NBRC TMC/CRT/RRT Version 3 Exam:
Questions & Answers | Complete A+
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SECTION 1: PATIENT ASSESSMENT & ABG INTERPRETATION
Question 1
A 68-year-old patient with COPD is receiving oxygen via nasal cannula at 2 L/min. ABG
results show pH 7.32, PaCO₂ 68 mmHg, PaO₂ 55 mmHg, HCO₃⁻ 34 mEq/L. What is the
most appropriate intervention?
A) Increase oxygen to 4 L/min via nasal cannula
B) Initiate noninvasive positive pressure ventilation (NIPPV)
C) Administer sodium bicarbonate
D) Decrease oxygen to 1 L/min
Correct Answer: B
Rationale: The ABG shows chronic respiratory acidosis (pH 7.32, PaCO₂ 68, HCO₃⁻ 34)
with inadequate ventilation. NIPPV is indicated to support ventilation and reduce PaCO₂
without the risks of invasive mechanical ventilation. Increasing oxygen alone would not
address the underlying hypoventilation; sodium bicarbonate is not indicated for
respiratory acidosis; decreasing oxygen could worsen hypoxemia.
Question 2
A patient's ABG shows pH 7.48, PaCO₂ 30 mmHg, HCO₃⁻ 22 mEq/L. This is consistent
with:
A) Respiratory acidosis
B) Respiratory alkalosis
C) Metabolic acidosis
D) Metabolic alkalosis
Correct Answer: B
,Rationale: Respiratory alkalosis is characterized by elevated pH (>7.45) and decreased
PaCO₂ (<35 mmHg) with normal HCO₃⁻. This ABG shows pH 7.48, PaCO₂ 30, and normal
HCO₃⁻ 22, indicating primary hyperventilation.
Question 3
A patient's ABG shows pH 7.28, PaCO₂ 55 mmHg, HCO₃⁻ 25 mEq/L. This is consistent
with:
A) Acute respiratory acidosis
B) Chronic respiratory acidosis
C) Metabolic acidosis with respiratory compensation
D) Mixed acidosis
Correct Answer: A
Rationale: Acute respiratory acidosis is characterized by decreased pH (<7.35), elevated
PaCO₂ (>45 mmHg), and normal or minimally elevated HCO₃⁻. The HCO₃⁻ of 25 indicates
minimal renal compensation, consistent with acute rather than chronic respiratory
acidosis.
Question 4
A patient's ABG shows pH 7.50, PaCO₂ 48 mmHg, HCO₃⁻ 36 mEq/L. This is consistent
with:
A) Acute respiratory acidosis
B) Metabolic alkalosis with respiratory compensation
C) Respiratory alkalosis with metabolic compensation
D) Mixed alkalosis
Correct Answer: B
Rationale: Metabolic alkalosis is characterized by elevated pH (>7.45) and elevated
HCO₃⁻ (>26 mEq/L) with compensatory respiratory acidosis (elevated PaCO₂). The ABG
shows pH 7.50, HCO₃⁻ 36, and PaCO₂ 48, indicating metabolic alkalosis with
hypoventilation as compensation.
,Question 5
A patient's ABG shows pH 7.25, PaCO₂ 30 mmHg, HCO₃⁻ 12 mEq/L. This is consistent
with:
A) Respiratory acidosis with metabolic compensation
B) Metabolic acidosis with respiratory compensation
C) Mixed acidosis
D) Respiratory alkalosis with metabolic compensation
Correct Answer: B
Rationale: Metabolic acidosis is characterized by decreased pH (<7.35) and decreased
HCO₃⁻ (<22 mEq/L) with compensatory respiratory alkalosis (decreased PaCO₂). The ABG
shows pH 7.25, HCO₃⁻ 12, and PaCO₂ 30, indicating metabolic acidosis with respiratory
compensation.
