Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Lab D > Lab 2 > Flashcards

Lab 2 Flashcards

1
Q

The most important physico-chemical buffer system in all fluid compartments of the body?

A

the carbonic acid - bicarbonate system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What forms the Vital buffer system?

A

the kidneys and the lungs.

They are continually closely interacting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

explain the Buffering capacity of the lungs:

A

the lungs can retain the CO2, or excrete it to regulate the pH acutely.
Ex: Increased H+ (reduced ECF pH): the equation will move to the left, generating extra CO2, lead to hypercapnia, which stimulate the ventilation and the lungs can eliminate the CO2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Kussmaul breathing?

A

is observed because the pulmonary capacity to excrete CO2 is huge. Normal frequency of breathing but very deep inspiration and expiration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Explain buffering capacity of the kidneys:

A

The kidneys can excrete or retain H+, and also effectively regenerate the HCO3- via complex tubular mechanisms - takes hours/days.
Ex: If CO2 levels within the body increase, the equation will push to the right, and produce excess H+ and HCO3-, and then H+ can be eliminated by the kidneys.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What kind of sample is necessary for acid/base analysis?

A

anticoagulated blood (Ca-equilibrated Li-heparinised syringe).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why is arterial samples essential?

A

for assessment of respiratory function, but either venous or arterial samples can provide useful information on the metabolic status of the animal.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the “Astrup-technique”?

A

A closed sampling method to avoid air contamination of the sample.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What can happen in air contaminated samples?

A
  • pO2 will be increased (150mmHg pO2 is in atmospheric air)
  • pCO2 may be decreased (shortly after samling as CO2 evaporates into the air
  • pCO2 may be increased (in case of longer storage, produced by the metabolism of blood cells)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How should the samples be stored?

A

Not more than 5-10 min at room temp. and not more than 30 min at 0-4*C (refrigerator)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What method is used for Acid/base analysis?

A

analyzers utilize ionselective electrodes (ISE) to measure pH and CO2. Based on the measured parameters the HCO3-, ABE and other parameters are calculated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What temperature are the samples analyzed at?

A

37*C

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

the solubility of gases is dependent on?

A

temperature, and the measured values need to be corrected to the temperature of the patient.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Routinely used acid-base parameters:

- pH

A

7.35-7.45

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Routinely used acid-base parameters:

- pCO2

A

40 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Routinely used acid-base parameters:

- ABE

A

+-3.5 mmol/l

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Routinely used acid-base parameters:

- TCO2

A

23-30 mmol/l

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Routinely used acid-base parameters:

- SBE

A

+-3 mmol/l

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Evaluation of AB state:

- Step 1

A

Evaluate wheter acidosis or alkalosis is present according to the pH!

  • Blood pH reference range
  • pH <7.35 acidosis is decompensated
  • pH >7.45 alkalosis is decompensated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Evaluation of AB state:

- Step 2

A

Search for the cause of the observed pH alteration

  • The predominant change of pCO2 refers to primary respiration
  • the predominant change of HCO3- and ABE refers to primary metabolic processes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Respiratory background of pH alterations:

A

pCO2 shows a strong shift in the same direction as the pH.

- When pCO2 is >40mmHg, more of it bounds to water and forms carbonic acid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Increase of pCO2 in respiration can be called?

A

A shift in “acidic” direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What happens in case of impaired gas exchange in the lungs?

A

the remaining high CO2 forms carbonic acid and shifts the pH to acidosis: respiratory acidosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What happens during hyperventilation?

A

too much CO2 is exhaled which will cause elevation of the pH: respiratory alkalosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Metabolic background of pH alterations:

A

Eg: in case of lactic acid production metabolic acidosis occurs, both metabolic parameters are shifted in acidic direction.
- HCO3- being an anion decreases in acidosis and increases in alkalosis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Calculation of Actual base excess:

A

is a calculated parameter which was defined to aid correction of acid-base disturbances.
- when metabolic alkalosis is seen this paramter shifts from 0 to the positive range: in metabolic acidosis to negative range.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

How is compensatory effect detected:

A

the given parameter is shifted in opposite direction compared to the pH.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is “mixed acidosis”

A

sometimes all parameters are shifted significantly in the same direction as the pH - this is observed mostly in advanced acidosis.

