NURS 4581 Exam 1 | NURS 4581 Nursing of Adults with
Complex Needs | Actual Q&A with Rationale (NURS 4581
Exam 1) | UT Arlington
Critical Care Exam 1 Acid-Base Disturbances &
Interventions
Section 1: Acid-Base Balance – Roles of Lungs, Kidneys, and
Buffers
(12 questions)
1. Which system is the fastest acting regulator of acid-base balance?
A. Lungs
B. Kidneys
C. Chemical buffers
D. Endocrine system
Answer: C
Rationale: Chemical buffers respond within seconds to neutralize acids or bases. The
lungs respond in minutes, kidneys take 2-3 days.
2. How do chemical buffers maintain acid-base balance?
A. By increasing ventilation
B. By excreting hydrogen ions in urine
C. By converting strong acids into weaker ones or binding acids to neutralize them
D. By retaining bicarbonate
Answer: C
Rationale: Buffers act immediately to convert strong acids into weaker acids or bind
hydrogen ions to prevent pH change.
3. The renal system compensates for acidosis by:
A. Excreting bicarbonate and retaining hydrogen ions
B. Generating additional bicarbonate and excreting excess hydrogen ions
C. Increasing respiratory rate
D. Retaining carbon dioxide
,Answer: B
Rationale: The kidneys can generate new bicarbonate and excrete H⁺ to compensate
for acidosis, though this takes 2–3 days.
4. The respiratory system responds to acidosis within:
A. Seconds
B. Minutes (reaches maximum response in hours)
C. 24 hours
D. 2–3 days
Answer: B
Rationale: The lungs adjust ventilation within minutes to change CO₂ levels; maximum
compensation occurs within hours.
5. If a patient retains CO₂ (hypercapnia), the appropriate respiratory compensation
is:
A. Hypoventilation
B. Hyperventilation to "blow off" CO₂
C. No change
D. Apnea
Answer: B
Rationale: When CO₂ is high, the lungs hyperventilate to eliminate excess CO₂ and
reduce acidosis.
6. If a patient has low CO₂ (hypocapnia), the appropriate respiratory compensation
is:
A. Hyperventilation
B. Hypoventilation to retain CO₂
C. No change
D. Cheyne-Stokes respirations
Answer: B
Rationale: Low CO₂ (alkalosis) triggers hypoventilation to retain CO₂ and correct the
alkalosis.
7. Acidosis is caused by:
A. An increase in carbonic acid or a decrease in bicarbonate
, B. A decrease in carbonic acid or an increase in bicarbonate
C. Hyperventilation
D. Excess antacids
Answer: A
Rationale: Acidosis results from excess acid (respiratory: ↑CO₂) or loss of base
(metabolic: ↓HCO₃⁻).
8. Alkalosis is caused by:
A. An increase in carbonic acid or decrease in bicarbonate
B. A decrease in carbonic acid or an increase in bicarbonate
C. Renal failure
D. Diabetic ketoacidosis
Answer: B
Rationale: Alkalosis results from loss of acid (respiratory: ↓CO₂) or gain of base
(metabolic: ↑HCO₃⁻).
9. The primary regulator of acid-base balance is:
A. Lungs
B. Kidneys
C. Chemical buffers
D. Liver
Answer: C
Rationale: Buffers are the first line of defense and act fastest, though they have limited
capacity.
10. How long does it take for the kidneys to fully compensate for an acid-base
disturbance?
A. Minutes
B. Hours
C. 2–3 days
D. 1 week
Answer: C
Rationale: Renal compensation begins within hours but requires 2–3 days to reach
maximum effect.
Complex Needs | Actual Q&A with Rationale (NURS 4581
Exam 1) | UT Arlington
Critical Care Exam 1 Acid-Base Disturbances &
Interventions
Section 1: Acid-Base Balance – Roles of Lungs, Kidneys, and
Buffers
(12 questions)
1. Which system is the fastest acting regulator of acid-base balance?
A. Lungs
B. Kidneys
C. Chemical buffers
D. Endocrine system
Answer: C
Rationale: Chemical buffers respond within seconds to neutralize acids or bases. The
lungs respond in minutes, kidneys take 2-3 days.
2. How do chemical buffers maintain acid-base balance?
A. By increasing ventilation
B. By excreting hydrogen ions in urine
C. By converting strong acids into weaker ones or binding acids to neutralize them
D. By retaining bicarbonate
Answer: C
Rationale: Buffers act immediately to convert strong acids into weaker acids or bind
hydrogen ions to prevent pH change.
3. The renal system compensates for acidosis by:
A. Excreting bicarbonate and retaining hydrogen ions
B. Generating additional bicarbonate and excreting excess hydrogen ions
C. Increasing respiratory rate
D. Retaining carbon dioxide
,Answer: B
Rationale: The kidneys can generate new bicarbonate and excrete H⁺ to compensate
for acidosis, though this takes 2–3 days.
4. The respiratory system responds to acidosis within:
A. Seconds
B. Minutes (reaches maximum response in hours)
C. 24 hours
D. 2–3 days
Answer: B
Rationale: The lungs adjust ventilation within minutes to change CO₂ levels; maximum
compensation occurs within hours.
5. If a patient retains CO₂ (hypercapnia), the appropriate respiratory compensation
is:
A. Hypoventilation
B. Hyperventilation to "blow off" CO₂
C. No change
D. Apnea
Answer: B
Rationale: When CO₂ is high, the lungs hyperventilate to eliminate excess CO₂ and
reduce acidosis.
6. If a patient has low CO₂ (hypocapnia), the appropriate respiratory compensation
is:
A. Hyperventilation
B. Hypoventilation to retain CO₂
C. No change
D. Cheyne-Stokes respirations
Answer: B
Rationale: Low CO₂ (alkalosis) triggers hypoventilation to retain CO₂ and correct the
alkalosis.
7. Acidosis is caused by:
A. An increase in carbonic acid or a decrease in bicarbonate
, B. A decrease in carbonic acid or an increase in bicarbonate
C. Hyperventilation
D. Excess antacids
Answer: A
Rationale: Acidosis results from excess acid (respiratory: ↑CO₂) or loss of base
(metabolic: ↓HCO₃⁻).
8. Alkalosis is caused by:
A. An increase in carbonic acid or decrease in bicarbonate
B. A decrease in carbonic acid or an increase in bicarbonate
C. Renal failure
D. Diabetic ketoacidosis
Answer: B
Rationale: Alkalosis results from loss of acid (respiratory: ↓CO₂) or gain of base
(metabolic: ↑HCO₃⁻).
9. The primary regulator of acid-base balance is:
A. Lungs
B. Kidneys
C. Chemical buffers
D. Liver
Answer: C
Rationale: Buffers are the first line of defense and act fastest, though they have limited
capacity.
10. How long does it take for the kidneys to fully compensate for an acid-base
disturbance?
A. Minutes
B. Hours
C. 2–3 days
D. 1 week
Answer: C
Rationale: Renal compensation begins within hours but requires 2–3 days to reach
maximum effect.