Question 6
A patient's ABG shows pH 7.40, PaCO₂ 40 mmHg, HCO₃⁻ 24 mEq/L. This is:
A) Normal
B) Respiratory acidosis
C) Metabolic acidosis
D) Respiratory alkalosis
Correct Answer: A
Rationale: Normal ABG values are pH 7.35–7.45, PaCO₂ 35–45 mmHg, and HCO₃⁻ 22–26
mEq/L. This ABG falls within all normal parameters.
Question 7
Which of the following is the most reliable indicator of adequate oxygenation in a
patient receiving mechanical ventilation?
A) SpO₂ of 92%
B) PaO₂/FiO₂ ratio
C) PaO₂ of 80 mmHg
D) SaO₂ of 95%
, Correct Answer: B
Rationale: The PaO₂/FiO₂ (P/F) ratio is the most reliable indicator of oxygenation status
because it accounts for both the partial pressure of oxygen and the fraction of inspired
oxygen. A P/F ratio <300 indicates acute lung injury; <200 indicates ARDS.
Question 8
A patient has a PaO₂ of 50 mmHg on FiO₂ 0.40. The P/F ratio is:
A) 100
B) 125
C) 150
D) 200
Correct Answer: B
Rationale: P/F ratio = PaO₂ / FiO₂ = .40 = 125. A P/F ratio <200 indicates ARDS;
values between 200-300 indicate acute lung injury.
Question 9
Which of the following blood gas values is most consistent with metabolic alkalosis?
A) pH 7.50, PaCO₂ 48 mmHg, HCO₃⁻ 36 mEq/L
B) pH 7.30, PaCO₂ 50 mmHg, HCO₃⁻ 24 mEq/L
C) pH 7.45, PaCO₂ 30 mmHg, HCO₃⁻ 20 mEq/L
D) pH 7.35, PaCO₂ 40 mmHg, HCO₃⁻ 22 mEq/L
Correct Answer: A
Rationale: Metabolic alkalosis is characterized by pH >7.45, HCO₃⁻ >26 mEq/L, and
compensatory PaCO₂ elevation. Option A shows elevated pH, elevated HCO₃⁻, and
appropriate respiratory compensation.
Question 10
The normal A-a gradient for a young healthy adult on room air is approximately:
Questions & Answers | Complete A+
Guide | 100% Guaranteed Success
SECTION 1: PATIENT ASSESSMENT & ABG INTERPRETATION
Question 1
A 68-year-old patient with COPD is receiving oxygen via nasal cannula at 2 L/min. ABG
results show pH 7.32, PaCO₂ 68 mmHg, PaO₂ 55 mmHg, HCO₃⁻ 34 mEq/L. What is the
most appropriate intervention?
A) Increase oxygen to 4 L/min via nasal cannula
B) Initiate noninvasive positive pressure ventilation (NIPPV)
C) Administer sodium bicarbonate
D) Decrease oxygen to 1 L/min
Correct Answer: B
Rationale: The ABG shows chronic respiratory acidosis (pH 7.32, PaCO₂ 68, HCO₃⁻ 34)
with inadequate ventilation. NIPPV is indicated to support ventilation and reduce PaCO₂
without the risks of invasive mechanical ventilation. Increasing oxygen alone would not
address the underlying hypoventilation; sodium bicarbonate is not indicated for
respiratory acidosis; decreasing oxygen could worsen hypoxemia.
Question 2
A patient's ABG shows pH 7.48, PaCO₂ 30 mmHg, HCO₃⁻ 22 mEq/L. This is consistent
with:
A) Respiratory acidosis
B) Respiratory alkalosis
C) Metabolic acidosis
D) Metabolic alkalosis
Correct Answer: B
,Rationale: Respiratory alkalosis is characterized by elevated pH (>7.45) and decreased
PaCO₂ (<35 mmHg) with normal HCO₃⁻. This ABG shows pH 7.48, PaCO₂ 30, and normal
HCO₃⁻ 22, indicating primary hyperventilation.
