Acid-Base

Question 1

How is pH measured?

Answer 1

ISE

Question 2

PCO2 is in equilibrium with what?

Answer 2

H2CO3 (carbonic acid)

Question 3

T or F: PO2 is the measure of O2 attached to albumin.

Answer 3

F- it’s diffused in plasma, not attached to alb

Question 4

Normal pH is ___ - ____.

Answer 4

7.35-7.45

Question 5

What is the normal HCO3/H2CO3 ratio?

Answer 5

20:1

Question 6

What does a decreased HCO3/H2CO3 ratio suggest?

Answer 6

acidosis

Question 7

What does an increased HCO3/H2CO3 ratio suggest?

Answer 7

alkalosis

Question 8

What are the 2 major buffer systems?

Answer 8

bicarb and Hg

Question 9

What are the 2 minor buffer systems?

Answer 9

inorganic phosphate and plasma proteins

Question 10

What does the body do to keep the HCO3/H2CO3 ratio at 20:1 when there’s a change in HCO3?

Answer 10

changes respiratory rate to alter PCO2

Question 11

What does the body do to keep the HCO3/H2CO3 ratio at 20:1 when there’s a change in H2CO3 (which is pretty much the same thing as PCO2)?

Answer 11

changes metabolic state to alter HCO3

Question 12

CO2 retention due to hypoventilation or severe impairment of gas exchange causes ____.

Answer 12

respiratory acidosis

Question 13

Bicarbonate excess causes ____.

Answer 13

metabolic alkalosis

Question 14

Gastric parietal cells combine ___ and ___ to make carbonic acid which dissociates into ___ & ____.

Answer 14

Gastric parietal cells combine CO2 and H2O to make carbonic acid which dissociates into H & HCO3.

Question 15

What are 3 causes of abnormal neurologic control of breathing which lead to resp acidosis?

Answer 15

anesthesia
sedation
head trauma

Question 16

What are 7 causes of muscular or mechanical failure which lead to resp acidosis?

Answer 16

pneumothorax
pleural effusion 
ivermectin tox
coonhound paralysis
m. gravis
neutotoxins (botulism)
paralytic drugs

Question 17

What are 3 causes of upper airway obstruction which lead to resp acidosis?

Answer 17

calf diphtheria
tracheal collapse
laryngeal edema/constriction

Question 18

What are 3 causes of lung abnormalities which lead to resp acidosis?

Answer 18

severe pneumonia
severe pulmonary edema
COPD

Question 19

What are 5 causes of altered respiratory control which lead to resp alkalosis?

Answer 19

convulsions
fever
fear/anxiety
heat
hepatic encephalopathy

Question 20

What are 5 causes of hypoxemial which lead to resp alkalosis?

Answer 20

hypotension
pulmonary vascular shunts
pulmonary fibrosis
pneumonia
pulmonary edema

Question 21

CO2 loss due to hyperventilation causes ____.

Answer 21

resp alkalosis

Question 22

Is mild pneumonia more likely to cause resp acidosis or resp alkalosis?

Answer 22

resp alkalosis (b/c it’s impairing O2 exchange so breathing harder to get more O2, but CO2 exchange isn’t affected and end up blowing off too much CO2–> alkalosis)

Question 23

How is SO2 determined?

Answer 23

analyzer measures pO2 and calculates SO2 (% Hg saturated with O2) based on Hg-O2 dissociation curve

Question 24

Why is base excess calculated?

Answer 24

to account for the combined bicarb and Hg buffering capacity of the blood

Question 25

What does a + base excess indicate?

Answer 25

alkalosis

Question 26

What does a - base excess indicate?

Answer 26

acidosis (magnitude of HCO3 deficit)

Question 27

What 4 things do you need to measure the BE?

Answer 27

measured Hg standard HCO3 PCO2 body temp

Question 28

How is the normal BE different in horses/cows and dogs/cats?

Answer 28

usually >0 in horses and cows and

Question 29

The SaO2 measured from cooximetry is proportional to what on the blood gas?

Answer 29

PO2

Question 30

Most of the TCO2 in the body is ____.

Answer 30

HCO3

Question 31

How does an underfilled tube affect TCO2 measurements?

Answer 31

It can result in falsely decreased TCO2

Question 32

In secretory acidosis, loss of NaHCO3 rich fluids causes net acidification because of ____ retention.

Answer 32

HCl

Question 33

What are 4 causes of sectional acidosis?

Answer 33

Choke Secretional diarrhea Obstruction RTA

Question 34

Pattern for secretional acidosis: HCO/TCO2- Cl- AG-

Answer 34

HCO/TCO2- decr Cl- normal or incr AG- normal

Question 35

Pattern for titrational acidosis: HCO/TCO2- Cl- AG-

Answer 35

HCO/TCO2- decr Cl- normal AG- incr

Question 36

What are 3 causes of loss of gastric/abomasal HCl leading to met alk?

Answer 36

vomiting/tubing horses abomasal obstruction (physical, functional, stasis) prox jejunitis-ileitis in horses

Question 37

Pattern for metabolic alkalosis: HCO/TCO2- Cl- AG-

Answer 37

HCO/TCO2- incr Cl- decr AG- N or slighly incr

Question 38

What 3 things do you have to have to get paradoxical aciduria?

Answer 38

hypovolemia, hypoCl, tbK depletion

Question 39

How does paradoxical aciduria happen?

Answer 39

kidneys resorb Na because trying to keep water in--> Cl usually comes with but deficient so HCO3 resorbed w/Na instead; Na can also exchange w/K or H to be resorbed but K is low so exchanges w/ H

Question 40

How is hypoK associated with met alk?

Answer 40

f

Question 41

How can liver failure cause met alk? (uncommon cause)

Answer 41

BE builds up (NH3 and amines)

Question 42

How can the sheep blowfly cause met alk?

Answer 42

it makes a lot of NH3 (base excess)