MP323 - HAEMATOLOGICAL DISORDERS

Question 1

erythropoiesis

Answer 1

RBC production, stimulated by hypoxia, controlled by erythropoietin (hormone synthesised in kidney)

Question 2

Haemolysis

Answer 2

• destruction of RBCs
• releases bilirubin into bloodstream
• normal lifespan of RBC = 120 days

Question 3

anticoagulation

Answer 3

• elements that interfere with blood clotting
• aspirin
• clopidogrel
• warfarin
• heparin

Question 4

Leukopenia

Answer 4

decreased WBCs

Question 5

neutropenia

Answer 5

decreased neutrophil count

Question 6

RBC count for women and men

Answer 6

women = 4.5 - 5.5 x10^6
men = 4.0 - 5.0 x10^6

Question 7

Haematocrit (Hct)

Answer 7

percentage of whole blood that is composed of red blood cells

measures the number the RBCs and the size of red blood cells

Question 8

normal platelet count

Answer 8

150,000 - 400,000

spontaneous haemorrhage likely when <20,000

Question 9

thrombocytopenia

Answer 9

decreased platelet count

Question 10

pancytopenia

Answer 10

decreased number of RBCs, WBCs and platelets

Question 11

anaemia

Answer 11

• reduction in RBCs, the quantity of haemoglobin, or the volume of RBCs
• main function of RBCs is oxygenation, anaemia results in varying degrees of hypoxia
• drives ischaemic pathologies

Question 12

prevalent conditions in anaemia

Answer 12

• blood loss
• decreased production of erythrocytes
• increased destruction of erythorcyes

Question 13

symptoms of anaemia

Answer 13

• PALLOR
• fatigue, weakness
• dyspnoea
• palpitations, tachycardia
• headache, dizziness and restlessness
• slowing of thought
• paraesthesia

Question 14

aetiology of iron-deficiency anaemia

Answer 14

DECREASED ERYTHROCYTE PRODUCTION
- inadequate dietary intake
- malabsorption
- blood loss
- haemolysis

Question 15

common symptoms of iron-deficiency anaemia

Answer 15

• pallor and glossitis (inflamed tongue)
• cheilitis
• sensitivity to clod
• weakness and datigue

Question 16

diagnostic studies for iron-deficiency anaemia

Answer 16

• FBC
• iron levels: total iron-binding capacity (TIBC) and serum ferritin
• endoscopy/colonoscopy

Question 17

iron replacement for iron-deficiency anaemia

Answer 17

• oral iron
• ferrous sulphate
• absorbed best in acidic environment

Question 18

side effects of oral ferrous sulphate for iron-deficiency anaemia

Answer 18

• constipation/diarrhoea
• GI discomfort
• nausea

can be taken after food to reduce GI side-effects but best absorbed on empty stomach

Question 19

megaloblastic anaemias

Answer 19

• characterised by large RBCs which are fragile and easily destroyed

common forms: cobalamin deficiency, folic acid deficiency

Question 20

causes of cobalamin (vitamin B12) deficiency

Answer 20

• gastric mucosa not secreting intrinsic factor
• long-term use of H2 histamine receptor blockers cause atrophy or loss of gastric mucosa
• nutritional deficiency
• hereditary defects

Question 21

common symptoms of cobalamin deficiency anaemia

Answer 21

• general symptoms of anaemia
• sore tongue
• anorexia
• weakness
• paraesthesia
• altered thought processes

Question 22

diagnostic studies of B12 deficiency anaemia

Answer 22

• RBCs appear large
• abnormal shapes
• structure contributes to erythrocyte destruction

Question 23

treatment for B12 pernicious anaemia

Answer 23

• oral cyanocobalamin
• parental cobalamin
• dietary intake is important

Question 24

characteristics of folic acid deficiency

Answer 24

• RBCs that are large and fewer in number
• folic acid required for RBC formation and maturation

Question 25

causes of folic acid deficiency

Answer 25

- poor dietary intake - malabsorption syndromes - drugs that inhibit absorption - alcohol abuse - haemodialysis

Question 26

characteristics of anaemia of chronic disease

Answer 26

- underproduction of RBCs, shortening of RBC survival - 2nd most common cause of anaemia - generally develops after 1-2 months of sustained disease

Question 27

causes of anaemia of chronic disease

Answer 27

- impaired renal function - chronic, inflammatory, infectious or malignant disease - chronic liver disease - folic acid deficiencies - splenomegaly - hepatitis

Question 28

anaemia caused by acute blood loss

Answer 28

result of sudden haemorrhage (trauma, surgery, vascular disruption)

Question 28

care for anaemia caused by acute blood loss

Answer 28

1. replacing blood volume 2. identifying source of haemorrhage 3. stopping blood loss

Question 28

chronic blood loss sources/symptoms

Answer 28

- similar to iron-deficiency anaemia - GI bleeding, haemorrhoids, menstrual blood loss

Question 29

care for chronic blood loss

Answer 29

supplemental iron administration

Question 30

types of anaemia caused by increased erythrocyte destruction

Answer 30

- haemolytic anaemia - sickle cell anaemia - haemochromatosis - polycythemia

Question 31

haemolytic anaemia characteristics

Answer 31

- destruction or haemolytic of RBCs at a rate that exceeds production - third major cause of anaemia

Question 32

intrinsic haemolytic anaemia

Answer 32

- abnormal haemoglobin - enzyme deficiencies - RBC membrane abnormalities

Question 33

extrinsic haemolytic anaemia

Answer 33

- normal RBCs - damaged by external factors (liver, spleen, toxins, mechanical injury)