Exam 4 - Electrolytes 3

Question 1

Hypoventilation

Answer 1

increases blood CO2 levels (person will become acidotic)

Question 2

Hyperventilation

Answer 2

decreases blood CO2 levels (person will become alkalotic)

Question 3

Increase CO2 and decreased pH

Answer 3

stimulate pulmonary ventilation

Question 4

Increase pH

Answer 4

inhibits pulmonary ventilation

Question 5

Renal control of pH

Answer 5

• most powerful “buffer” system (but slow response)
• allows for reabsorption of HCO3- into ECF
• renal tubules secrete H+ into tubular fluid then excrete it in urine

Question 6

H+ secretion

Answer 6

• rate of H+ secretion INCREASES as body fluid pH DECREASES (as H+ increases) or as ALDOSTERONE LEVELS INCREASE
• secretion of H+ inhibited when urine pH falls below 4.5

Question 7

Tubular secretion of H+ continues only w/…?

Answer 7

only w/ a concentration gradient of H+ between tubule cells and tubular fluid
- if H+ concentration increases in tubular fluid (lowering pH to 4.5), secretion of H+ stops

Question 8

Buffers in tubular fluid

Answer 8

• bicarbonate system
• phosphate system
• ammonia

Question 9

Acidosis

Answer 9

H+ diffuses into cells and drives K+ out, elevating K+ concentration in ECF(hyperkalemia)

Question 10

Effect of acidosis

Answer 10

H+ buffered by protein in ICF thus causing membrane HYPERPOLARIZATION
- nerve and muscle cells are hard to stimulate (CNS depression may lead to death)

Question 11

Alkalosis

Answer 11

H+ diffuses out of cells and K+ diffuses in

Question 12

Effect of alkalosis

Answer 12

• membranes become DEPOLARIZED

- nerves overstimulate muscles causing spasms, tetany, convulsions, respiratory paralysis

Question 13

Respiratory acidosis and example

Answer 13

rate of alveolar ventilation balls behind CO2 production

EX: emphysema

Question 14

Respiratory alkalosis and example

Answer 14

CO2 eliminated faster than it is produced

EX: hyperventilation

Question 15

Metabolic acidosis

Answer 15

• increased production of organic acids (lactic acid, ketones)
• ingestion of acidic drugs (aspirin)
• loss of base (chronic diarrhea, laxative overuse)

Question 16

Metabolic alkalosis

Answer 16

• overuse of bicarbonates (antacids)

- loss of acid (chronic vomiting)

Question 17

Process of diagnosing an acid-base imbalance

Answer 17

1. Note whether the pH is high or low relative to the normal range (this tells you whether you have acidosis or alkalosis)
2. Decide which value of pCO2 or HCO3- could cause the abnormality (this tells you whether you have a respiratory or metabolic problem)
3. Look at the NON-CAUSATIVE VALUE and determine if it is appropriately compensating for the problem (this tells you whether r not you have more than one problem going on)

Question 18

Normal pH value

Answer 18

7.40

Question 19

Anything below 7.40

Answer 19

acidosis

Question 20

Anything above 7.40

Answer 20

alkalosis

Question 21

Normal pCO2 value

Answer 21

40

Question 22

pCO2 above 40

Answer 22

• tends toward acidosis
• causes low pH
• neutralizes high pH

Question 23

pCO2 below 40

Answer 23

• tends toward alkalosis
• causes high pH
• neutralizes low pH

Question 24

Normal HCO3- (bicarbonate) level

Answer 24

24

Question 25

High pH, high pCO2

Answer 25

metabolic alkalosis

Question 26

High pH, low pCO2

Answer 26

respiratory alkalosis

Question 27

Low pH, high pCO2

Answer 27

respiratory acidosis (HCO3- will be high because it's moving in the right direction to try to compensate for the acidosis)

Question 28

Low pH, low pCO2, low HCO3-

Answer 28

metabolic acidosis (decreased HCO3- leads to acidosis)

Question 29

Metabolic causes are in the same direction as...

Answer 29

pH increase pH, increase bicarb decrease pH, decrease bicarb

Question 30

Compensation

Answer 30

when both pCO2 and HCO3- rise or fall together to maintain NEARLY NORMAL pH (between 7.35 and 7.45)

Question 31

Partial (inadequate) compensation

Answer 31

occurs when pCO2 and HCO3- levels rise or fall together but the pH REMAINS PRETTY ABNORMAL

Question 32

What does partial (inadequate) compensation tell you?

Answer 32

- tells you that you have more than one problem on your hands

Question 33

EX: pH = 7.44 pCO2 = 30 HCO3- = 18

Answer 33

- alkalosis - respiratory - complete compensation

Question 34

Anion Gap =

Answer 34

Na - (Cl + HCO3-)

Question 35

non-anion gap acidosis

Answer 35

< or = 12

Question 36

positive anion gap acidosis

Answer 36

>12

Question 37

MULEPAK (possibilities that lead to a positive anion gap acidosis)

Answer 37

- Methanol - Uremia - Lactic acid - Ethylene glycol - Paraldehyde - Aspirin - Ketoacidosis