell division)
Increased loss or destruction of red cells (high reticulocyte count)
o Bleeding
o Haemolysis
assuming state anaemia values are…
o Adult males
Hb <130g/L Hct <0.38
o Adult females
Hb <120g/L Hct <0.37
how is haemoglobin concentration measured
using a spectrophotometric method because Hb is red
what is haemocrit
% or ratio of red cells calculated by adding up the calculated volume of the red cells it counts
what are the measured red cell indices
o Haemoglobin conc
o Number of red cells (concentration)
o Size of the red cells (mean cell volume or MCV)
what are the calculated red cell indices
o Haematocrit
o Mean cell haemoglobin
o Mean cell haemoglobin concentration
what are the other investigations that can be done into red blood cells
o Blood film – look at cellular morphology
o Reticulocyte count – assess marrow response
o Additional tests – depending on clinical details and lab findings
maturation abnormality anaemias
Mean cell volume – useful tool in distinguishing cytoplasmic and nuclear defects
o If MCV low (microcytic) consider problems with haemoglobinisation
o If MCV high (macrocytic) consider problems with maturation
Hypochromic, microcytic anaemias – deficient haemoglobin synthesis, a cytoplasmic defect
