Lecture 2 - Overview of Anaemias Flashcards
What is anaemia?
Reduced haemoglobin level in relation to age, sex, and physiological state
NZ adult reference ranges: 115–155 g/L (female), 130–175 g/L (male)
What are the severity classifications of anaemia based on haemoglobin levels?
- Mild: > ~100 g/L
- Moderate: 70 - 100 g/L
- Severe: < 70 g/L
What are common clinical features of mild anaemia?
- Often none
- Weakness
- Fatigue
- Shortness of breath
- Heart racing or palpitations
- Feeling cold
What signs might indicate severe anaemia during clinical examination?
- Pallor (paleness) of mucous membranes
- Increased pulse rate
- Myocardial ischaemia in ECG/exercise test
What are the classifications of anaemia based on blood count?
- Normal
- Anaemia
- Polycythaemia
What are the types of cells in anaemia classification?
- Microcytic
- Normocytic
- Macrocytic
What are the aetiological causes of anaemia?
- Increased loss or destruction
- Impaired red cell production
What is the reticulocyte count?
Count of young red cells (1-2 days old) in the blood, indicating marrow production
What causes microcytic anaemias?
- Iron deficiency
- Thalassaemias
- Anaemias of inflammation
What is the most common cause of anaemia?
Iron deficiency
What is the best test for iron stores?
Ferritin
What characterizes thalassaemias?
Reduced production of either α or β globin chain of haemoglobin
What is anaemia of inflammation?
A type of anaemia caused by reduced iron availability and sequestering of iron stores
What is the role of hepcidin in anaemia of inflammation?
Hepcidin reduces release of iron from stores and blocks intestinal absorption
What are some causes of anaemia of inflammation?
- Rheumatoid arthritis
- Inflammatory bowel disease
- Severe chronic infections
True or False: Anaemia of inflammation responds to iron therapy.
False
What does C-reactive protein indicate?
A protein produced in response to inflammation; used as a diagnostic test
What happens to serum iron during inflammation?
Serum iron levels decrease, reducing availability to erythroblasts
Fill in the blank: Anaemia is classified by _______ and aetiology.
morphology
What is the relationship between iron deficiency anaemia and red blood cell characteristics?
Small, pale red cells with low MCV and low MCH
What are some features of anaemia of inflammation?
- Neutrophil and platelet counts may be elevated
- C-reactive protein raised
What are the common symptoms of severe anaemia?
- Angina
- Claudication
- Confusion from inadequate oxygen delivery
What is the role of centration in the immune system?
Part of the natural immune mechanisms
What is a common diagnostic test used to detect inflammation?
Centration
What level of centration is observed in acute severe bacterial infections?
Very high level
How does centration change in viral infections?
Only a mild increase
In which conditions is centration elevated?
- Arthritis
- Crohn disease
- Some cancers
- Acute tissue injury
What is the implication of the phrase ‘Evidence based medicine?’
Be a skeptic
Who conducted research on students’ interaction and ability to recall lecture content?
Bligh DA, 2000
What did Jack Adams find regarding attention to manual skills after a brief rest?
Marked improvement
What is the significance of a rest period in teaching methods?
Strong case for short breaks and changes in teaching method
What deficiency is associated with macrocytic anaemias?
- Folic acid
- Vitamin B12
What does ‘megaloblastic anaemia’ describe?
Appearance of erythroblasts in the marrow
What is a rare cause of folate deficiency?
Fortification
What is the most common cause of vitamin B12 deficiency?
Autoimmune destruction of stomach cells
What are some non-megaloblastic causes of macrocytic anaemias?
- Liver disease/alcohol
- Haemolytic anaemias
- Increased red cell production
What happens to reticulocytes in response to blood loss?
Increased production
What is the typical reticulocyte size compared to mature red cells?
20-30% larger
What is the normal reticulocyte count range?
20-100x10^9/L (1-2%)
What can lead to macrocytosis?
Very high reticulocyte count
What are common causes of normocytic anaemias?
- Anaemia of renal failure
- Acute blood loss
- Bone marrow disease
- Anaemia of inflammation
What is the effect of bleeding on blood volume and blood pressure?
Causes reduced blood volume and falls blood pressure
What does the term ‘pancytopenia’ refer to?
Low levels of all major marrow cell types
What is a major consequence of chemotherapy on the marrow?
Pancytopenia
What is the effect of reduced erythropoietin (EPO) from diseased kidneys?
Leads to anaemia of renal disease
What are some risks associated with EPO abuse by athletes?
- Dangerous increase in Hb
- Increased blood viscosity
- Risk for clots
What can cause severe anaemia due to reduced red cell survival?
Haemolysis
What is polychromasia in the context of reticulocytes?
RNA appears blue in stained blood film
What are examples of haemolytic anaemias?
- Malaria
- Autoimmune
- Hereditary spherocytosis
What tests are used to diagnose haemolysis?
- Blood count
- Blood film examination
- Reticulocyte count
- Bilirubin levels
- Haptoglobin levels
What happens to haptoglobin levels during haemolysis?
Very low levels due to being used up
What is the consequence of non-functioning marrow?
Low levels of haemoglobin, platelets, and neutrophils
What should you do after self-studying cases?
Check answers and reinforce learning
