NBRC TMC Exam Review (2026) – 300+
Questions, Terms & Answers for
Respiratory Therapist TMC Board Exam
Prep Review Study Guide (PDF)
SECTION 1: PATIENT DATA EVALUATION (Domain I)
Question 1
A 68-year-old male with a history of COPD presents with increased shortness of breath. His ABG on room
air shows: pH 7.32, PaCO2 58 mmHg, PaO2 52 mmHg, HCO3 30 mEq/L. What is the most appropriate
interpretation?
A) Acute respiratory acidosis
B) Chronic respiratory acidosis with acute exacerbation
C) Metabolic alkalosis with respiratory compensation
D) Normal ABG
Correct Answer: B) Chronic respiratory acidosis with acute exacerbation
Rationale: The ABG shows respiratory acidosis (pH low, PaCO2 high) with metabolic compensation
(elevated HCO3). The HCO3 of 30 suggests chronic CO2 retention (renal compensation) with an acute
exacerbation causing further pH decline.
Question 2
A 72-year-old patient with COPD has the following ABG results: pH 7.36, PaCO2 64 mmHg, PaO2 58
mmHg, HCO3 35 mEq/L. What is the most appropriate interpretation?
A) Acute respiratory acidosis
B) Chronic respiratory acidosis
C) Partially compensated metabolic alkalosis
D) Normal ABG
Correct Answer: B) Chronic respiratory acidosis
Rationale: The pH is near normal despite significantly elevated PaCO2, and the HCO3 is elevated (renal
compensation). This pattern indicates chronic respiratory acidosis with full renal compensation. In acute
respiratory acidosis, the pH would be lower and HCO3 would be normal or only slightly elevated.
Question 3
,An intubated patient has an ABG showing: pH 7.28, PaCO2 48 mmHg, PaO2 72 mmHg, HCO3 22 mEq/L.
What ventilator adjustment is most appropriate?
A) Increase the respiratory rate
B) Decrease the tidal volume
C) Increase the FiO2
D) Add PEEP
Correct Answer: A) Increase the respiratory rate
Rationale: The patient has respiratory acidosis (low pH, elevated PaCO2). Increasing the respiratory rate
will increase minute ventilation, helping to blow off CO2. The PaO2 of 72 mmHg is acceptable, so FiO2
and PEEP do not need adjustment.
Question 4
A 65-year-old patient with asthma is on a 40% Venturi mask. ABG results show: pH 7.50, PaCO2 30
mmHg, PaO2 80 mmHg, HCO3 24 mEq/L. What is the most appropriate interpretation?
A) Respiratory acidosis
B) Respiratory alkalosis
C) Metabolic acidosis
D) Normal ABG
Correct Answer: B) Respiratory alkalosis
Rationale: The pH is elevated (alkalemia), PaCO2 is low (30 mmHg), and HCO3 is normal. This is
consistent with respiratory alkalosis, which can occur in asthma due to hyperventilation. The
oxygenation is adequate on 40% oxygen.
Question 5
A 74-year-old patient is receiving mechanical ventilation. ABG shows: pH 7.22, PaCO2 55 mmHg, PaO2 68
mmHg, HCO3 22 mEq/L. What is the most appropriate ventilator adjustment?
A) Increase tidal volume
B) Decrease respiratory rate
C) Decrease FiO2
D) Add PEEP
Correct Answer: A) Increase tidal volume
Rationale: The patient has acute respiratory acidosis (low pH, elevated PaCO2). Increasing tidal volume
or respiratory rate will increase alveolar ventilation and help normalize CO2. PaO2 of 68 is acceptable on
current FiO2, so no FiO2 change is needed.
,Question 6
A 60-year-old patient with COPD on 2 L/min nasal cannula has the following ABG: pH 7.36, PaCO2 60
mmHg, PaO2 65 mmHg, HCO3 34 mEq/L. What is the most appropriate interpretation?
A) Acute respiratory failure
B) Chronic respiratory failure with compensation
C) Metabolic alkalosis
D) Hypoxemic respiratory failure
Correct Answer: B) Chronic respiratory failure with compensation
Rationale: The pH is near normal despite significantly elevated PaCO2, and the HCO3 is elevated
(compensation). This pattern is consistent with chronic respiratory failure due to COPD. The PaO2 of 65
indicates mild hypoxemia. Acute respiratory failure would show a much lower pH.
Question 7
A patient on mechanical ventilation has the following ABG: pH 7.48, PaCO2 32 mmHg, PaO2 90 mmHg,
HCO3 24 mEq/L. What is the appropriate action?
A) Increase respiratory rate
B) Decrease respiratory rate
C) Increase tidal volume
D) Decrease FiO2
Correct Answer: B) Decrease respiratory rate
Rationale: The ABG shows respiratory alkalosis (elevated pH, low PaCO2) due to excessive ventilation.
Decreasing the respiratory rate will reduce alveolar ventilation and allow CO2 to rise toward normal.
Question 8
A 66-year-old patient with diabetes and renal failure presents with ABG results: pH 7.30, PaCO2 30
mmHg, PaO2 88 mmHg, HCO3 14 mEq/L. What is the most appropriate interpretation?
A) Respiratory acidosis
B) Metabolic acidosis with respiratory compensation
C) Metabolic alkalosis
D) Respiratory alkalosis
Correct Answer: B) Metabolic acidosis with respiratory compensation
Rationale: The low pH and low HCO3 indicate metabolic acidosis. The low PaCO2 represents respiratory
compensation (hyperventilation). This is consistent with diabetic ketoacidosis or renal failure-induced
metabolic acidosis.
, Question 9
A 70-year-old patient with heart failure is on 60% FiO2 via non-rebreather. ABG shows: pH 7.32, PaCO2
48 mmHg, PaO2 55 mmHg, HCO3 24 mEq/L. What is the most appropriate interpretation?
A) Acute respiratory acidosis with hypoxemia
B) Metabolic acidosis
C) Chronic respiratory acidosis
D) Normal oxygenation
Correct Answer: A) Acute respiratory acidosis with hypoxemia
Rationale: The low pH and elevated PaCO2 indicate acute respiratory acidosis. The PaO2 of 55 despite
60% FiO2 indicates significant hypoxemia. This patient may require intubation and mechanical
ventilation.
Question 10
A patient has the following ABG results: pH 7.20, PaCO2 60 mmHg, PaO2 50 mmHg, HCO3 22 mEq/L.
What is the most appropriate interpretation?
A) Partially compensated metabolic acidosis
B) Uncompensated respiratory acidosis
C) Fully compensated respiratory acidosis
D) Normal ABG
Correct Answer: B) Uncompensated respiratory acidosis
Rationale: The pH is low (acidemia) with elevated PaCO2 and normal HCO3. This pattern is consistent
with acute, uncompensated respiratory acidosis. The lack of HCO3 elevation indicates that renal
compensation has not yet occurred (requires 24-48 hours).
Question 11
A patient on mechanical ventilation has an ABG showing: pH 7.38, PaCO2 45 mmHg, PaO2 85 mmHg,
HCO3 26 mEq/L. What is the most appropriate interpretation?
A) Normal ABG with adequate ventilation
B) Respiratory acidosis
C) Metabolic acidosis
D) Hypoxemia
Correct Answer: A) Normal ABG with adequate ventilation
Rationale: All values are within normal limits: pH 7.35-7.45, PaCO2 35-45, PaO2 80-100, HCO3 22-26.
This indicates adequate ventilation and oxygenation.
Questions, Terms & Answers for
Respiratory Therapist TMC Board Exam
Prep Review Study Guide (PDF)
SECTION 1: PATIENT DATA EVALUATION (Domain I)
Question 1
A 68-year-old male with a history of COPD presents with increased shortness of breath. His ABG on room
air shows: pH 7.32, PaCO2 58 mmHg, PaO2 52 mmHg, HCO3 30 mEq/L. What is the most appropriate
interpretation?
A) Acute respiratory acidosis
B) Chronic respiratory acidosis with acute exacerbation
C) Metabolic alkalosis with respiratory compensation
D) Normal ABG
Correct Answer: B) Chronic respiratory acidosis with acute exacerbation
Rationale: The ABG shows respiratory acidosis (pH low, PaCO2 high) with metabolic compensation
(elevated HCO3). The HCO3 of 30 suggests chronic CO2 retention (renal compensation) with an acute
exacerbation causing further pH decline.
Question 2
A 72-year-old patient with COPD has the following ABG results: pH 7.36, PaCO2 64 mmHg, PaO2 58
mmHg, HCO3 35 mEq/L. What is the most appropriate interpretation?
A) Acute respiratory acidosis
B) Chronic respiratory acidosis
C) Partially compensated metabolic alkalosis
D) Normal ABG
Correct Answer: B) Chronic respiratory acidosis
Rationale: The pH is near normal despite significantly elevated PaCO2, and the HCO3 is elevated (renal
compensation). This pattern indicates chronic respiratory acidosis with full renal compensation. In acute
respiratory acidosis, the pH would be lower and HCO3 would be normal or only slightly elevated.
Question 3
,An intubated patient has an ABG showing: pH 7.28, PaCO2 48 mmHg, PaO2 72 mmHg, HCO3 22 mEq/L.
What ventilator adjustment is most appropriate?
A) Increase the respiratory rate
B) Decrease the tidal volume
C) Increase the FiO2
D) Add PEEP
Correct Answer: A) Increase the respiratory rate
Rationale: The patient has respiratory acidosis (low pH, elevated PaCO2). Increasing the respiratory rate
will increase minute ventilation, helping to blow off CO2. The PaO2 of 72 mmHg is acceptable, so FiO2
and PEEP do not need adjustment.
Question 4
A 65-year-old patient with asthma is on a 40% Venturi mask. ABG results show: pH 7.50, PaCO2 30
mmHg, PaO2 80 mmHg, HCO3 24 mEq/L. What is the most appropriate interpretation?
A) Respiratory acidosis
B) Respiratory alkalosis
C) Metabolic acidosis
D) Normal ABG
Correct Answer: B) Respiratory alkalosis
Rationale: The pH is elevated (alkalemia), PaCO2 is low (30 mmHg), and HCO3 is normal. This is
consistent with respiratory alkalosis, which can occur in asthma due to hyperventilation. The
oxygenation is adequate on 40% oxygen.
Question 5
A 74-year-old patient is receiving mechanical ventilation. ABG shows: pH 7.22, PaCO2 55 mmHg, PaO2 68
mmHg, HCO3 22 mEq/L. What is the most appropriate ventilator adjustment?
A) Increase tidal volume
B) Decrease respiratory rate
C) Decrease FiO2
D) Add PEEP
Correct Answer: A) Increase tidal volume
Rationale: The patient has acute respiratory acidosis (low pH, elevated PaCO2). Increasing tidal volume
or respiratory rate will increase alveolar ventilation and help normalize CO2. PaO2 of 68 is acceptable on
current FiO2, so no FiO2 change is needed.
,Question 6
A 60-year-old patient with COPD on 2 L/min nasal cannula has the following ABG: pH 7.36, PaCO2 60
mmHg, PaO2 65 mmHg, HCO3 34 mEq/L. What is the most appropriate interpretation?
A) Acute respiratory failure
B) Chronic respiratory failure with compensation
C) Metabolic alkalosis
D) Hypoxemic respiratory failure
Correct Answer: B) Chronic respiratory failure with compensation
Rationale: The pH is near normal despite significantly elevated PaCO2, and the HCO3 is elevated
(compensation). This pattern is consistent with chronic respiratory failure due to COPD. The PaO2 of 65
indicates mild hypoxemia. Acute respiratory failure would show a much lower pH.
Question 7
A patient on mechanical ventilation has the following ABG: pH 7.48, PaCO2 32 mmHg, PaO2 90 mmHg,
HCO3 24 mEq/L. What is the appropriate action?
A) Increase respiratory rate
B) Decrease respiratory rate
C) Increase tidal volume
D) Decrease FiO2
Correct Answer: B) Decrease respiratory rate
Rationale: The ABG shows respiratory alkalosis (elevated pH, low PaCO2) due to excessive ventilation.
Decreasing the respiratory rate will reduce alveolar ventilation and allow CO2 to rise toward normal.
Question 8
A 66-year-old patient with diabetes and renal failure presents with ABG results: pH 7.30, PaCO2 30
mmHg, PaO2 88 mmHg, HCO3 14 mEq/L. What is the most appropriate interpretation?
A) Respiratory acidosis
B) Metabolic acidosis with respiratory compensation
C) Metabolic alkalosis
D) Respiratory alkalosis
Correct Answer: B) Metabolic acidosis with respiratory compensation
Rationale: The low pH and low HCO3 indicate metabolic acidosis. The low PaCO2 represents respiratory
compensation (hyperventilation). This is consistent with diabetic ketoacidosis or renal failure-induced
metabolic acidosis.
, Question 9
A 70-year-old patient with heart failure is on 60% FiO2 via non-rebreather. ABG shows: pH 7.32, PaCO2
48 mmHg, PaO2 55 mmHg, HCO3 24 mEq/L. What is the most appropriate interpretation?
A) Acute respiratory acidosis with hypoxemia
B) Metabolic acidosis
C) Chronic respiratory acidosis
D) Normal oxygenation
Correct Answer: A) Acute respiratory acidosis with hypoxemia
Rationale: The low pH and elevated PaCO2 indicate acute respiratory acidosis. The PaO2 of 55 despite
60% FiO2 indicates significant hypoxemia. This patient may require intubation and mechanical
ventilation.
Question 10
A patient has the following ABG results: pH 7.20, PaCO2 60 mmHg, PaO2 50 mmHg, HCO3 22 mEq/L.
What is the most appropriate interpretation?
A) Partially compensated metabolic acidosis
B) Uncompensated respiratory acidosis
C) Fully compensated respiratory acidosis
D) Normal ABG
Correct Answer: B) Uncompensated respiratory acidosis
Rationale: The pH is low (acidemia) with elevated PaCO2 and normal HCO3. This pattern is consistent
with acute, uncompensated respiratory acidosis. The lack of HCO3 elevation indicates that renal
compensation has not yet occurred (requires 24-48 hours).
Question 11
A patient on mechanical ventilation has an ABG showing: pH 7.38, PaCO2 45 mmHg, PaO2 85 mmHg,
HCO3 26 mEq/L. What is the most appropriate interpretation?
A) Normal ABG with adequate ventilation
B) Respiratory acidosis
C) Metabolic acidosis
D) Hypoxemia
Correct Answer: A) Normal ABG with adequate ventilation
Rationale: All values are within normal limits: pH 7.35-7.45, PaCO2 35-45, PaO2 80-100, HCO3 22-26.
This indicates adequate ventilation and oxygenation.
