NBRC TMC CRT Credential Exam Questions
and Verified Answers with Rationale | Latest
Edition 2026/2027
Question 1
A 55-year-old male with a history of chronic obstructive pulmonary
disease is admitted to the emergency department in acute respiratory
distress. Arterial blood gas analysis on room air reveals: pH 7.31,
PaCO2 62 mm Hg, PaO2 52 mm Hg, and HCO3 31 mEq/L. Which of
the following is the most appropriate oxygen therapy device to initiate?
A. Non-rebreathing mask at 15 L/min
B. Venturi mask delivering a controlled FiO2 of 0.24 to 0.28
C. Simple face mask at 8 L/min
D. Nasal cannula at 6 L/min
Correct Answer: B
Rationale: Patients with chronic hypercapnia and chronic obstructive
pulmonary disease are at risk of worsening hypoventilation if high,
unmonitored concentrations of oxygen are administered. A Venturi mask
provides a precise, controlled fraction of inspired oxygen, allowing
target oxygen saturations of 88 to 92 percent to be achieved safely
without inducing acute respiratory depression.
Question 2
While reviewing a patient's chart, a respiratory therapist notes a plateau
pressure of 34 cm H2O, a peak inspiratory pressure of 48 cm H2O, a
,positive end-expiratory pressure of 5 cm H2O, and a delivered tidal
volume of 500 mL. What is the patient's static lung compliance?
A. 12.5 mL/cm H2O
B. 17.2 mL/cm H2O
C. 20.0 mL/cm H2O
D. 35.0 mL/cm H2O
Correct Answer: B
Rationale: Static compliance is calculated using the formula: Tidal
Volume / (Plateau Pressure - PEEP). Plugging in the values: 500 / (34 -
5) = = 17.2 mL/cm H2O. Normal static compliance for an
intubated adult ranges from 40 to 60 mL/cm H2O.
Question 3
An adult patient is intubated with an 8.0 mm internal diameter
endotracheal tube. The respiratory therapist performs a cuff pressure
measurement using a manometer and records a reading of 38 cm H2O.
Which of the following complications is most likely to occur if this
pressure is maintained?
A. Spontaneous extubation
B. Tracheal mucosal ischemia, necrosis, and subsequent tracheal
stenosis
C. Severe respiratory alkalosis
D. Acute alveolar hyperinflation
Correct Answer: B
,Rationale: Tracheal capillary perfusion pressure typically ranges
between 25 and 35 cm H2O. Maintaining cuff pressures above this safe
threshold occludes mucosal capillaries, leading to ischemia, tissue
necrosis, and scarring over time.
Question 4
A 45-year-old female is evaluated for weaning from mechanical
ventilation. Her spontaneous respiratory rate is 28 breaths per minute,
tidal volume is 250 mL, and maximum inspiratory pressure is -18 cm
H2O. What is the patient's rapid shallow breathing index (RSBI), and is
she a candidate for a weaning trial?
A. RSBI is 64 breaths/min/L; she is a strong candidate for weaning.
B. RSBI is 112 breaths/min/L; she exceeds the threshold and may fail
weaning.
C. RSBI is 140 breaths/min/L; she is ready for immediate extubation.
D. RSBI is 50 breaths/min/L; she has profound muscle weakness.
Correct Answer: B
Rationale: The rapid shallow breathing index is calculated as Frequency
/ Tidal Volume (in liters). First, convert tidal volume to liters: 250 mL =
0.25 L. RSBI = .25 = 112 breaths/min/L. An RSBI greater than
105 breaths/min/L is generally predictive of weaning failure.
Question 5
During the resuscitation of an adult cardiac arrest patient, an
endotracheal tube is placed. Which of the following is considered the
most reliable bedside method to confirm correct tracheal placement?
A. Observing condensation inside the clear plastic tube wall
, B. Continuous waveform capnography showing exhaled carbon
dioxide
C. Bilateral chest movement inspection alone
D. Auscultation of breath sounds over the epigastric region
Correct Answer: B
Rationale: Continuous waveform capnography provides definitive, real-
time confirmation of proper endotracheal tube placement in the trachea
by detecting exhaled carbon dioxide, outperforming auscultation or
visual condensation checks in reliability.
Question 6
A patient with severe status asthmaticus is intubated and mechanically
ventilated. The high-pressure limit alarm sounds frequently.
Auscultation reveals widespread expiratory wheezing and diminished
breath sounds. Which of the following ventilator modifications is most
appropriate to address dynamic hyperinflation (auto-PEEP)?
A. Increase the respiratory rate and tidal volume.
B. Decrease the inspiratory flow rate or increase peak flow to shorten
inspiratory time and lengthen expiratory time.