Question 3
A patient's ABG shows pH 7.28, PaCO₂ 55 mmHg, HCO₃⁻ 25 mEq/L. This is consistent
with:
A) Acute respiratory acidosis
B) Chronic respiratory acidosis
C) Metabolic acidosis with respiratory compensation
D) Mixed acidosis
Correct Answer: A
Rationale: Acute respiratory acidosis is characterized by decreased pH (<7.35), elevated
PaCO₂ (>45 mmHg), and normal or minimally elevated HCO₃⁻. The HCO₃⁻ of 25 indicates
minimal renal compensation, consistent with acute rather than chronic respiratory
acidosis.
Question 4
A patient's ABG shows pH 7.50, PaCO₂ 48 mmHg, HCO₃⁻ 36 mEq/L. This is consistent
with:
A) Acute respiratory acidosis
B) Metabolic alkalosis with respiratory compensation
C) Respiratory alkalosis with metabolic compensation
D) Mixed alkalosis
Correct Answer: B
Rationale: Metabolic alkalosis is characterized by elevated pH (>7.45) and elevated
HCO₃⁻ (>26 mEq/L) with compensatory respiratory acidosis (elevated PaCO₂). The ABG
shows pH 7.50, HCO₃⁻ 36, and PaCO₂ 48, indicating metabolic alkalosis with
hypoventilation as compensation.
,Question 5
A patient's ABG shows pH 7.25, PaCO₂ 30 mmHg, HCO₃⁻ 12 mEq/L. This is consistent
with:
A) Respiratory acidosis with metabolic compensation
B) Metabolic acidosis with respiratory compensation
C) Mixed acidosis
D) Respiratory alkalosis with metabolic compensation
Correct Answer: B
Rationale: Metabolic acidosis is characterized by decreased pH (<7.35) and decreased
HCO₃⁻ (<22 mEq/L) with compensatory respiratory alkalosis (decreased PaCO₂). The ABG
shows pH 7.25, HCO₃⁻ 12, and PaCO₂ 30, indicating metabolic acidosis with respiratory
compensation.
Question 6
A patient's ABG shows pH 7.40, PaCO₂ 40 mmHg, HCO₃⁻ 24 mEq/L. This is:
A) Normal
B) Respiratory acidosis
C) Metabolic acidosis
D) Respiratory alkalosis
Correct Answer: A
Rationale: Normal ABG values are pH 7.35–7.45, PaCO₂ 35–45 mmHg, and HCO₃⁻ 22–26
mEq/L. This ABG falls within all normal parameters.
Question 7
Which of the following is the most reliable indicator of adequate oxygenation in a
patient receiving mechanical ventilation?
A) SpO₂ of 92%
B) PaO₂/FiO₂ ratio
C) PaO₂ of 80 mmHg
D) SaO₂ of 95%
, Correct Answer: B
Rationale: The PaO₂/FiO₂ (P/F) ratio is the most reliable indicator of oxygenation status
because it accounts for both the partial pressure of oxygen and the fraction of inspired
oxygen. A P/F ratio <300 indicates acute lung injury; <200 indicates ARDS.
Question 8
A patient has a PaO₂ of 50 mmHg on FiO₂ 0.40. The P/F ratio is:
A) 100
B) 125
C) 150
D) 200
Correct Answer: B
Rationale: P/F ratio = PaO₂ / FiO₂ = .40 = 125. A P/F ratio <200 indicates ARDS;
values between 200-300 indicate acute lung injury.
Question 9
Which of the following blood gas values is most consistent with metabolic alkalosis?
A) pH 7.50, PaCO₂ 48 mmHg, HCO₃⁻ 36 mEq/L
B) pH 7.30, PaCO₂ 50 mmHg, HCO₃⁻ 24 mEq/L
C) pH 7.45, PaCO₂ 30 mmHg, HCO₃⁻ 20 mEq/L
D) pH 7.35, PaCO₂ 40 mmHg, HCO₃⁻ 22 mEq/L
Correct Answer: A
Rationale: Metabolic alkalosis is characterized by pH >7.45, HCO₃⁻ >26 mEq/L, and
compensatory PaCO₂ elevation. Option A shows elevated pH, elevated HCO₃⁻, and
appropriate respiratory compensation.
Question 10
The normal A-a gradient for a young healthy adult on room air is approximately:
