Anaemia Flashcards
What is anaemia?
A decrease in the amount of haemoglobin in the blood - <135g/L for men, <115g/L for women.
What could cause low Hb concentration?
Low red cell mass
Increased plasma volume
What is microcytic anaemia? What are the causes?
Mean cell volume (MCV) <80. Mainly iron-deficiency anaemia but also includes thalassemia and, rarely, sideoblastic anaemia.
What defines normocytic anaemia? What are the causes?
MCV 80-100. Acute blood loss, anaemia of chronic disease, combined haematicic deficiency (lecture 19.1.18)
What defines macrocytic anaemia? What are the causes?
MCV >100. B12 or folate deficiency (megaloblastic), alcohol excess/liver disease, metabolic disease eg hyperthyroidism.
What is thalassaemia?
A group of inherited blood disorders characterised by reduced haemoglobin production. The two main types are alpha and beta thalassaemias. (wiki, lecture)
How could chronic kidney disease cause anaemia?
Less EPO so fewer RBCs.
What causes iron deficiency?
Bleeding, malabsorption, poor diet, breastfeeding, hookworm. (pts)
What is the main diagnostic test for iron deficiency?
Measure serum ferritin. However, ferritin is an acute phase protein, so its concentration will increase in response to inflammation and malignancy, leading to false results.
What investigations would you do for suspected anaemia?
An endoscopy can be done to see if anaemia is due to a GI bleed.
Reticulocyte count tells you how quickly RBCs are being made in the bone marrow. Raised = problem with removal, eg bleeding, haemolytic anaemia. Low = problem with production eg iron deficiency anaemia.
What are the signs of iron deficiency?
Koilonychia (spoon-shaped nails), angular stomatitsi (ulcer at side of mouth), atrophic glossitis (atrophy of lingual papillae), brittle hair and nails.
How is iron deficiency anaemia treated? What are the side-effects?
Ferrous sulphate tablets.
Cause constipation, epigastric pain, diarrhoea, GI irritation.
What causes folate deficiency? and would this cause micro, normo or macrocytic anaemia?
Folate deficiency = macrocytic anaemia. Caused by malabsorption, increased demand (eg pregnancy), and poor diet (folate is in green veg, fruit)
What mainly causes B12 deficiency?
The most common cause of B12 deficiency is pernicious anaemia, in which autoimmune destruction of parietal cells results in decreased production of intrinsic factor. Since B12 needs to bind to IF to be absorbed, this leads to vitamin B12 malabsorption. (pts)
How is B12 deficiency treated?
Vitamin B12 injections or tablets. (pts)
How can crohn’s disease, coeliac disease and gastrectomy cause macrocytic anaemia?
B12 deficiency.
What are the symptoms of anaemia?
Fatigue
Faintness
Breathlessness
Reduced exercise tolerance
What are the signs of anaemia?
Pale skin, pale mucous membranes, tachycardia.
What is sickle cell anaemia?
A common type of sickle cell disease, which is a haemoglobinopathy in which the oxygen-carrying capacity of haemoglobin in red blood cells, causing them to become sickle-shaped.
Give 3 complications of sickle cell disease.
Chronic haemolytic anaemia Infections Painful 'sickle cell' crises Acute chest syndrome Ischaemic/haemorrhagic stroke Ocular disease (lecture)
How is sickle cell trait inherited?
Autosomal recessive inheritance.
What is the effect of having sickle cell trait?
Heterozygote advantage. It protects against falciparum malaria. Can also cause symptoms of sickle cell anaemia at high altitude.
What is Hbs?
Sickle haemoglobin.
Why does sickling occur?
The sickling only occurs in deoxygenated Hbs cells. It occurs more in:
acidosis, which decreases Hb affinity for O2,
low-flow vessels, because Hb has more time to deoxygenate.
What can cause low haptoglobin?
Repeated sickling weakens the RBC membrane so it breaks down in the blood. It is recycled by haptoglobin. When this is happening there is less free haptoglobin in the blood so low haptoglobin is a sign of sickle cell anaemia.
Why could a patient with sickle cell anaemia have jaundice, scleral icterus and bilirubin gallstones?
Increasing breakdown and recycling of haemoglobin creates lots of haem, which forms unconjugated bilirubin, which causes jaundice, scleral icterus and gallstones.
How does glucose-6-phosphate dehydrogenase deficiency cause anaemia and what type?
Inherited condition in which the body doesn’t have enough G6PD, which helps red blood cells (RBCs) function normally. This deficiency can cause haemolytic macrocytic anemia, usually after exposure to certain medications, foods, or infections.