C. Eliminate all positive end-expiratory pressure.
D. Switch to inverse ratio ventilation immediately.
Correct Answer: B
Rationale: In obstructive diseases like status asthmaticus, air trapping
(auto-PEEP) occurs due to insufficient expiratory time. Increasing
inspiratory flow shortens inspiratory time, thereby lengthening the time
available for exhalation.
and Verified Answers with Rationale | Latest
Edition 2026/2027
Question 1
A 55-year-old male with a history of chronic obstructive pulmonary
disease is admitted to the emergency department in acute respiratory
distress. Arterial blood gas analysis on room air reveals: pH 7.31,
PaCO2 62 mm Hg, PaO2 52 mm Hg, and HCO3 31 mEq/L. Which of
the following is the most appropriate oxygen therapy device to initiate?
A. Non-rebreathing mask at 15 L/min
B. Venturi mask delivering a controlled FiO2 of 0.24 to 0.28
C. Simple face mask at 8 L/min
D. Nasal cannula at 6 L/min
Correct Answer: B
Rationale: Patients with chronic hypercapnia and chronic obstructive
pulmonary disease are at risk of worsening hypoventilation if high,
unmonitored concentrations of oxygen are administered. A Venturi mask
provides a precise, controlled fraction of inspired oxygen, allowing
target oxygen saturations of 88 to 92 percent to be achieved safely
without inducing acute respiratory depression.
Question 2
While reviewing a patient's chart, a respiratory therapist notes a plateau
pressure of 34 cm H2O, a peak inspiratory pressure of 48 cm H2O, a
,positive end-expiratory pressure of 5 cm H2O, and a delivered tidal
volume of 500 mL. What is the patient's static lung compliance?
A. 12.5 mL/cm H2O
B. 17.2 mL/cm H2O
C. 20.0 mL/cm H2O
D. 35.0 mL/cm H2O
Correct Answer: B
Rationale: Static compliance is calculated using the formula: Tidal
Volume / (Plateau Pressure - PEEP). Plugging in the values: 500 / (34 -
5) = = 17.2 mL/cm H2O. Normal static compliance for an
intubated adult ranges from 40 to 60 mL/cm H2O.
Question 3
An adult patient is intubated with an 8.0 mm internal diameter
endotracheal tube. The respiratory therapist performs a cuff pressure
measurement using a manometer and records a reading of 38 cm H2O.
Which of the following complications is most likely to occur if this
pressure is maintained?
A. Spontaneous extubation
B. Tracheal mucosal ischemia, necrosis, and subsequent tracheal
stenosis
C. Severe respiratory alkalosis
D. Acute alveolar hyperinflation
Correct Answer: B
,Rationale: Tracheal capillary perfusion pressure typically ranges
between 25 and 35 cm H2O. Maintaining cuff pressures above this safe
threshold occludes mucosal capillaries, leading to ischemia, tissue
necrosis, and scarring over time.
Question 4
A 45-year-old female is evaluated for weaning from mechanical
ventilation. Her spontaneous respiratory rate is 28 breaths per minute,
tidal volume is 250 mL, and maximum inspiratory pressure is -18 cm
H2O. What is the patient's rapid shallow breathing index (RSBI), and is
she a candidate for a weaning trial?
A. RSBI is 64 breaths/min/L; she is a strong candidate for weaning.
B. RSBI is 112 breaths/min/L; she exceeds the threshold and may fail
weaning.
C. RSBI is 140 breaths/min/L; she is ready for immediate extubation.
D. RSBI is 50 breaths/min/L; she has profound muscle weakness.
Correct Answer: B
Rationale: The rapid shallow breathing index is calculated as Frequency
/ Tidal Volume (in liters). First, convert tidal volume to liters: 250 mL =
0.25 L. RSBI = .25 = 112 breaths/min/L. An RSBI greater than
105 breaths/min/L is generally predictive of weaning failure.
Question 5
During the resuscitation of an adult cardiac arrest patient, an
endotracheal tube is placed. Which of the following is considered the
most reliable bedside method to confirm correct tracheal placement?
A. Observing condensation inside the clear plastic tube wall
, B. Continuous waveform capnography showing exhaled carbon
dioxide
C. Bilateral chest movement inspection alone
D. Auscultation of breath sounds over the epigastric region
Correct Answer: B
Rationale: Continuous waveform capnography provides definitive, real-
time confirmation of proper endotracheal tube placement in the trachea
by detecting exhaled carbon dioxide, outperforming auscultation or
visual condensation checks in reliability.
Question 6
A patient with severe status asthmaticus is intubated and mechanically
ventilated. The high-pressure limit alarm sounds frequently.
Auscultation reveals widespread expiratory wheezing and diminished
breath sounds. Which of the following ventilator modifications is most
appropriate to address dynamic hyperinflation (auto-PEEP)?
A. Increase the respiratory rate and tidal volume.
B. Decrease the inspiratory flow rate or increase peak flow to shorten
inspiratory time and lengthen expiratory time.
C. Eliminate all positive end-expiratory pressure.
D. Switch to inverse ratio ventilation immediately.
Correct Answer: B
Rationale: In obstructive diseases like status asthmaticus, air trapping
(auto-PEEP) occurs due to insufficient expiratory time. Increasing
inspiratory flow shortens inspiratory time, thereby lengthening the time
available for exhalation.
