Review of Anaemia Flashcards
What is the definition of anaemia
Number of red cells or their oxygen-carrying capacity: insufficient to meet physiological needs
What is the most common disorder globally
anaemia
How many people does anaemia effect
- it effects 1.6 billion people
where are red blood cells produced
RBCs produced in the bone marrow (BM) from myeloid progenitor cells
What do red blood cells need to be produced
- permissive BM micro-environment
- adequate substrate :
- iron
- vitamin B12
- folate
What is erythropoiesis
Production of red blood cells
What controls erythropoiesis
= Erythropoietin
Where is EPO synthesised
= Synthesis at peritubular fibroblasts in the renal cortex
What is the aim of EPO
reduction of oxygen tension
How do you classify anaemia
based on red cell size and morphology
- Microcytic - under 80fl
- macrocytic - over 96
- normochromic - 80-96fl
or
Decreased BM production/output
- BM aplasia/infiltrate
- ineffective haematopoiesis such as HIV, MDS
- substrate deficiency e.g. iron or folate deficiency
- EPO insufficiency
or
underlying mechanism - peripheral loss/destruction
- bleeding
- sequestration
- haemolysis
What is the differenced in how anaemia is investigated by pulmonologists and cardiologists
- Pulmonologists and Cardiologists - hypoxia on anatomical level
- Haematologists – hypoxia at molecular and cellular levels
what are the general symptoms of anaemia
- increased tiredness/fatigue
- dyspnoea
- decreased effort tolerance
What does the severity of symptoms of anaemia depend on
- degree of anaemia
2. rate of haemoglobin decrease
What should you include in a history with anaemia
- information about the presenting complaint and duration of the problem
- transfusion history
- dietary history including pica(craving for unusual food items, generally associated with iron deficiency)
- travel history (to endemic malarial or other infectious areas)
- change in bowel habits
- bleeding (such as GI and genito-urinary)
- drug history (e.g. anticoagulants, antiplatelet agents, Reno toxic agents)
- chronic disease (e.g. HIV and TB)
- Surgery (e.g. gastrectomy, small-bowel surgery, bariatric surgery)
- current or recent pregnancy
- family history
What are the clinical signs in a clinical examination of anaemia
Skin and mucous membrane
- Pallor is the cardinal clinical sign
- angular stomatitis - caused by iron deficiency
- glossitis in nutritional deficiency - B12 deficiency
- Kolionychia (spoon-shaped nails) - caused by iron deficiency
- premature greying
- scleral icterus
What causes angular stomatitis and koilonychia
iron deficiency
What deficiency causes glossitis
B12 deficiency
what would you find of a neuromuscular clinical examination on someone with anaemia
- Muscle weakness
- Headache, lack of concentration, drowsiness
- Tinnitus
- Paraesthesias, peripheral neuropathy, ataxia and loss of vibration sense
Name some cardiovascular examination findings that you would find on someone with anaemia
- Hyperdynamic circulation with ‘flow’ murmurs
2. Cardiac failure
Name the clues for infection and malignancy that you can find on someone who is anaemic
- Hepatosplenomegaly
- Lymphadenopathy
- Bleeding manifestations (petechiae, purpura, ecchymosis)
what laboratory tests do you carry out
- FBC
- Reticulocyte counts
- microscopic blood smear
What is the normal range of haemoglobin for males, females and pregnancy
• Male Hb: 13.8 - 17.9 g/dL (anaemia <13 g/dL)
• Female Hb: 12.4 - 15.5 g/dL (anaemia <12
g/dL;
• Pregnancy <11 g/dL).
What is hematocrit
- the volume percentage of red blood cells in blood
What is the percentage of hematocrit in adult males and women
- Adult males: 42%-54%
* Adult women: 38%-46%
What is MCV
- Mean corpuscular volume or mean cell volume = this is the average volume of a red blood cell
How do you work out the MCV
the hematocrit (Hct) is divided by the concentration of RBCs
What is the MCH
mean corpuscular haemoglobin
- this is the average mass of haemoglobin per red blood cell
How do you work out the MCH
- calculated by dividing the total mass of haemoglobin by the number of red blood cells in a volume of blood
What can cause microcytic anaemia
- iron deficiency anaemia
- lead poisoning
- anaemia of chronic inflammation
- sideroblastic anaemia
What can cause normocytic anaemia
- haemolytic anaemias
- bone marrow disorders
- hypersplenism
- acute blood loss
- anaemias of chronic disease
What can cause macrocytic anaemia
- Vitamin B12 deficiency
- folic acid deficiency
- Liver disease
- hypothyroidism
- reticulocytosis
What should you do if bone marrow pathology is suspected
- Bone marrow aspirate: morphological assessment in cellular detail but the architecture is disrupted
- trephine biopsy sections - the architecture is preserved - detect pathology such as granulomata and fibrosis
When should you use a trephine biopsy
- the architecture is preserved - detect pathology such as granulomata and fibrosis
What is the difference between a trephine biopsy and a bone marrow aspirate
Bone marrow aspirate
- assessment in cellular detail
- architecture is disrupted
trephine biopsy
- architecture is preserved
