Lab 5: evaluation of RBCs, anaemias

Question 1

normal Hgb range?

Answer 1

18-20 mmol/l

12-18g/dl (g%)

Question 2

how to measure for haemoglobin?

Answer 2

1. spectrophotometric method (Drabkin method)
2. rough estimation:
   
   • PCV/3 X 1000

Question 3

oxygen binding capacity of Hgb is increased by?

Answer 3

• reduced 2,3 DPG level in RBCs
• Reduced pCO2 pressure in the blood (e.g. respiratory alkalosis)
• increased blood PH (metabolic or respiratory alkalosis)
• decreased blood temperature ( Hypothermia)

Question 4

oxygen binding capacity of Hgb is reduced by?

Answer 4

• decreased 2,3 DPG concentration in RBCs
• increases pCO2 pressure in the blood (respiratory acidosis)
• decreased blood PH (metabolic or respiratory acidosis)
• increased blood temperature (hyperthermia)

Question 5

oxygen saturation of arterial and venous blood?

Answer 5

• Arterial = 95-100%

- venous = 80-90%

Question 6

what is methaemoglobin?

Answer 6

• Hgb molecules containing Fe of 3+ form
• cannot carry oxygen
• increase in concentration in the blood in the case of severe oxidative damage to RBCs (paracetamol, onions, free radicals)
• in this case the blood is chocolate brown

Question 7

causes of increased Hgb concentration?

Answer 7

• usually associated with relative (dehydration) or absolute
  polycythaemia

Question 8

causes of decreased Hgb?

Answer 8

• usually associated with relative (hyperhydration) or absolute oligocytaemia
  
  • Decreased RBC count
• Piglets have very low concentrations of Hgb

Question 9

measuring techniques for RBCs?

Answer 9

1. Burker chamber method
2. Estimated RBC count
   
   • Ht/5 x100 = RBC x10-12
3. RBC count using automatic cell counter
   
   • electronic impedance method

Question 10

Derivative RBC parameters?

Answer 10

• MCH
• MCV
• MCHC
• RDW

Question 11

what is needed to calculate RBC parameters?

Answer 11

• Ht or PCV
• RBC count
• Hgb concentration

Question 12

the equation for calculating MCH?

Answer 12

Hgb (g/l)/RBC count = MCH (pg)

Question 13

the equation for mean corpuscular volume?

Answer 13

PCV/RBC count x1000 = MCV (fl)

Question 14

normal range of MCH?

Answer 14

• 20-30 pg

Question 15

some causes of microcytosis?

Answer 15

• chronic blood loss
• iron, copper, pyridoxine deficiency
• portosystemic shunt

Question 16

some causes of macrocytosis?

Answer 16

• polycythaemia absoluta vera (erythroleukaemia)
• vit. B12, folic acid, cobalt deficiencies
• erythroleukaemias

Question 17

the equation for MCHC?

Answer 17

Hgb/PCV = MCH/MCV x1000 = MCHC

Question 18

MCHC normal range?

Answer 18

30-35%

Question 19

causes of decreased MCHC (hypochromasia)

Answer 19

• newborn animals
• regenerative anaemias
• iron deficiency anaemia

Question 20

causes for increases MCHC (hyperchromasia)

Answer 20

• Erythroleukaemias
• vit B12, folic acid, cobalt deficiencies
• immunehaemolytic anaemia
• lead poisoning
• splenectomy

Question 21

give the key features or reticulocyctes?

Answer 21

• immature RBCs
• not nucleated
• able to carry oxygen
• appearance in the bloodstream is a sign of regenerative function of the bone marrow

Question 22

normal reticulocyle count?

Answer 22

normally: 2-3% of RBCs

Question 23

causes for increased reticulocyte count?

Answer 23

• can be caused by different types of regenerative anaemias:
  
  • acute blood loss
  • Heamolytic anaemia
  • chronic blood loss
  • some types of nutrient deficient anaemias

Question 24

Osmotic resistance of RBCs is dependant on?

Answer 24

• PH pf the plasma (usually 7.4) and reagents
• temperature
• osmotic concentration of plasma and reagents
• RBC membrane status
• Regenerative status (reticulocytes more resistant)
• HbF (fetal haemoglobin) content of RBCs (more resistant)

Question 25

methods for measuring the osmotic resistance of RBCs?

Answer 25

1. make a dilution line from NaCl soloution from 0.3 - 2.5% - check for haemolysis 2. prepare a hypotonic solution from NaCl - check for haemolysis

Question 26

list the proper staining methods for RBCs?

Answer 26

1. Mar-grunwald staining 2. Giesma staining 3. Diff quick staining

Question 27

list the inclusion bodies?

Answer 27

1. Heinz body - denatured Hgb 2. Howell-jolly body - nuclear membrane remnants 3. Basophilic punctuates - nuclear remnants 4. Hgb inclusions

Question 28

list some RBC parasites?

Answer 28

- Babesia spp. - erlichia canis, Equi etc - Dirofilaria immitis repens - Anaplasia marginale - trypansosma evans

Question 29

what is the normal blood iron range?

Answer 29

-18-20micromol/l

Question 30

how is iron reduced?

Answer 30

- from unabsorbable Fe 3+ to absorbable Fe2+ by ascorbic acid in the duodenum

Question 31

causes of decreased iron concentration?

Answer 31

- reduced intake (calves, piglets) - chronic bleeding - impaired gastric, duodenal, jejunal function (reduced reduction, transport, absorption)

Question 32

causes of high iron concentration?

Answer 32

- iron overdose (iron toxicosis)

Question 33

what is TIBC?

Answer 33

serum iron level (saturated transferrin) + free transferrin (unsaturated)

Question 34

causes of low TIBC?

Answer 34

- chronic inflammation - chronic liver failure - neoplastic disease

Question 35

causes of high TIBC

Answer 35

- iron deficiency anaemia

Question 36

laboratory findings of haemolysis?

Answer 36

- PCV reduced - Polychromasia, polikilocytosis - leucocytosis - spherocytosis - total biliruben increased - indirect biliruben increased - lactate dehydrogenase (LDH) I, II increase - haptoglobin decrease - RBC osmotic resistance decrease - Jaundice - Hyperchromatic stool - higher than normal amount of haemoglobin - increased urobilinogen and Hgb in the urine