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NBRC TMC CRT/RRT Examination – Latest Updated
Comprehensive Study Guide and Practice Exam (PDF Format)
1. A patient receiving oxygen from an E cylinder at 4 L/min through a nasal cannula has a cylinder pressure of 1900
psig. How long will the cylinder run until completely empty?
A. 47 minutes
B. 1.7 hours
C. 2.2 hours
D. 3.6 hours
C. 2.2 hours The E cylinder constant is 0.28; multiply 1900 by 0.28 to get 532 L, then divide by the flow rate of 4
L/min to get 133 minutes, which equals 2.21 hours.
2. After setting up a nonrebreathing mask on a patient at 10 L/min, the reservoir bag collapses before inspiration
ends. What should the respiratory therapist do?
A. Change to a simple mask at 10 L/min
B. Remove the one-way valve from the exhalation port
C. Place the patient on continuous positive airway pressure
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D. Increase the flow rate to 15 L/min
D. Increase the flow rate to 15 L/min The reservoir bag collapsing indicates inadequate flow to meet the patient's
inspiratory demand; increasing the flow rate to 15 L/min will ensure the bag remains inflated during inspiration.
3. A patient with carbon monoxide poisoning would best benefit from which oxygen therapy device?
A. Nasal cannula at 6 L/min
B. Simple oxygen mask at 10 L/min
C. CPAP with 60% oxygen
D. Nonrebreathing mask
D. Nonrebreathing mask Carbon monoxide has a higher affinity for hemoglobin than oxygen; a nonrebreathing
mask delivers the highest possible FiO2 (approaching 100%) to displace CO from hemoglobin binding sites.
4. Blood gas results from a patient on a 60% aerosol mask show pH 7.47, PaCO2 31 mmHg, and PaO2 58 mmHg.
What should the therapist recommend?
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A. Place the patient on CPAP
B. Increase oxygen to 70%
C. Intubate and initiate mechanical ventilation
D. Change to a nonrebreathing mask
A. Place the patient on CPAP The patient is hypoxemic despite high FiO2, indicating refractory hypoxemia likely
from shunting; CPAP recruits alveoli and improves oxygenation by reducing intrapulmonary shunting.
5. Using the following data, calculate the total arterial oxygen content: pH 7.41, PaCO2 37 mmHg, PaO2 88 mmHg,
HCO3 26 mEq/L, SaO2 95%, Hb 14 g/dL.
A. 12 mL/dL
B. 14 mL/dL
C. 16 mL/dL
D. 18 mL/dL
D. 18 mL/dL Using the oxygen content formula: (Hb × 1.36 × SaO2) + (0.003 × PaO2) = (14 × 1.36 × 0.95) +
(0.003 × 88) = 18.088 + 0.264 = 18.35 mL/dL.
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6. A tachypneic patient in the ED breathing at 35 breaths/min needs moderate oxygen delivery. Which device is most
appropriate?
A. Simple oxygen mask at 10 L/min
B. Nasal cannula at 4 L/min
C. Nonrebreathing mask at 15 L/min
D. Air-entrainment mask at 40% oxygen
D. Air-entrainment mask at 40% oxygen Tachypneic patients have variable inspiratory flow demands; air-
entrainment masks deliver a fixed FiO2 with high total flow that meets or exceeds the patient's peak inspiratory
flow.
7. A severe COPD patient on 2 L/min nasal cannula has ABG results: pH 7.32, PaCO2 67 mmHg, PaO2 62 mmHg,
HCO3 38 mEq/L. What is the most appropriate recommendation?
A. Increase the liter flow to 4 L/min
B. Maintain the current oxygen level
C. Institute noninvasive positive pressure ventilation
D. Place on a nonrebreathing mask at 12 L/min
NBRC TMC CRT/RRT Examination – Latest Updated
Comprehensive Study Guide and Practice Exam (PDF Format)
1. A patient receiving oxygen from an E cylinder at 4 L/min through a nasal cannula has a cylinder pressure of 1900
psig. How long will the cylinder run until completely empty?
A. 47 minutes
B. 1.7 hours
C. 2.2 hours
D. 3.6 hours
C. 2.2 hours The E cylinder constant is 0.28; multiply 1900 by 0.28 to get 532 L, then divide by the flow rate of 4
L/min to get 133 minutes, which equals 2.21 hours.
2. After setting up a nonrebreathing mask on a patient at 10 L/min, the reservoir bag collapses before inspiration
ends. What should the respiratory therapist do?
A. Change to a simple mask at 10 L/min
B. Remove the one-way valve from the exhalation port
C. Place the patient on continuous positive airway pressure
,2
D. Increase the flow rate to 15 L/min
D. Increase the flow rate to 15 L/min The reservoir bag collapsing indicates inadequate flow to meet the patient's
inspiratory demand; increasing the flow rate to 15 L/min will ensure the bag remains inflated during inspiration.
3. A patient with carbon monoxide poisoning would best benefit from which oxygen therapy device?
A. Nasal cannula at 6 L/min
B. Simple oxygen mask at 10 L/min
C. CPAP with 60% oxygen
D. Nonrebreathing mask
D. Nonrebreathing mask Carbon monoxide has a higher affinity for hemoglobin than oxygen; a nonrebreathing
mask delivers the highest possible FiO2 (approaching 100%) to displace CO from hemoglobin binding sites.
4. Blood gas results from a patient on a 60% aerosol mask show pH 7.47, PaCO2 31 mmHg, and PaO2 58 mmHg.
What should the therapist recommend?
,3
A. Place the patient on CPAP
B. Increase oxygen to 70%
C. Intubate and initiate mechanical ventilation
D. Change to a nonrebreathing mask
A. Place the patient on CPAP The patient is hypoxemic despite high FiO2, indicating refractory hypoxemia likely
from shunting; CPAP recruits alveoli and improves oxygenation by reducing intrapulmonary shunting.
5. Using the following data, calculate the total arterial oxygen content: pH 7.41, PaCO2 37 mmHg, PaO2 88 mmHg,
HCO3 26 mEq/L, SaO2 95%, Hb 14 g/dL.
A. 12 mL/dL
B. 14 mL/dL
C. 16 mL/dL
D. 18 mL/dL
D. 18 mL/dL Using the oxygen content formula: (Hb × 1.36 × SaO2) + (0.003 × PaO2) = (14 × 1.36 × 0.95) +
(0.003 × 88) = 18.088 + 0.264 = 18.35 mL/dL.
, 4
6. A tachypneic patient in the ED breathing at 35 breaths/min needs moderate oxygen delivery. Which device is most
appropriate?
A. Simple oxygen mask at 10 L/min
B. Nasal cannula at 4 L/min
C. Nonrebreathing mask at 15 L/min
D. Air-entrainment mask at 40% oxygen
D. Air-entrainment mask at 40% oxygen Tachypneic patients have variable inspiratory flow demands; air-
entrainment masks deliver a fixed FiO2 with high total flow that meets or exceeds the patient's peak inspiratory
flow.
7. A severe COPD patient on 2 L/min nasal cannula has ABG results: pH 7.32, PaCO2 67 mmHg, PaO2 62 mmHg,
HCO3 38 mEq/L. What is the most appropriate recommendation?
A. Increase the liter flow to 4 L/min
B. Maintain the current oxygen level
C. Institute noninvasive positive pressure ventilation
D. Place on a nonrebreathing mask at 12 L/min
