,NURS 4581 Exam 1 | Nursing of Adults with Complex Needs
(2026) Q&A | University of Texas at Arlington
1. Which of the following best describes the primary function of the renal system in acid-
base balance?
A) Excreting carbon dioxide through the lungs
B) Secreting free hydrogen ions and conserving bicarbonate
C) Producing carbonic acid to buffer the blood
D) Regulating oxygen saturation in the arterial blood
Correct Answer: Secreting free hydrogen ions and conserving bicarbonate
Rationale: The renal system regulates acid-base balance by secreting free hydrogen ions
and conserving bicarbonate in the extracellular fluid. The respiratory system regulates
carbonic acid through carbon dioxide elimination. The primary buffer system is the
bicarbonate-carbonic acid buffer system, not the renal system directly.
2. A client has an arterial blood gas result of pH 7.32, PaCO2 50 mm Hg, and HCO3 26
mEq/L. How should the nurse interpret this result?
A) Respiratory alkalosis with metabolic compensation
B) Metabolic acidosis with respiratory compensation
C) Respiratory acidosis with mild hypoxemia
D) Metabolic alkalosis with respiratory compensation
Correct Answer: Respiratory acidosis with mild hypoxemia
Rationale: A pH below 7.35 indicates acidosis. An elevated PaCO2 above 45 mm Hg
indicates the respiratory system is the cause, making this respiratory acidosis. The HCO3 is
,within normal limits (22-28 mEq/L), so there is no metabolic compensation. If PaO2 is 60
mm Hg, this also indicates mild hypoxemia.
3. When collecting an arterial blood gas sample from the radial artery, which assessment
should the nurse perform prior to the puncture?
A) Capillary refill test
B) Allen test
C) Romberg test
D) Trendelenburg test
Correct Answer: Allen test
Rationale: The Allen test is performed before radial artery puncture to assess collateral
circulation. The nurse has the client clench their fist while applying pressure to both the
radial and ulnar arteries, then releases pressure from the ulnar artery and observes for
return of color. If color returns within 7 seconds, the test is negative and the radial artery
can be safely used.
4. What is the most important nursing action after obtaining an arterial blood gas sample?
A) Apply a warm compress to the puncture site
B) Place the syringe on ice and analyze within 10-15 minutes
C) Have the client flex the wrist repeatedly
D) Administer oxygen via nasal cannula
Correct Answer: Place the syringe on ice and analyze within 10-15 minutes
Rationale: After obtaining an ABG sample, the syringe should be placed on ice and
analyzed within 10-15 minutes to prevent changes in the blood gas values. Delays in
, analysis can lead to inaccurate results due to ongoing cellular metabolism. Applying
pressure to the puncture site is also important to prevent hematoma.
5. A client with COPD has a pH of 7.32, PaCO2 of 46 mm Hg, and HCO3 of 28 mEq/L. How
should the nurse interpret this ABG?
A) Respiratory acidosis, partially compensated
B) Respiratory alkalosis, partially compensated
C) Metabolic acidosis, partially compensated
D) Metabolic alkalosis, partially compensated
Correct Answer: Respiratory acidosis, partially compensated
Rationale: The pH is below 7.35, indicating acidosis. The PaCO2 is elevated, indicating a
respiratory cause. The HCO3 is elevated above normal, indicating the kidneys are retaining
bicarbonate to compensate. Since the pH is still abnormal, this is partially compensated
respiratory acidosis.
6. Which of the following would the nurse expect to see in a client with metabolic acidosis?
A) pH 7.48, CO2 45, HCO3 28
B) pH 7.32, CO2 32, HCO3 16
C) pH 7.38, CO2 40, HCO3 26
D) pH 7.25, CO2 65, HCO3 26
Correct Answer: pH 7.32, CO2 32, HCO3 16
Rationale: Metabolic acidosis is characterized by a pH below 7.35 and a bicarbonate level
below 22 mEq/L. The respiratory system compensates by hyperventilating to blow off
carbon dioxide, so the CO2 would be low. The combination of low pH, low HCO3, and low
CO2 indicates metabolic acidosis with respiratory compensation.
