Deck 29: Acid-Base Control and Acid-Base Disorders

Question 1

The base excess or base deficit is useful to the physician, because this value:

A)provides an indirect measure of the hemoglobin concentration in whole blood.
B)identifies the state of compensation of the acid-base imbalance.
C)permits estimation of the number of milliequivalents of acid or base that would be required to correct the pH to 7.4.
D)provides a direct measure of base available in the body, irrespective of the amount of acid present in the body.

Answer 1

permits estimation of the number of milliequivalents of acid or base that would be required to correct the pH to 7.4.

Question 2

The major physiological buffer is:

A)bicarbonate
B)hemoglobin
C)phosphate
D)protein

Answer 2

hemoglobin

Question 3

Calculate the pH of a blood sample, given a pKₐ = 6.1 and a bicarbonate-to-dissolved-carbon-dioxide ratio of 18:1.

A)6.10
B)7.36
C)7.47
D)Cannot be determined from the information provided

Answer 3

7.36

Question 4

A normal total CO₂, increased pCO₂, and decreased pH is most correctly classified as:

A)uncompensated metabolic acidosis
B)compensated metabolic acidosis
C)uncompensated respiratory acidosis
D)compensated respiratory acidosis

Question 5

An increased total CO₂, normal pCO₂, and increased pH is most correctly classified as:

A)uncompensated metabolic alkalosis
B)compensated metabolic alkalosis
C)uncompensated respiratory alkalosis
D)compensated respiratory alkalosis

Question 6

An increased total CO₂, increased pCO₂, and increased pH is most correctly classified as:

A)partially compensated metabolic acidosis
B)partially compensated metabolic alkalosis
C)partially compensated respiratory acidosis
D)partially compensated respiratory alkalosis

Question 7

Why is the bicarbonate buffer system chosen for the laboratory monitoring of physiological pH?

A)The bicarbonate buffering system has an immediate buffer response.
B)The bicarbonate buffering system has the greatest buffering capacity in the body.
C)The bicarbonate buffering system is the only buffer system located outside of cells.
D)The components of the bicarbonate buffer system are the easiest to measure.

Question 8

Given the following arterial blood-gas results, which choice best describes the expected base excess/deficit and total CO₂ results for the sample?
PH = 7.32
PCO₂ = 65 mm Hg
HCO₃ = 24 mEq/L

A)a base excess (above normal) and a normal total CO₂
B)a base deficit (below normal) and a normal total CO₂
C)a base excess (above normal) and a significantly decreased total CO₂
D)a base deficit (below normal) and a significantly increased total CO₂

Question 9

Calculate the bicarbonate concentration, given the following information.
PH = 7.10
PCO₂ = 78 mm Hg

A)19 mmol/L
B)21 mmol/L
C)24 mmol/L
D)26 mmol/L

Question 10

The base excess in a blood sample at a pH of 7.40, a pCO₂ of 40 mm Hg, a hemoglobin of 150 g/L, and a temperature of 37°C is equal to:

A)-2.5 mEq/L
B)0 mEq/L
C)1.2 mEq/L
D)2.5 mEq/L

Question 11

A decreased total CO₂, decreased pCO₂, and a normal pH is correctly classified as:
1)compensated metabolic acidosis
2)compensated metabolic alkalosis
3)compensated respiratory acidosis
4)compensated respiratory alkalosis

A)1, 4
B)2, 3
C)3 only
D)4 only

Question 12

A decreased total CO₂, decreased pCO₂, and decreased pH is most correctly classified as:

A)partially compensated metabolic acidosis
B)partially compensated metabolic alkalosis
C)partially compensated respiratory acidosis
D)partially compensated respiratory alkalosis

Question 13

Calculate the pH of a blood sample that has a total CO₂ of 26.1 mmol/L and a pCO₂ of 40.5 mm Hg.

A)7.31
B)7.39
C)7.47
D)7.52

Question 14

Which of the following is the normal reference interval for arterial pH?

A)7.31 - 7.41
B)7.33 - 7.43
C)7.35 - 7.45
D)7.45 - 7.55

Question 15

Which of the following normal reference intervals is incorrect for an arterial blood sample?

A)pH = 7.35 - 7.45
B)pCO₂ = 24 - 28 mmHg
C)HCO₃ = 22 - 26 mmol/L
D)TCO₂ = 23 - 27 mmol/L

Question 16

Given the following laboratory data, select the test(s) that would be useful in the identification of the cause of the acid-base imbalance?
PH = 7.25
PCO₂ = 25 mm Hg
Cl = 100 mEq/L
TCO₂ = 15 mEq/L
Na = 140 mEq/L
K = 7.4 mEq/L

A)serum or urine acetone
B)blood lactate
C)serum or urine salicylate
D)all of the above