Walden University NRNP 6566 Final Exam (pdf) | 2026/2027 | Q&A |
Advanced Care of Adults Acute I
**1. A 62-year-old male is brought to the emergency department with acute
respiratory distress. His arterial blood gas (ABG) on room air shows: pH 7.28,
PaCO2 55 mmHg, PaO2 68 mmHg, HCO3 24 mEq/L. Which of the following
best describes this ABG interpretation?**
A) Uncompensated respiratory acidosis
B) Partially compensated respiratory acidosis
C) Uncompensated metabolic acidosis
D) Compensated respiratory alkalosis
**Correct Answer: A**
**Rationale:** The pH is low (7.28 < 7.35), indicating acidosis. The PaCO2 is
elevated (55 > 45 mmHg), indicating a respiratory cause. The HCO3 is
normal (24 mEq/L), indicating no metabolic compensation has occurred yet.
This is uncompensated respiratory acidosis.
---
**2. A 58-year-old female with a history of COPD is admitted with an acute
exacerbation. Her ABG on 2 L nasal cannula shows: pH 7.32, PaCO2 65
mmHg, PaO2 72 mmHg, HCO3 32 mEq/L. What is the correct interpretation
of this ABG?**
A) Uncompensated respiratory acidosis
B) Partially compensated respiratory acidosis
C) Fully compensated respiratory acidosis
D) Uncompensated metabolic acidosis
,**Correct Answer: B**
**Rationale:** The pH is low (7.32), indicating acidosis. The PaCO2 is
elevated (65 mmHg), indicating a respiratory cause. The HCO3 is elevated
(32 mEq/L), indicating the kidneys have begun to compensate by retaining
bicarbonate. Since the pH is still abnormal, this is **partially compensated**
respiratory acidosis.
---
**3. A 45-year-old male is intubated and receiving mechanical ventilation.
His ABG shows: pH 7.48, PaCO2 30 mmHg, PaO2 95 mmHg, HCO3 22 mEq/L.
What is the most appropriate ventilator adjustment?**
A) Increase tidal volume
B) Decrease respiratory rate
C) Increase PEEP
D) Increase FiO2
**Correct Answer: B**
**Rationale:** The ABG shows respiratory alkalosis (pH > 7.45, PaCO2 < 35
mmHg) due to excessive ventilation. Decreasing the respiratory rate will
allow the PaCO2 to rise and correct the alkalosis.
---
**4. Which of the following is the formula for calculating the alveolar-arterial
(A-a) gradient?**
,A) A-a gradient = PaO2 - PaCO2
B) A-a gradient = PAO2 - PaO2
C) A-a gradient = PAO2 + PaO2
D) A-a gradient = PaCO2 - PaO2
**Correct Answer: B**
**Rationale:** The A-a gradient is the difference between the alveolar
oxygen tension (PAO2) and the arterial oxygen tension (PaO2). It is
calculated as PAO2 - PaO2. An elevated A-a gradient indicates impaired gas
exchange, such as in V/Q mismatch, shunting, or diffusion impairment.
---
**5. The alveolar gas equation is used to calculate PAO2. Which of the
following is the correct formula?**
A) PAO2 = FiO2 × (Patm - PH2O) - (PaCO2 / R)
B) PAO2 = FiO2 × (Patm + PH2O) - (PaCO2 × R)
C) PAO2 = FiO2 × (Patm - PH2O) - (PaCO2 × R)
D) PAO2 = FiO2 × (Patm - PH2O) + (PaCO2 / R)
**Correct Answer: A**
**Rationale:** The alveolar gas equation is PAO2 = FiO2 × (Patm - PH2O) -
(PaCO2 / R), where Patm is atmospheric pressure (760 mmHg at sea level),
PH2O is the partial pressure of water (47 mmHg at 37°C), and R is the
respiratory quotient (approximately 0.8).
, ---
**6. A 70-year-old male is breathing room air (FiO2 = 0.21) at sea level. His
PaCO2 is 40 mmHg, and his PaO2 is 75 mmHg. What is his approximate A-a
gradient? (Assume R = 0.8)**
A) 5 mmHg
B) 15 mmHg
C) 25 mmHg
D) 35 mmHg
**Correct Answer: B**
**Rationale:** First, calculate PAO2 = 0.21 × (760 - 47) - (.8) = 0.21 ×
713 - 50 = 149.7 - 50 = 99.7 mmHg. Then A-a gradient = PAO2 - PaO2 =
99.7 - 75 = 24.7 mmHg. However, the normal A-a gradient varies with age.
Using the formula: normal gradient = 2.5 + 0.21 × age = 2.5 + 0.21 × 70 =
2.5 + 14.7 = 17.2 mmHg. The calculated A-a gradient of 24.7 mmHg is
elevated, indicating a gas exchange abnormality.