(2026) Q&A | University of Texas at Arlington
1. Which of the following best describes the primary function of the renal system in acid-
base balance?
A) Excreting carbon dioxide through the lungs
B) Secreting free hydrogen ions and conserving bicarbonate
C) Producing carbonic acid to buffer the blood
D) Regulating oxygen saturation in the arterial blood
Correct Answer: Secreting free hydrogen ions and conserving bicarbonate
Rationale: The renal system regulates acid-base balance by secreting free hydrogen ions
and conserving bicarbonate in the extracellular fluid. The respiratory system regulates
carbonic acid through carbon dioxide elimination. The primary buffer system is the
bicarbonate-carbonic acid buffer system, not the renal system directly.
2. A client has an arterial blood gas result of pH 7.32, PaCO2 50 mm Hg, and HCO3 26
mEq/L. How should the nurse interpret this result?
A) Respiratory alkalosis with metabolic compensation
B) Metabolic acidosis with respiratory compensation
C) Respiratory acidosis with mild hypoxemia
D) Metabolic alkalosis with respiratory compensation
Correct Answer: Respiratory acidosis with mild hypoxemia
Rationale: A pH below 7.35 indicates acidosis. An elevated PaCO2 above 45 mm Hg
indicates the respiratory system is the cause, making this respiratory acidosis. The HCO3 is
,within normal limits (22-28 mEq/L), so there is no metabolic compensation. If PaO2 is 60
mm Hg, this also indicates mild hypoxemia.
3. When collecting an arterial blood gas sample from the radial artery, which assessment
should the nurse perform prior to the puncture?
A) Capillary refill test
B) Allen test
C) Romberg test
D) Trendelenburg test
Correct Answer: Allen test
Rationale: The Allen test is performed before radial artery puncture to assess collateral
circulation. The nurse has the client clench their fist while applying pressure to both the
radial and ulnar arteries, then releases pressure from the ulnar artery and observes for
return of color. If color returns within 7 seconds, the test is negative and the radial artery
can be safely used.
4. What is the most important nursing action after obtaining an arterial blood gas sample?
A) Apply a warm compress to the puncture site
B) Place the syringe on ice and analyze within 10-15 minutes
C) Have the client flex the wrist repeatedly
D) Administer oxygen via nasal cannula
Correct Answer: Place the syringe on ice and analyze within 10-15 minutes
Rationale: After obtaining an ABG sample, the syringe should be placed on ice and
analyzed within 10-15 minutes to prevent changes in the blood gas values. Delays in
, analysis can lead to inaccurate results due to ongoing cellular metabolism. Applying
pressure to the puncture site is also important to prevent hematoma.
5. A client with COPD has a pH of 7.32, PaCO2 of 46 mm Hg, and HCO3 of 28 mEq/L. How
should the nurse interpret this ABG?
A) Respiratory acidosis, partially compensated
B) Respiratory alkalosis, partially compensated
C) Metabolic acidosis, partially compensated
D) Metabolic alkalosis, partially compensated
Correct Answer: Respiratory acidosis, partially compensated
Rationale: The pH is below 7.35, indicating acidosis. The PaCO2 is elevated, indicating a
respiratory cause. The HCO3 is elevated above normal, indicating the kidneys are retaining
bicarbonate to compensate. Since the pH is still abnormal, this is partially compensated
respiratory acidosis.
6. Which of the following would the nurse expect to see in a client with metabolic acidosis?
A) pH 7.48, CO2 45, HCO3 28
B) pH 7.32, CO2 32, HCO3 16
C) pH 7.38, CO2 40, HCO3 26
D) pH 7.25, CO2 65, HCO3 26
Correct Answer: pH 7.32, CO2 32, HCO3 16
Rationale: Metabolic acidosis is characterized by a pH below 7.35 and a bicarbonate level
below 22 mEq/L. The respiratory system compensates by hyperventilating to blow off
carbon dioxide, so the CO2 would be low. The combination of low pH, low HCO3, and low
CO2 indicates metabolic acidosis with respiratory compensation.