29
Q

Evaluation of AB state:

- Step 3

A

Evaluate whether compensation effort is visible in the result or not!
- If either the respiratory or the metabolic parameters is shifted in the opposite directin than the pH - the compensatory effect is visible
Eg: in metabolic acidosis the lungs try ot compensate by highly effective gas exchange; very deep breath and longer gas exchange (Kussmaul breathing)

30
Q

Kussmaul breathing helps to:

A

excrete alot of CO2, so pH is acidic and CO2 changes alkaline direction.

31
Q

Metabolic acidosis

- Causes:

A
  • HCO3- loss: diarrhoea, ileus, kidney tubular disturbance
  • Increased acid intake: fruits, too acidic silage, overdose of acidifying drugs, Vitamin C.
  • Increased acid production: increased lactic acid production, anaerobic glycolysis, frequent in anorectic, weak animals.
  • In cattle grain overdose: volatile acid overproduction
  • Increased ketogenesis: leading to ketosis due to relative or objective starvation or diabetes mellitus
  • Decreased acid excretion: renal failure
  • Ion exchange: hyperkalaemia (H/K pump!!)
  • Some xenobiotic: ethylene-glycol toxicosis: metabolies are acidic molecules, leading to metabolic acidosis, and finally renal failure will worsen it.
32
Q

Metabolic acidosis

- Effects:

A
  • Kussmaul-type breathing - hyperventilation
  • Hypercalcaemia: increased mobilisation from bones in case of long term acidosis (TCa), and decreased binding of calcium ions to albumin (Ca2+)
  • Hyperkaaemia: decreased cardiac muscle activity; sinoatrial, or atrioventricular block, bradycardia
33
Q

Metabolic acidosis

- Treatment:

A
  • providing adequate ventilation

- if pH <7.2 infusion therapy involving alkaline fluid

34
Q

What is the Anion gap?

A

a useful parameter when attempting to determine the cause of metabolic acidosis. The anion gap describes the difference between the commonly measured cations in plasma, and the commonly measured anions.

35
Q

reference range for anion gap:

A

8-19 mmol/l

36
Q

Metabolic alkalosis

- Causes:

A
  • Increased alkaline intake: overdose of bicarbonates, or feeding rotten food
  • increased ruminal alkaline production: high protein intake, low carbohydrate intake, anorexia, hypomotility
  • Decreased hepatic ammonia catabolism (liver failure
  • Increased acid loss: vomitting, gastric dilatation volvulus syndrome, abomasal displacement.
  • Ion exchange: hypokalaemia; due to Henle loop diuretics (H/K PUMP!!)
37
Q

Metabolic alkalosis

- Effects:

A
  • Breathing depression (compensatory respiratory acidosis), low breathing rate, hypoventilateion
  • Muscle weakness, hypokalaemia
  • Hypocalcaemia due to increased Ca2+ binding of albumin
  • Ammonia toxicosis
  • Arrythmia, biphasic P, QT increased (AV conduction disorder), flat T, U wave
  • Paradoxical aciduria
38
Q

Respiratory acidosis

- Causes

A
  • Upper airway obstruction
  • Pleural cavity disease: pleural effusion, pneumothorax
  • Pulmonary disease: severe pneumonia, pulmonary oedema, diffuse lung metastasis, pulmonary thromboembolism
  • depression of central control of respiration: drugs, toxins, brainstem disease
  • neuromuscular depression of respiratory muscles
  • muscle weakness eg muscle weakness in hypokalaemia
  • cardiopulmonary arrest
39
Q

Respiratory acidosis

- effects:

A
  • Dyspnoea, cyanosis, suffocation, muscle weakness, tiredness
40
Q

Respiratory acidosis

- treatment:

A
  • assist the ventilation, providing fresh air r oxygen therapy
  • treatment of the cause: e.g diuretic treatment; in case of fluid accumulation in the lungs, pulmonary oedema; specific cardiologic treatment; in case of underlying cardiac disaease; treatment of pneumonia, removal of luid from pleural space
  • mildly anxiolytic/sedating drugs to decrease the fear and excitement of animals caused by hypoxia
41
Q

Respiratory alkalosis

- Causes:

A
  • Increased loss of CO2: hyperventilation, excitation, forced ventilation (anasthesia), epiletiform seizures, fever, hyperthermia, interstitial lung disease.
42
Q

Respiratory alkalosis

- effects:

A
  • Hyperoxia, increased pCO2: pO2 ratio, may lead to apnoea

- increased elimination of HCO3- by the kidneys

43
Q

Respiratory alkalosis

- treatment:

A
  • anxiolytic or mild sedative drugs in case of hyperexcitation. it is important to increase the pCO2 level by closing nose or nostrils, pulling paper sack on the nose until breathing normalizes
44
Q

Indication/goal of Blood gas analysis?