---
**7. A patient with a V/Q mismatch is likely to have which of the following
ABG findings?**
A) Normal A-a gradient with hypoxemia
B) Elevated A-a gradient with hypoxemia
C) Normal A-a gradient with hypercapnia
Advanced Care of Adults Acute I
**1. A 62-year-old male is brought to the emergency department with acute
respiratory distress. His arterial blood gas (ABG) on room air shows: pH 7.28,
PaCO2 55 mmHg, PaO2 68 mmHg, HCO3 24 mEq/L. Which of the following
best describes this ABG interpretation?**
A) Uncompensated respiratory acidosis
B) Partially compensated respiratory acidosis
C) Uncompensated metabolic acidosis
D) Compensated respiratory alkalosis
**Correct Answer: A**
**Rationale:** The pH is low (7.28 < 7.35), indicating acidosis. The PaCO2 is
elevated (55 > 45 mmHg), indicating a respiratory cause. The HCO3 is
normal (24 mEq/L), indicating no metabolic compensation has occurred yet.
This is uncompensated respiratory acidosis.
---
**2. A 58-year-old female with a history of COPD is admitted with an acute
exacerbation. Her ABG on 2 L nasal cannula shows: pH 7.32, PaCO2 65
mmHg, PaO2 72 mmHg, HCO3 32 mEq/L. What is the correct interpretation
of this ABG?**
A) Uncompensated respiratory acidosis
B) Partially compensated respiratory acidosis
C) Fully compensated respiratory acidosis
D) Uncompensated metabolic acidosis
,**Correct Answer: B**
**Rationale:** The pH is low (7.32), indicating acidosis. The PaCO2 is
elevated (65 mmHg), indicating a respiratory cause. The HCO3 is elevated
(32 mEq/L), indicating the kidneys have begun to compensate by retaining
bicarbonate. Since the pH is still abnormal, this is **partially compensated**
respiratory acidosis.
---
**3. A 45-year-old male is intubated and receiving mechanical ventilation.
His ABG shows: pH 7.48, PaCO2 30 mmHg, PaO2 95 mmHg, HCO3 22 mEq/L.
What is the most appropriate ventilator adjustment?**
A) Increase tidal volume
B) Decrease respiratory rate
C) Increase PEEP
D) Increase FiO2
**Correct Answer: B**
**Rationale:** The ABG shows respiratory alkalosis (pH > 7.45, PaCO2 < 35
mmHg) due to excessive ventilation. Decreasing the respiratory rate will
allow the PaCO2 to rise and correct the alkalosis.
---
**4. Which of the following is the formula for calculating the alveolar-arterial
(A-a) gradient?**
,A) A-a gradient = PaO2 - PaCO2
B) A-a gradient = PAO2 - PaO2
C) A-a gradient = PAO2 + PaO2
D) A-a gradient = PaCO2 - PaO2
**Correct Answer: B**
**Rationale:** The A-a gradient is the difference between the alveolar
oxygen tension (PAO2) and the arterial oxygen tension (PaO2). It is
calculated as PAO2 - PaO2. An elevated A-a gradient indicates impaired gas
exchange, such as in V/Q mismatch, shunting, or diffusion impairment.
---
**5. The alveolar gas equation is used to calculate PAO2. Which of the
following is the correct formula?**
A) PAO2 = FiO2 × (Patm - PH2O) - (PaCO2 / R)
B) PAO2 = FiO2 × (Patm + PH2O) - (PaCO2 × R)
C) PAO2 = FiO2 × (Patm - PH2O) - (PaCO2 × R)
D) PAO2 = FiO2 × (Patm - PH2O) + (PaCO2 / R)
**Correct Answer: A**
**Rationale:** The alveolar gas equation is PAO2 = FiO2 × (Patm - PH2O) -
(PaCO2 / R), where Patm is atmospheric pressure (760 mmHg at sea level),
PH2O is the partial pressure of water (47 mmHg at 37°C), and R is the
respiratory quotient (approximately 0.8).
, ---
**6. A 70-year-old male is breathing room air (FiO2 = 0.21) at sea level. His
PaCO2 is 40 mmHg, and his PaO2 is 75 mmHg. What is his approximate A-a
gradient? (Assume R = 0.8)**
A) 5 mmHg
B) 15 mmHg
C) 25 mmHg
D) 35 mmHg
**Correct Answer: B**
**Rationale:** First, calculate PAO2 = 0.21 × (760 - 47) - (.8) = 0.21 ×
713 - 50 = 149.7 - 50 = 99.7 mmHg. Then A-a gradient = PAO2 - PaO2 =
99.7 - 75 = 24.7 mmHg. However, the normal A-a gradient varies with age.
Using the formula: normal gradient = 2.5 + 0.21 × age = 2.5 + 0.21 × 70 =
2.5 + 14.7 = 17.2 mmHg. The calculated A-a gradient of 24.7 mmHg is
elevated, indicating a gas exchange abnormality.
---
**7. A patient with a V/Q mismatch is likely to have which of the following
ABG findings?**
A) Normal A-a gradient with hypoxemia
B) Elevated A-a gradient with hypoxemia
C) Normal A-a gradient with hypercapnia
