Case 7 Sem 2

Question 1

Functions of blood

Answer 1

Distribution: oxygen and nutrients (removes waste products), hormones to target organs, blood cells and platelets
Regulation: body temp, pH, solutes, restricts osmosis into tissue
Protection: against blood/fluid loss via homeostasis, against infection via contributing to inflammatory and immune response

Question 2

What remains in blood after cellular components removed?

Answer 2

Plasma

Question 3

Red blood cell production

Answer 3

Produced in bone marrow by division and differentiation from stem cells
Regulated by erythropoietin
Regulatory factors including iron, amino acids, B12 and folic acid (B9)

Question 4

Erythropoietin

Answer 4

Produced by kidney in response to low oxygen levels, regulates RBC production

Question 5

Red blood cell features

Answer 5

Biconvave disc, anucleated, 120 days, RBC conc. remains at 5 million / uL
Senescent RBC cleared by macrophages of spleen, liver and marrow (erythrophagocytosis) at rate of 5 million/ second

Question 6

Haemoglobin

Answer 6

Each molecule of haem contains Fe2+
Each haem binds one molecule of oxygen
Each haem sits with peptide chain (globin)
Adult haemoglobin (HbA) consists of 2 alpha and 2 beta chains

Question 7

Anaemia

Answer 7

Reduction in haemoglobin concentration
Females: <120g/L
Males: <130g/L

Question 8

Symptoms of anaemia

Answer 8

Fatigue, weakness, reduced energy/exercise tolerance, shortness of breath, palpitations, dizziness, irritability, impaired concentration

Question 9

Causes of anaemia

Answer 9

Failure of RBC production: deficiency in iron, B12, folate/congenital and acquired bone marrow disorders, liver and renal disease, drug and alcohol use
Defective red cells: haemoglobinopathy - sickle cell disease, thalassaemia
RBC membrane/enzyme disorder - G6PD deficiency, pyre age kinase deficiency
Loss or destruction of RBC: blood loss (acute/chronic), haemolysis - abnormal breakdown of RBC

Question 10

Symptoms of anaemia (taking a history)

Answer 10

Menorrhagia, change in bowel habit, urine, weight loss, fevers/infections, inflammatory bowl disease/coeliacs/varied diet (malabsorption and diet), medication, drugs, alcohol, family history of anaemias

Question 11

Blood tests

Answer 11

Full blood count: haemoglobin conc, mean corpuscular volume, haemtocrit
Iron studies: ferritin, serum iron, total iron binding capacity, iron/transferrin saturations
Retixulocyte count
B12 and folate

Question 12

Haemoglobin concentration

Answer 12

Concentration of haemoglobin in whole blood
Normal: 120-160g/L
Female: 130g-180g/L

Question 13

Mean corpuscular volume

Answer 13

Average size of RBC
Normal range: 80-100

Question 14

Haemtocrit

Answer 14

Proportion of red cell: whole blood
Male: 41-50%
Female: 36-4f%

Question 15

Iron deficiency

Answer 15

See through pale RBC under microscope
Low ferritin (normal does not exclude)
Low iron or transferrin saturations
Angular cheilosis (around corners of mouth)
Koilonychia (nail curved)
Need to consider underlying cause

Question 16

Macrocytic anaemia

Answer 16

B12 or folate deficiency
Alcohol
Liver disease
Drugs - purine analogues, trimethoprim, hydroxycarbamide, methotrexate, come antiepileptics, oral contraceptives
Bone marrow failure / myelodysplasia (cells to not mature)

Question 17

What is haemolytic anaemia

Answer 17

Premature breakdown of RBC

Question 18

Features of haemolysis

Answer 18

Raised bilirubin (unconjugated)
Raised reticulocyte count
Raised LDH
Low haptoglobin

Question 19

Causes of haemolytic anaemia

Answer 19

Immune - antibody against RBC
haemolytic transfusion reaction
Drug related
Structural defect in haemoglobin

Question 20

Inherited anaemias

Answer 20

Haemoglobin disorders: sickle cell disease, thalassaemia syndromes
Membrane disorders: soherocytosis, elliptocytosis, stomatocytosis
Enzyme disorders: G6PD deficiency, pyruvate kinase deficiency

Question 21

Thalassaemia

Answer 21

A group of inherited disorders resulting in reduced production of one or more globin chains