NBRC TMC Certification Exam Questions and Verified
Answers with Rationale | Latest Edition 2026/2027
Question 1
A patient with severe acute respiratory distress syndrome is being
mechanically ventilated with a tidal volume of 4 mL/kg of predicted
body weight and a respiratory rate of 28 breaths/min. Arterial blood gas
results show pH 7.31, PaCO2 52 mm Hg, PaO2 62 mm Hg, and HCO3
26 mEq/L. Which of the following ventilator adjustments should the
respiratory therapist recommend first?
A. Increase the tidal volume to 8 mL/kg
B. Increase the respiratory rate to 34 breaths/min
C. Add or increase positive end-expiratory pressure
D. Switch to pressure control ventilation immediately
Correct Answer: C
Rationale: The patient is exhibiting refractory hypoxemia and is
managed with a lung-protective ventilation strategy using low tidal
volumes. In acute respiratory distress syndrome, increasing positive end-
expiratory pressure helps recruit collapsed alveoli, improve functional
residual capacity, and enhance oxygenation without exposing the lungs
to excessive stretch. Increasing tidal volume can cause volutrauma, and
a higher respiratory rate alone will not resolve the underlying
oxygenation deficit.
Question 2
During a pre-assessment check of a mechanical ventilator in the
intensive care unit, the respiratory therapist performs a circuit leak test
,and notes a significant difference between the set tidal volume and the
exhaled tidal volume. Which of the following components should be
inspected first?
A. The humidifier water level chamber
B. The expiratory valve and circuit connections
C. The internal oxygen blender sensor module
D. The main power supply backup battery pack
Correct Answer: B
Rationale: A discrepancy between delivered and exhaled tidal volumes
during a circuit check most commonly indicates a leak within the patient
circuit or around the expiratory valve assembly. Inspecting the tubing
connections, water traps, and the integrity of the expiratory valve
membrane is the most direct troubleshooting step to ensure accurate
volume delivery before patient connection.
Question 3
A 68 year old male with a history of chronic obstructive pulmonary
disease presents to the emergency department with acute shortness of
breath and lethargy. Arterial blood gas analysis on room air reveals pH
7.26, PaCO2 68 mm Hg, PaO2 54 mm Hg, and HCO3 30 mEq/L. Which
of the following oxygen delivery devices is most appropriate to initiate
controlled oxygen therapy?
A. Non-rebreathing mask at 15 L/min
B. Simple mask at 8 L/min
C. Nasal cannula at 6 L/min
D. Venturi mask delivering 28 percent oxygen
,Correct Answer: D
Rationale: Patients with chronic hypercapnia and acute on chronic
respiratory failure require controlled, low-flow oxygen therapy to
prevent the removal of their hypoxic drive and worsening hypercapnia.
A Venturi mask provides a fixed and predictable fraction of inspired
oxygen, making it the safest and most accurate choice for titration in
chronic obstructive pulmonary disease exacerbations.
Question 4
A patient is receiving volume-controlled continuous mandatory
ventilation. The high pressure alarm is sounding continuously during
inspiration. The respiratory therapist notes absent breath sounds on the
left side, tracheal deviation to the right, and subcutaneous emphysema.
Which of the following conditions is the most likely cause?
A. Mucus plugging of the right mainstem bronchus
B. Left-sided tension pneumothorax
C. Right lower lobe pneumonia consolidation
D. Severe bronchospasm affecting both lungs
Correct Answer: B
Rationale: The clinical triad of absent breath sounds on one side,
tracheal shift to the contralateral side, and subcutaneous emphysema
combined with high peak inspiratory pressures points directly to a
tension pneumothorax. This is an immediate, life-threatening
complication of mechanical ventilation that requires urgent
decompression.
Question 5
, While evaluating a patient's pulmonary function test results, the
respiratory therapist notes a total lung capacity of 55 percent of
predicted, a forced vital capacity of 60 percent of predicted, and a forced
expiratory volume in one second to forced vital capacity ratio of 85
percent. These findings are characteristic of which of the following
pulmonary disorders?
A. Chronic bronchitis
B. Asthma exacerbation
C. Pulmonary fibrosis
D. Emphysema
Correct Answer: C
Rationale: A reduced total lung capacity below the lower limit of normal
combined with a normal or elevated forced expiratory volume in one
second to forced vital capacity ratio defines a restrictive ventilatory
defect. Pulmonary fibrosis is a primary interstitial lung disease that
causes restriction, whereas chronic bronchitis, asthma, and emphysema
present with obstructive patterns.
Question 6
A patient with smoke inhalation injury is admitted to the emergency
department. Pulse oximetry reads 98 percent on room air, but the patient
remains cyanotic and confused. Arterial blood gas analysis reveals a
normal partial pressure of oxygen and a calculated oxygen saturation of
85 percent. Which of the following tests should the respiratory therapist
recommend next?
