Anaemia Flashcards
(36 cards)
What is anaemia defined as?
Decrease in number of RBC, or decrease in oxygen-carrying capacity of blood cells
What are the mechanisms that can lead to anaemia?
- Decreased RBC production
- Increased RBC lysis
- Loss of blood
What is MCV?
Measurement of average volume of RBCs
What is a normal MCV?
80-100fl
What are the most common causes of microcytic anaemias?
- Iron deficiency anaemia
- Thalassaemia
What kind of anaemia is sideroblastic anaemia?
Generally microcytic, but may be normocytic
What are the causes of macrocytic anaemia?
B12 or folate deficiency. Alcohol excess or liver disease. Reticulocytosis eg with haemolysis Cytotoxics, eg hydroxycarbamide. Myelodysplastic syndromes. Marrow infiltration. Hypothyroidism. Antifolate drugs (eg phenytoin).
What are the causes of normocytic anaemia?
Acute blood loss. Anaemia of chronic disease (or ↓mcv). Bone marrow failure. Renal failure. Hypothyroidism (or ↑mcv). Haemolysis (or ↑mcv). Pregnancy.
In general, how might patients with anaemia present?
- Fatigue
- Dyspnoea
- Headaches
What is iron deficiency anaemia?
Anaemia caused by inadequate iron intake, which leads to decreased RBC production
Who is at the highest risk of iron deficiency anaemia?
Pre-menopausal women (due to menstrual loss)
What is the most common cause of iron deficiency anaemia in men and post-meno women?
GI bleeding
What are the main mechanisms of development of iron deficiency anaemia?
- Insufficient dietary intake or malabsorption of iron
- Increased loss of iron
- Increased demand for iron
When might there be malabsorption of iron?
Coeliac disease
When might there be increased loss of iron?
- GI bleeding
- Cancer
- UC
- Endemic infectious diseases, e.g. hookwork, schisto
When might there be increased demand for iron?
During pregnancy
What is Plummer-Vinson syndrome?
Triad of;
- Iron deficiency anaemia
- Oesophageal webs
- Dysphagia
What does treatment of Plummer-Vinson syndrome involve?
- Iron replacement
- Endoscopic dilatation of oesophagus
Why is careful assessment required in Plummer-Vinson syndrome?
Patients at higher risk of developing oesophageal carcinomas
What initial investigations are done in iron deficiency anaemia?
- FBC
- Peripheral smear
- Iron studies
What will be found on peripheral smear in iron deficiency anaemia?
Hypochromic (central pallor of RBC), microcytic anaemia
What is found on iron studies in iron deficiency anaemia?
Low iron levels, but increased total iron binding capacity
What other investigations may be done in iron deficiency anaemia?
- Endoscopy
- Coeliac screen
When should patients with iron deficiency anaemia be referred for urgent 2 week wait endoscopy?
- Over 60
- Under 50 with rectal bleeding
