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Flashcards in Biochemistry Deck (67):
1

Where is most of [H+] in our body excreted?

Via urine

2

Is urine acidic or alkaline?

Acidic

3

Is buffering of H+ a temporary measure?

Yes

4

Give the bicarbonate equation.

[H+] + HCO3 = H2CO3 = CO2 + H2O

5

What is carbonic acid (H2CO3) removed as?

CO2

6

What is the equation which underpins all acid-base stuff?

[H+] (alpha sign) (pCO2/[HCO3])

7

What is the solution for too much H+ or too much CO2?

Compensation

8

When you've got too much H+, what occurs as compensation?

Lungs blow off CO2

9

When you've got too much CO2, what occurs as compensation?

The kidneys get rid of [H+]

10

What is acidaemia?

Increased [H+]

11

What is alkalaemia?

Decreased [H+]

12

What does acidosis tend to cause?

Increased [H+]

13

What does alkalosis tend to cause?

Decreased [H+]

14

What is the respiratory component?

pCO2

15

What is the metabolic component?

HCO3

16

What is an increase in [H+], due to increase pCO2?

Respiratory acidosis

17

What is a decrease in [H+], due to decreased pCO2?

Respiratory alkalosis

18

What is increased [H+], due to decreased HCO3?

Metabolic acidosis

19

What is decreased [H+], due to increased HCO3?

Metabolic alkalosis

20

What is the respiratory compensation for metabolic acidosis?

Blow off CO2

21

What is the metabolic compensation for respiratory acidosis?

Excrete more H+

22

What is the compensatory response for increased pCO2 (respiratory acidosis)?

Increased HCO3

23

What is the compensatory response for decreased pCO2 (Respiratory alkalosis)?

Decreased HCO3

24

What is the compensatory response for decreased HCO3 (metabolic acidosis)?

Decreased pCO2

25

What is the compensatory response for increased HCO3 (metabolic alkalosis)?

Increased PCO2

26

What are the 4 arterial blood gases?

H+
pCO2
HCO3
pO2

27

Give three causes of respiratory acidosis?

Choking
Bronchopneumonia
COAD

28

Give three causes for respiratory alkalosis?

Hysterical over-breathing
Mechanical over-ventialtion
Raised intracranial pressure

29

Give three causes of metabolic acidosis?

Imparied [H+] excretion
Increased [H+] production or ingestion
Loss of HCO3

30

Give three causes of metabolic alkalosis?

Loss of [H+] in vomit
Alkali ingestion
Potassium deficiency

31

What is the normal range of pH?

7.35 - 7.45

32

What must PaO2 always be interpreted against?

The inspired O2

33

What is PaO2?

the partial pressure of oxygen in arterial blood

34

What is the normal range breathing air of PaO2?

9.3 - 13.3 kPa

35

What is the normal range for PaCO2?

4.7 - 6 kPa

36

The body tries to compensate for a metabolic alkalosis by raising PaCO2, what does the body do physically?

Hypoventilating

37

The body will try to compensate for a metabolic acidosis by lowering PaCO2, what does the body do physically?

Hyperventialte

38

What is the normal range of base excess?

-2 to +2 mmol/l

39

What is base escess?

The measure of how much base has to be removed or added to the system to correct the pH in standard conditions. It is a measure of metabolic acidosis or alkalosis.

40

What does a negative BE indicate?

Metabolic acidosis

41

What does a positive BE indicate?

Metabolic alkalosis

42

What does the kidney do to compensate for respiratory acidosis?

Creates a metabolic alkalosis by retaining bicarbonate

43

What does the kidney do to compensate for respiratory alkalosis?

Creates a metabolic acidosis by excreting bicarbonate

44

What does hypercapnic mean?

High pCO2

45

What is polydipsia?

Excessive thirst

46

If the patient has metabolic acidosis, and the pCO2 is normal, what does this indicate?

No respiratory compensation

47

What is hypoxia?

Lack of oxygen

48

What is hypoxaemia?

Low oxygen levels within the blood (pO2 and SaO2 combined)

49

Give four causes of tissue hypoxia

1. Anaemic hypoxia
2. Perfusional hypoxia
3. Toxic hypoxia
4. Hypoxaemic hypoxia

50

What causes anaemic hypoxia?

Lack of Hb

51

What causes perfusional hypoxia?

Poor CO

52

What causes toxic hypoxia?

Failure of release of O2 at tissue level

53

What causes hypoxaemic hypoxia?

Low pO2 and SaO2 - respiratory insufficiency

54

Name 4 buffers

1. Haemoglobin
2. Bicarbonate
3. Ammonium
4. Phosphate

55

Can overcompensation occur?

NO

56

Name three causes of respiratory acidosis with metabolic compensation

Chronic type 2 respiratory failure: COPD, DF, kyphoscoliosis

57

Name 3 causes of metabolic alkalosis with respiratory compensation?

Milk alkali syndrome
Vomiting
Severe hypokalaemia

58

Give 5 causes of metabolic acidosis with respiratory compensation?

Sepsis
DKA
Poisoning
Drugs
Lactate

59

What are general causes of respiratory alkalosis with metabolic compensation?

Chronic hyper-ventilatory states

60

What are 9 causes of high anion gap? (AMUDPILES)

A - alcohol (alcohol dissociates to become a weak acid)
M - methanol (causes blindness)
U - uraemia (failure to reabsorb HCO3 and excrete H+
D - DKA (ketones are dehydrogenated alcohols, and dissociate to acid)
P - paraquat (very nasty poison, universally lethal
I - infection (commonest, localised tissue hypoxia leads to...)
L - lactic acid (product of anaerobic respiration, and tissue necrosis)
E - erythlene gylcol (antifreeze)
S - salicylates (aspirin causes respiratory alkalosis, then metabolic acidosis

61

What can these 5 things occur as a result of? Addisons disease, high output fistulas, RTA I, II, IV, Acetazolamide therapy, diarrhoea?

Normal anion gap

62

Who were pink puffers traditionally though to be?

Emphysema patients

63

What to pink puffers react to hypoxaemia by doing?

Hyperventilating

64

Who were blue bloaters traditionally though to be?

Chronic bronchitis patients

65

What do blue bloaters not do?

React to hypoxia or hyperventilate

66

hi

hi

67

In acid base balance, what is being regulated?

Hydrogen ion concentration ([H+], pH)