A. Repeat arterial blood gas with direct electrolyte panel
B. Co-oximetry analysis of an arterial blood sample
Answers with Rationale | Latest Edition 2026/2027
Question 1
A patient with severe acute respiratory distress syndrome is being
mechanically ventilated with a tidal volume of 4 mL/kg of predicted
body weight and a respiratory rate of 28 breaths/min. Arterial blood gas
results show pH 7.31, PaCO2 52 mm Hg, PaO2 62 mm Hg, and HCO3
26 mEq/L. Which of the following ventilator adjustments should the
respiratory therapist recommend first?
A. Increase the tidal volume to 8 mL/kg
B. Increase the respiratory rate to 34 breaths/min
C. Add or increase positive end-expiratory pressure
D. Switch to pressure control ventilation immediately
Correct Answer: C
Rationale: The patient is exhibiting refractory hypoxemia and is
managed with a lung-protective ventilation strategy using low tidal
volumes. In acute respiratory distress syndrome, increasing positive end-
expiratory pressure helps recruit collapsed alveoli, improve functional
residual capacity, and enhance oxygenation without exposing the lungs
to excessive stretch. Increasing tidal volume can cause volutrauma, and
a higher respiratory rate alone will not resolve the underlying
oxygenation deficit.
Question 2
During a pre-assessment check of a mechanical ventilator in the
intensive care unit, the respiratory therapist performs a circuit leak test
,and notes a significant difference between the set tidal volume and the
exhaled tidal volume. Which of the following components should be
inspected first?
A. The humidifier water level chamber
B. The expiratory valve and circuit connections
C. The internal oxygen blender sensor module
D. The main power supply backup battery pack
Correct Answer: B
Rationale: A discrepancy between delivered and exhaled tidal volumes
during a circuit check most commonly indicates a leak within the patient
circuit or around the expiratory valve assembly. Inspecting the tubing
connections, water traps, and the integrity of the expiratory valve
membrane is the most direct troubleshooting step to ensure accurate
volume delivery before patient connection.
Question 3
A 68 year old male with a history of chronic obstructive pulmonary
disease presents to the emergency department with acute shortness of
breath and lethargy. Arterial blood gas analysis on room air reveals pH
7.26, PaCO2 68 mm Hg, PaO2 54 mm Hg, and HCO3 30 mEq/L. Which
of the following oxygen delivery devices is most appropriate to initiate
controlled oxygen therapy?
A. Non-rebreathing mask at 15 L/min
B. Simple mask at 8 L/min
C. Nasal cannula at 6 L/min
D. Venturi mask delivering 28 percent oxygen
,Correct Answer: D
Rationale: Patients with chronic hypercapnia and acute on chronic
respiratory failure require controlled, low-flow oxygen therapy to
prevent the removal of their hypoxic drive and worsening hypercapnia.
A Venturi mask provides a fixed and predictable fraction of inspired
oxygen, making it the safest and most accurate choice for titration in
chronic obstructive pulmonary disease exacerbations.
Question 4
A patient is receiving volume-controlled continuous mandatory
ventilation. The high pressure alarm is sounding continuously during
inspiration. The respiratory therapist notes absent breath sounds on the
left side, tracheal deviation to the right, and subcutaneous emphysema.
Which of the following conditions is the most likely cause?
A. Mucus plugging of the right mainstem bronchus
B. Left-sided tension pneumothorax
C. Right lower lobe pneumonia consolidation
D. Severe bronchospasm affecting both lungs
Correct Answer: B
Rationale: The clinical triad of absent breath sounds on one side,
tracheal shift to the contralateral side, and subcutaneous emphysema
combined with high peak inspiratory pressures points directly to a
tension pneumothorax. This is an immediate, life-threatening
complication of mechanical ventilation that requires urgent
decompression.
Question 5
, While evaluating a patient's pulmonary function test results, the
respiratory therapist notes a total lung capacity of 55 percent of
predicted, a forced vital capacity of 60 percent of predicted, and a forced
expiratory volume in one second to forced vital capacity ratio of 85
percent. These findings are characteristic of which of the following
pulmonary disorders?
A. Chronic bronchitis
B. Asthma exacerbation
C. Pulmonary fibrosis
D. Emphysema
Correct Answer: C
Rationale: A reduced total lung capacity below the lower limit of normal
combined with a normal or elevated forced expiratory volume in one
second to forced vital capacity ratio defines a restrictive ventilatory
defect. Pulmonary fibrosis is a primary interstitial lung disease that
causes restriction, whereas chronic bronchitis, asthma, and emphysema
present with obstructive patterns.
Question 6
A patient with smoke inhalation injury is admitted to the emergency
department. Pulse oximetry reads 98 percent on room air, but the patient
remains cyanotic and confused. Arterial blood gas analysis reveals a
normal partial pressure of oxygen and a calculated oxygen saturation of
85 percent. Which of the following tests should the respiratory therapist
recommend next?
A. Repeat arterial blood gas with direct electrolyte panel
B. Co-oximetry analysis of an arterial blood sample
