Week # 10 Acid-Base Balance/Respiratory Chemistries & Arterial Blood Gas Analysis

Question 1

What is an acid?

Answer 1

a molecule that donates protons (H+)

Question 2

What is a base?

Answer 2

a molecule that accepts protons (H+)

Question 3

What is a buffer?

Answer 3

any substance that can reversibly bind hydrogen ions

Question 4

Name a few buffers.

Answer 4

in plasma: bicarb, hemoglobin, proteins

in urine: phosphate, ammonia

Question 5

When the renal buffer system compensates for changes in pH, how long does it take to notice the compensation?

Answer 5

appreciable response in 12-24 hours, but max response takes up to 3-5 days

Question 6

What is the definition of anion gap?

Answer 6

the difference between the major measured cations and major measured anions

(Na+ + K+) - (Cl- + HCO3-)
normal range = 7-14 mEq/L

Question 7

What does pKa represent?

Answer 7

the pH at which a drug is 50% ionized

Question 8

What is another name for non-anion gap acidosis?

Answer 8

hyperchloremic acidosis

Question 9

The weaker the acid, the ______ the base.

Answer 9

stronger

Question 10

The weaker the base, the ______ the acid.

Answer 10

stronger

Question 11

Identify this ABG:

pH=7.21, PaCO2=40, HCO3=15.6

Answer 11

metabolic acidosis

Question 12

Identify this ABG:

pH=7.34, PaCO2=28, HCO3=19

Answer 12

compensated metabolic acidosis

Question 13

Identify this ABG:

pH=7.51, PaCO2=39, HCO3=31

Answer 13

metabolic alkalosis

Question 14

Identify this ABG:

pH=7.1, PaCO2=55, HCO3=22

Answer 14

respiratory acidosis

Question 15

Identify this ABG:

pH=7.33, PaCO2=56, HCO3=30

Answer 15

compensated respiratory acidosis

Question 16

Identify this ABG:

pH=7.57, PaCO2=24, HCO3=23

Answer 16

respiratory alkalosis

Question 17

What are the order and components analyzed in blood gas analysis? (i got this from the study guide, I apologize for the length)

Answer 17

1. Examine arterial pH: Is acidemia or alkalemia present?
2. Examine PaCO2: Is the change in PaCO2 consistent with a respiratory component?
3. If the change in PaCO2 does not explain the change in arterial pH, does the change in [HCO3–] indicate a metabolic component?
4. Make a tentative diagnosis (see Table 30–1).
5. Compare the change in [HCO3–] with the change in PaCO2. Does a compensatory response exist (Table 30–7)?
6. If the compensatory response is more or less than expected, by definition a mixed acid–base disorder exists.
7. Calculate the plasma anion gap in the case of metabolic acidosis.
8. Measure urinary chloride concentration in the case of metabolic alkalosis.

Question 18

Which will equilibrate in solution: weak acids or strong acids?

Answer 18

weak acids

Question 19

Which will go to completion in a solution: weak acids or strong acids?

Answer 19

strong acids

Question 20

Which side of this equation is the conjugate base and which side is the conjugate acid?

LA + H+ —–> LAH+

Answer 20

LA + H+ ——-> LAH+
(conjugate (conjugate
base) acid)

Question 21

The pH, HCO3-, and H+ could be changed by what 3 things?

Answer 21

1. PaCO2
2. total amount of weak acids (ATOT)
3. strong ion difference (SID)
   (Na+) - (Cl- + HCO3-)

Question 22

Minute ventilation is mediated by central chemoreceptors in the brain stem. These changes are made in response to a change in ___ in the _____.

Answer 22

H+ in the cerebral spinal fluid

Question 23

Are the kidneys able to eliminate acids from the body?

Answer 23

yes…. how nice.