Lab 1 - Isovolaemia, isoosmosis: PCV, ion concentrations

Question 1

Give an example of a clotting activator

Answer 1

Si-oxide

Question 2

In haematology, which substances are used as anticoagulants?

Answer 2

1. Na2 (Disodium)
2. K2 (Dipotassium)
3. EDTA (NaK-ethylene-diamine-tetraacetic acid)

Question 3

How does EDTA inhibit coagulation?

Answer 3

By irreversibly binding Ca²⁺ to the sample

Question 4

How much EDTA is added to 1ml of full blood?

Answer 4

1.5-2 mg

Question 5

How long does it take for the blood+EDTA sample to swell?

Answer 5

12 hours

Question 6

Blood biochemistry parameters are mostly evaluated in the…

Answer 6

Serum

Question 7

Naturally, in blood plasma, coagulation is blocked by…

Answer 7

Heparin

Question 8

Function of Heparin

Answer 8

Enhances:

• Binding of coagulation factors → antithrombin III
• Blocks fibrinogen → fibrin as a result

Question 9

Heparin is produced by…

Answer 9

Mast cells

Question 10

Give the volume ratio for heparin : blood

Answer 10

1 drop heparin : 5ml blood

Question 11

Why is lyophilised (freeze-dried) heparin used for this experiment?

Answer 11

Prepared heparin has a diluting effect, blocking ionised Ca²⁺ over time

Question 12

Heparin has a … effect on WBCs in vitro

Answer 12

Necrotising

Question 13

What is used as an anticoagulant for the testing of blood clotting parameters?

Answer 13

Na₂-Citrate (3.8% solution)

Question 14

Give the ratio of Na₂-citrate : blood for haemostasis evaluations

Answer 14

1:9

Question 15

Give the mode of action for Na₂-Citrate

Answer 15

Reversibly binds Ca²⁺ to the sample

Question 16

Give the Na₂-Citrate:Blood ratio when used in cell sedimentation

Answer 16

1:4

Question 17

Define isovolaemia

Answer 17

The physiological and pathological alterations of fluid volume

Question 18

Give the volume of water: Total in body

Answer 18

600-650 ml/BWkg

Question 19

Give the volume of water: EC space

Answer 19

250-300 ml/BWkg

Question 20

Give the volume of water: IC space

Answer 20

350-400 ml/BWkg

Question 21

Give the two kinds of volume disturbances

Answer 21

• Perfusion disorders
• Hydration disorders

Question 22

A decrease of tissue perfusion means a volume deficit in the…

Answer 22

Intravascular space

Question 23

Clinical signs used to evaluate perfusion

Answer 23

1. CRT (capillary refill time) Hypovolaemia↓; Hyper- ↑
2. Mucous membrane colour
3. Pulse strength
4. Heart rate
5. BP

Question 24

Clinical signs used to evaluate hydration

Answer 24

1. Skin turgor (easticity)
2. Eye turgor
3. Mucous membranes
4. Sunken eyes (Prolapse of the third eyelid in fe.)
5. Skin around the oral cavity/anus (signs of water loss)
6. BW changes
7. Urine production; specific gravity of urine

Question 25

Give the types of volume-disturbance evaluation

Answer 25

1. Clinical signs 2. Based on PCV (Packed cell volume; Ht) 3. Based on Hb conc. 4. Based on plasma TP (total protein)/ Albumin conc. 5. Based on change in MCV (mean corpuscular vol.) of RBC

Question 26

CRT (Capillary refill time) during: * Dehydration * Hyperhydration

Answer 26

* Dehydration: ↑ * Hyperhydration: - / ↓

Question 27

Strength of pulse during: * Dehydration * Hyperhydration

Answer 27

* Dehydration: ↓ * Hyperhydration: ↑

Question 28

Bodyweight during: * Dehydration * Hyperhydration

Answer 28

* Dehydration: ↓ * Hyperhydration: - / ↑

Question 29

Mucous membranes during: * Dehydration * Hyperhydration

Answer 29

* Dehydration: Dry * Hyperhydration: No change/oedema

Question 30

The elasticity of the skin during: * Dehydration * Hyperhydration

Answer 30

* Dehydration: ↓ * Hyperhydration: No change/oedema

Question 31

Placement of the eyeballs during: * Dehydration * Hyperhydration

Answer 31

* Dehydration: Enophthalmos * Hyperhydration: No change/exophthalmos

Question 32

Turgor of the eyes during: * Dehydration * Hyperhydration

Answer 32

* Dehydration: ↓ * Hyperhydration: - / ↑

Question 33

Heart rate during: * Dehydration * Hyperhydration

Answer 33

* Dehydration: ↑ * Hyperhydration: - / ↑

Question 34

Central venous BP during: * Dehydration * Hyperhydration

Answer 34

* Dehydration: ↓ * Hyperhydration: Normal / ↑

Question 35

Hb conc. during: * Dehydration * Hyperhydration

Answer 35

* Dehydration: ↑ * Hyperhydration: ↓

Question 36

PCV (Ht) during: * Dehydration * Hyperhydration

Answer 36

* Dehydration: ↑ * Hyperhydration: ↓

Question 37

TP and/or Albumin during: * Dehydration * Hyperhydration

Answer 37

* Dehydration: ↑ * Hyperhydration: ↓

Question 38

MCV during: * Dehydration * Hyperhydration

Answer 38

* Dehydration: ↓ (Hyperosmosis) * Hyperhydration: ↑ (Hypoosmosis)