A

is performed to assess effectiveness of gas-exchange i.e ventilation in the lungs e.g during dyspnoea or anasthesia

45
Q

Sample used for Blood gas analysis?

A
  • Arterial samples: precise assessment of respiratory function, i.e how effective the gas exchange in the alveoli is.
  • Venous: reflects gross changes only and gives information about how much oxygen is consumed by the body.
46
Q

Sampling used for Blood gas analysis?

A
  • Anticoagulated blood

- Ca-equilibrated Li-heparinised plasma, preheparinised syringe

47
Q

Why must the Astrup Technique be used?

A

because transferring blood to a tube will alter the partial pressure of gases, therefore a closed sampling method should be used.
- the sample must be stored with no air/vacuum space, because the CO2 can evaporate and air contamination causes false increased p=2 pressure.

48
Q

How to measure Blood gas analysis?

A

within 15 minutes, or placed on ice, to minimize changes in blood gas partial pressure as a result of continued metabolism.

49
Q

Method of analyzing Blood gas?

A

The blood gas anaylzers directly measure the pCO2 and pO2 with ion specific electrodes. The samples are analyzed on standaridized temperature 37*C.

50
Q

Parameters and reference range:

- paO2

A

88-118 mmHg

51
Q

Parameters and reference range:

- paCO2

A

35-45 mmHg

52
Q

Parameters and reference range:

- SAT or SatO2

A

Venous: 75-80&
Arterial: 90-100%

53
Q

Parameters and reference range:

- FiO2

A

Room air: 0.209 (20.9%)
O2 enriched: 0.21-1.0
>0.5 risk of O2 toxicity

54
Q

What are the most important parameters to assess the fas exchange capacity of the animals?

A

paO2 and paCO2
- Following conclusions can be frawn for the overall effectiveness: normoventilation, hypoventilation or hyperventilation

55
Q

Normal arterial oxygen pressure (paO2) at room air:

A

80-110 mmHg

The saturation is around 97-100%

56
Q

When is cyanosis detectable?

A

Under 40-50 mmHg

57
Q

What is higher, pvCO2 or paCO2?

A

Normal pvCO2 is higher than paCO2

58
Q

Hypoventilation is when paCO2 is?

A

> 45 mmHg

59
Q

Hypoxaemia depends on?

A

the degree of hypercapnia and the FiO2

60
Q

Hypoventilation

- Causes:

A
  • upper airway obstruction
  • pleural effusion
  • drugs or disorder affecting central control of respiration e.g: general anasthesia
  • neuromuscular disease, which affects on respiratory system, also muscle weakness e.g: hypokalaemia
  • overcompensation of metabolic alkalosis
61
Q

Hypoventilation

- Effects, signs:

A

Dyspnoea, cyanosis

62
Q

Hypoventilation

- Treatment

A
  • assisting the ventilation e.g: oxygen therapy
  • diuretic treatment: in case of fluid accumulation in the lungs, pulmonary oedema; or in the thoracic cavity
  • mildly anxiolytic/sedating treatment
63
Q

What is VA/Q?

A

Additional to hypoventilation arterial blood gas tensions are also influenced by Ventilation-Perfusion Mismatch(VA/Q)

  • normal ventilation with inadequate perfusion (insufficient blood passing the alveoli for oxygen)
  • inadequate ventilation with normal perfusion (pulmonary capillary blood reaches the alveoli adequate quantities, but ventilation those alveoli has been insufficient to allow enough oxygen
64
Q

Hyperventilation is when paCO2 is?

A

< 35mmHg

65
Q

Hyperoxaemia usually present together with?

A

increased SAT

66
Q

Hyperventilation

- Causes:

A
  • iatrogen: forced ventilation during anaesthesia (also high FiO2)
  • seizures, epilepsy
  • excitation (mild frequently visiting the vet, extreme e.g shock after accident)
67
Q

Oxygen saturation in venous blood informs about?

A

tissue O2 usage and venous SAT below 60% indicates that the body is in lack of oxygen, and ischemic disease occur.

68
Q

The “acid-base” or “blood-gas” analyzers include ion specific electrodes for:

A

pH, CO2, HCO3- and also ions: Ca2+, Na+, K+, Cl-.
When we interpret the result given by the analyzer we have to interpret all three evaluations: acid-base parameters, blood gas analysis and ionogram!

Lab D (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions