PMHNP Certification Exam Review
(2026/2027) – 500+ Questions &
Answers for Psychiatric Mental Health
Nurse Practitioner LMR Exam Prep
(PDF)
Section 1: Patient Data Evaluation & ABG Interpretation
Question 1
A patient's ABG shows pH 7.48, PaCO₂ 30 mmHg, HCO₃⁻ 22 mEq/L. What is the
interpretation?
A: Respiratory acidosis
B: Respiratory alkalosis
C: Metabolic acidosis
D: Metabolic alkalosis
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 respiratory alkalosis (hyperventilation) .
Question 2
A patient's ABG shows pH 7.28, PaCO₂ 55 mmHg, HCO₃⁻ 25 mEq/L. What is the
interpretation?
,A: Acute respiratory acidosis
B: Chronic respiratory acidosis
C: Metabolic acidosis with respiratory compensation
D: Mixed acidosis
Rationale: Acute respiratory acidosis is characterized by decreased pH (<7.35), elevated
PaCO₂ (>45 mmHg), and normal or minimally elevated HCO₃⁻. Here, pH 7.28, PaCO₂ 55,
and normal HCO₃⁻ 25 indicate acute respiratory acidosis .
Question 3
A patient's ABG shows pH 7.35, PaCO₂ 50 mmHg, HCO₃⁻ 28 mEq/L. What is the
interpretation?
A: Acute respiratory acidosis
B: Chronic respiratory acidosis with compensation
C: Metabolic alkalosis
D: Normal ABGs
Rationale: Chronic respiratory acidosis is characterized by a low-normal pH, elevated
PaCO₂ (>45 mmHg), and elevated HCO₃⁻ (>26 mEq/L) indicating renal compensation.
Here, pH 7.35, PaCO₂ 50, and HCO₃⁻ 28 indicate chronic respiratory acidosis with
compensation .
Question 4
A patient's ABG shows pH 7.50, PaCO₂ 48 mmHg, HCO₃⁻ 36 mEq/L. What is the
interpretation?
A: Acute respiratory acidosis
B: Metabolic alkalosis with respiratory compensation
C: Respiratory alkalosis
D: Mixed acidosis
Rationale: Metabolic alkalosis is characterized by elevated pH (>7.45), elevated HCO₃⁻
(>26 mEq/L), and compensatory elevation of PaCO₂. Here, pH 7.50, HCO₃⁻ 36, and
PaCO₂ 48 indicate metabolic alkalosis with respiratory compensation .
,Question 5
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: Increase IV fluids
Rationale: This ABG shows acute on chronic respiratory acidosis (low pH, elevated
PaCO₂, elevated HCO₃⁻) with hypoxemia. NIPPV is the appropriate intervention to
support ventilation and improve gas exchange .
Question 6
What is needed to calculate alveolar oxygen tension (PAO₂)?
A: VD/VT and PAO₂
B: Barometric pressure and FiO₂
C: PetCO₂ and PaO₂
D: QS/QT and deadspace
Rationale: The alveolar gas equation requires barometric pressure (PB), FiO₂, and
PaCO₂. Barometric pressure and FiO₂ are both included in the formula: PAO₂ = (PB -
PH₂O) × FiO₂ - (PaCO₂ / RQ) .
Question 7
L/min/m² is the unit of measure for which of the following?
A: Systemic vascular resistance
B: Cardiac output
C: Cardiac index
D: Stroke volume
, Rationale: Cardiac index = Cardiac output / Body surface area. Normal cardiac index is
2.5-4.0 L/min/m². Cardiac output alone is measured in L/min .
Question 8
A patient's PFT shows reduced FVC, reduced TLC, and a normal FEV1/FVC ratio. What is
the interpretation?
A: Restrictive lung disease
B: Obstructive lung disease
C: Combined obstructive-restrictive lung disease
D: The test is invalid
Rationale: A restrictive defect is characterized by reduced FVC, reduced TLC, and a
normal FEV1/FVC ratio. This indicates the lungs are stiff and cannot fully expand .
Question 9
A patient with COPD on 2 L/min nasal cannula has ABG: pH 7.32, PaCO₂ 67 mmHg, PaO₂
62 mmHg. What is the interpretation?
A: Acute on chronic respiratory acidosis
B: Metabolic acidosis with compensation
C: Respiratory alkalosis
D: Normal ABGs
Rationale: The pH of 7.32 indicates acidosis. The PaCO₂ of 67 mmHg is significantly
elevated (normal 35-45), indicating respiratory acidosis. This is consistent with acute
exacerbation of chronic COPD .
Question 10
A patient's ABG shows pH 7.47, PaCO₂ 31 mmHg, and PaO₂ 55 mmHg on 60% O₂. What
is the P/F ratio?
(2026/2027) – 500+ Questions &
Answers for Psychiatric Mental Health
Nurse Practitioner LMR Exam Prep
(PDF)
Section 1: Patient Data Evaluation & ABG Interpretation
Question 1
A patient's ABG shows pH 7.48, PaCO₂ 30 mmHg, HCO₃⁻ 22 mEq/L. What is the
interpretation?
A: Respiratory acidosis
B: Respiratory alkalosis
C: Metabolic acidosis
D: Metabolic alkalosis
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 respiratory alkalosis (hyperventilation) .
Question 2
A patient's ABG shows pH 7.28, PaCO₂ 55 mmHg, HCO₃⁻ 25 mEq/L. What is the
interpretation?
,A: Acute respiratory acidosis
B: Chronic respiratory acidosis
C: Metabolic acidosis with respiratory compensation
D: Mixed acidosis
Rationale: Acute respiratory acidosis is characterized by decreased pH (<7.35), elevated
PaCO₂ (>45 mmHg), and normal or minimally elevated HCO₃⁻. Here, pH 7.28, PaCO₂ 55,
and normal HCO₃⁻ 25 indicate acute respiratory acidosis .
Question 3
A patient's ABG shows pH 7.35, PaCO₂ 50 mmHg, HCO₃⁻ 28 mEq/L. What is the
interpretation?
A: Acute respiratory acidosis
B: Chronic respiratory acidosis with compensation
C: Metabolic alkalosis
D: Normal ABGs
Rationale: Chronic respiratory acidosis is characterized by a low-normal pH, elevated
PaCO₂ (>45 mmHg), and elevated HCO₃⁻ (>26 mEq/L) indicating renal compensation.
Here, pH 7.35, PaCO₂ 50, and HCO₃⁻ 28 indicate chronic respiratory acidosis with
compensation .
Question 4
A patient's ABG shows pH 7.50, PaCO₂ 48 mmHg, HCO₃⁻ 36 mEq/L. What is the
interpretation?
A: Acute respiratory acidosis
B: Metabolic alkalosis with respiratory compensation
C: Respiratory alkalosis
D: Mixed acidosis
Rationale: Metabolic alkalosis is characterized by elevated pH (>7.45), elevated HCO₃⁻
(>26 mEq/L), and compensatory elevation of PaCO₂. Here, pH 7.50, HCO₃⁻ 36, and
PaCO₂ 48 indicate metabolic alkalosis with respiratory compensation .
,Question 5
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: Increase IV fluids
Rationale: This ABG shows acute on chronic respiratory acidosis (low pH, elevated
PaCO₂, elevated HCO₃⁻) with hypoxemia. NIPPV is the appropriate intervention to
support ventilation and improve gas exchange .
Question 6
What is needed to calculate alveolar oxygen tension (PAO₂)?
A: VD/VT and PAO₂
B: Barometric pressure and FiO₂
C: PetCO₂ and PaO₂
D: QS/QT and deadspace
Rationale: The alveolar gas equation requires barometric pressure (PB), FiO₂, and
PaCO₂. Barometric pressure and FiO₂ are both included in the formula: PAO₂ = (PB -
PH₂O) × FiO₂ - (PaCO₂ / RQ) .
Question 7
L/min/m² is the unit of measure for which of the following?
A: Systemic vascular resistance
B: Cardiac output
C: Cardiac index
D: Stroke volume
, Rationale: Cardiac index = Cardiac output / Body surface area. Normal cardiac index is
2.5-4.0 L/min/m². Cardiac output alone is measured in L/min .
Question 8
A patient's PFT shows reduced FVC, reduced TLC, and a normal FEV1/FVC ratio. What is
the interpretation?
A: Restrictive lung disease
B: Obstructive lung disease
C: Combined obstructive-restrictive lung disease
D: The test is invalid
Rationale: A restrictive defect is characterized by reduced FVC, reduced TLC, and a
normal FEV1/FVC ratio. This indicates the lungs are stiff and cannot fully expand .
Question 9
A patient with COPD on 2 L/min nasal cannula has ABG: pH 7.32, PaCO₂ 67 mmHg, PaO₂
62 mmHg. What is the interpretation?
A: Acute on chronic respiratory acidosis
B: Metabolic acidosis with compensation
C: Respiratory alkalosis
D: Normal ABGs
Rationale: The pH of 7.32 indicates acidosis. The PaCO₂ of 67 mmHg is significantly
elevated (normal 35-45), indicating respiratory acidosis. This is consistent with acute
exacerbation of chronic COPD .
Question 10
A patient's ABG shows pH 7.47, PaCO₂ 31 mmHg, and PaO₂ 55 mmHg on 60% O₂. What
is the P/F ratio?
