Introduction to Acid-base balance

Question 1

Acid

Answer 1

A substance that can donate H+ (and has a high concentration of H+)

Question 2

Base

Answer 2

A substance that can accept a H+ (low H+ concentration)

Question 3

As H+ increases

Answer 3

pH decreases by a log of 10

Question 4

As H+ decreases

Answer 4

pH increases by a log of 10

Question 5

What is the normal blood pH

Answer 5

7.35-7.45

Question 6

Acidemia

Answer 6

Increase in H+ means a low pH (

Question 7

Alkalemia

Answer 7

Decrease in H+, means a high pH (>7.40)

Question 8

Acidosis

Answer 8

Process which increases plasma H+

Question 9

Alkalosis

Answer 9

Process which decrease plasma H+

Question 10

How does the body regulate (balance) acids and bases

Answer 10

1. Chemical buffer system
2. Respiratory buffer systems
3. Liver oxidation of strong acids
4. Renal mechanisms
   (Goes in this order)

Question 11

Chemical buffer system

Answer 11

1. phosphate (IC)
2. protein (hemoglobin, amino acids, plasma proteins)
3. HCO3 (carbonic acid becomes bicarb)

Question 12

Respiratory buffer system

Answer 12

Retain or blow off CO2 depending on whether it is an acidosis or alkalosis problem

Question 13

What part of the brain controls the respiratory buffer system

Answer 13

Brainstem (acts within 1-3mins)

Question 14

What happens to respirations when there is a rise in H+ (metabolic acidosis)

Answer 14

Deep, rapid breathing, expels CO2 which causes H+ to be reduced

Question 15

What happens to respirations when there is a decrease in H+ (metabolic alkalosis)

Answer 15

Slower, shallow breathing, expels less CO2, which causes H+ to be increased

Question 16

Kidney role in H+ maintenance

Answer 16

ONLY the kidneys can get rid of non-volatile acids (lactic, uric, phosphoric) via H+, HCO3 excretion or reusing of the H+ (NH4)

Question 17

What is the ultimate acid-base regulatory organ

Answer 17

Kidney

Question 18

Most important renal mechanism for regulating HCO3

Answer 18

1. Reabsorbs HCO3 and generates new HCO3

2. Excretes HCO3

Question 19

What does reabsorption of HCO3 defend agains

Answer 19

Acidosis

Question 20

What does excretion of HCO3 defend against

Answer 20

Alkalosis

Question 21

ABG

Answer 21

Arterial blood gas. Measures pH, pCO2, pO2 Calculates HCO3

Question 22

pH=

Answer 22

HCO3/pCO2

Question 23

What is the usefulness of the ABG

Answer 23

Determining if a patient has metabolic/respiratory acidosis or alkalosis

Question 24

What is the normal pCO2

Answer 24

38-42

Question 25

What is the normal HCO3

Answer 25

24 (22-26)

Question 26

Anion gap

Answer 26

The difference in measured cations (+) and measured anions (-). Can measure in serum, plasma, or urine

Question 27

Normal AG

Answer 27

12 (+/-2)

Question 28

Actual AG equation

Answer 28

Na+ - (Cl- + HCO3-)... Cations minus anions

Question 29

What is the diagnosis if you have a high AG

Answer 29

metabolic acidosis

Question 30

1st step in acid-base disorders

Answer 30

Consider clinical setting (anticipate the disorder)

Question 31

2nd step in acid-base disorders

Answer 31

Is the patient academic or alkalemic

Question 32

3rd step in acid-base disorders

Answer 32

Is the process metabolic or respiratory

Question 33

4th step in acid-base disorders

Answer 33

If metabolic acidosis, is there an anion gap or not

Question 34

5th step in acid-base disorders

Answer 34

Is compensation appropriate (use formulas)

Question 35

6th step in acid-base disorders

Answer 35

Is there more than one disorder present, use the change in formulas

Question 36

If it is a metabolic problem

Answer 36

The lungs will try and compensate

Question 37

If it is a respiratory problem

Answer 37

the kidneys will try and compensate

Question 38

What 2 things do you look for in order to determine if it is metabolic

Answer 38

HCO3 and pCO2 lab values should go in the same direction

Question 39

Respiratory alkalosis

Answer 39

Hyperventilation, causes decrease in pCO2, which increases pH

Question 40

Signs of respiratory alkalosis

Answer 40

Dizziness, light headed, confusion (pts on ventilators)

Question 41

Lab findings of respiratory alkalosis

Answer 41

``` pH = increase pCO2 = decrease HCO3 = decrease (renal compensation) ```

Question 42

Respiratory acidosis

Answer 42

Hypoventilation, causes an increase in pCO2, which decreases pH

Question 43

Signs/causes of respiratory acidosis

Answer 43

Upper airway obstruction, SOB, headache, blurred vision

Question 44

Lab finding of respiratory acidosis

Answer 44

pH = decrease pCO2 = increase HCO3 = increase (renal compensation

Question 45

Metabolic alkalosis

Answer 45

Too much OH-, very little H+

Question 46

Signs/causes of metabolic alkalosis

Answer 46

Loss of H+, or retention of bicarbonate. Slow, shallow breathing

Question 47

Lab finding of metabolic alkalosis

Answer 47

pH = increase pCO2 = increase HCO3 = increase (respiratory compensation)

Question 48

Metabolic acidosis

Answer 48

Too much H+, very little OH-

Question 49

Signs/causes of metabolic acidosis

Answer 49

Kidney cannot clear the H+ or too much H+ generation. Deep, rapid breathing

Question 50

Lab finding of metabolic acidosis

Answer 50

``` pH= decrease pCO2 = decrease HCO3 = decrease ```

Question 51

Mixed/compensatory acid/base

Answer 51

More than one acid-base disorder occurring simultaneously. You will see pCO2 and HCO3 in opposite directions