Question 39

Osmolality (serum, urine) during: * Dehydration * Hyperhydration

Answer 39

* Dehydration: ↑ (Hyperosmosis) * Hyperhydration: ↓ (Hypoosmosis)

Question 40

Urine output during: * Dehydration * Hyperhydration

Answer 40

* Dehydration: ↓ * Hyperhydration: ↑

Question 41

Urine specific gravity during: * Dehydration * Hyperhydration

Answer 41

* Dehydration: ↑ * Hyperhydration: ↓

Question 42

Clinical signs of 5-15% blood loss

Answer 42

No change in BP

Question 43

Clinical signs of 15-25% blood loss

Answer 43

* Tachycardia * Vasoconstriction * Initial BP ↑

Question 44

Clinical signs of 35-45% blood loss

Answer 44

* Severe BP ↓ * Oliguria/anuria * Vasodilation * Shock

Question 45

Clinical signs of 50% blood loss

Answer 45

Death

Question 46

Packed cell volume (PCV)/Haematocrit

Answer 46

Ratio of whole blood volume : volume of RBCs

Question 47

PCV is used to evaluate...

Answer 47

* Fluid volume changes * Quantitative changes of RBCs

Question 48

PCV samples should be...

Answer 48

Anticoagulated

Question 49

Methods of PCV measurement

Answer 49

1. Microhematocrit/Microcapillary method 2. Use of automated cell counter 3. Handheld HCT meter

Question 50

Ht samples should be centrifuged at...rpm

Answer 50

12,000

Question 51

Automated cell counters use which formula?

Answer 51

Question 52

HCT meters measure...

Answer 52

* Ht *(given as a percentage)* * Total haemoglobin

Question 53

HCT meters giving a result of "LO" mean the Ht is lower than...%

Answer 53

10%

Question 54

Give the physiological range of PCV in most species

Answer 54

* 0.35-0.45 l/l or * 35-45%

Question 55

Decrease of PCV

Answer 55

Oligocythaema/anaemia

Question 56

Increase of PCV

Answer 56

Polycythaemia

Question 57

Incidences where hypovolemic normocythemia may occur

Answer 57

* During/after acute blood loss * Shock

Question 58

Incidences where hypervolemic normocythemia may occur

Answer 58

* Overdosing of full blood transfusion * Chronic stress

Question 59

False polycythaemia

Answer 59

1. Long sample storage with EDTA 2. RBC corpuscular volume ↑

Question 60

Physiological polycythemia types

Answer 60

* Congenital polycythemia * Age-related polycythemia * Physiological long-term hypoxia

Question 61

Congenital polycythemia

Answer 61

Species and breed characteristics * Llama * Yak * Greyhound * Whippet * Borzoi * Hot-blooded horses

Question 62

Age-related polycythemia is observed in...

Answer 62

Newborn animals

Question 63

Physiological long-term hypoxia

Answer 63

* Normovolaemic polycythemia * Living in a high altitude * Regular intensive long training/work * E.g Sled dogs

Question 64

Relative polycythaemia

Answer 64

Decreased plasma volume ## Footnote *Through dehydration (hypovolaemic polycythemia)*

Question 65

Absolute polycythemia

Answer 65

Increased RBC production * Primary * Secondary

Question 66

Primary Absolute polycythemia

Answer 66

_Without_ increased erythropoietin (EPO)

Question 67

Secondary absolute polycythaemia

Answer 67

Due to increased erythropoietin (EPO)

Question 68

Secondary absolute polycythaemia can be either...

Answer 68

* True * Not-true

Question 69

True secondary polycythaemia

Answer 69

* Caused by long term hypoxia * ROA - Recurrent airway obstruction in horses * Right-left shunt in the heart * Due to chronic resp./circulatory disorders * E.g Brachycephalics

Question 70

Non-true secondary polycythaemia

Answer 70

Without hypoxia * Autonomous increase of EPO

Question 71

Hypervolaemic polycythaemia

Answer 71

Life-threatening acute stress or extreme physical exercise

Question 72

Give the types of polycythemia

Answer 72

* False polycythemia * Physiological polycythemia * Relative polycythemia * Absolute polycythemia * Hypervolaemic polycythemia

Question 73

Give the causes of oligocythaemia

Answer 73

* False oligocythaemia * Physiological oligocythaemia * Relative oligocythaemia * Absolute oligocythaemia

Question 74

False oligocythaemia causes

Answer 74

* Microcytosis (decreased RBC volume) * Inappropriate sample homogenisation

Question 75

Physiological oligocythaemia causes

Answer 75

Plasma volume in the third trimester of pregnancy ↑