TMC Practice Exam Questions and Answers |
2026/2027
160 Questions with Correct Answers and Rationales
Therapist Multiple-Choice (TMC) Certification Preparation
2026
Aligned with NBRC TMC Detailed Content Outline,
AARC Clinical Practice Guidelines, and RRT/CRT Credentialing Standards
, TMC Practice Exam 2026/2027
Abstract
This TMC Practice Exam provides a comprehensive review of 160 multiple-choice questions designed to
prepare respiratory therapy students and professionals for the National Board for Respiratory Care
(NBRC) Therapist Multiple-Choice (TMC) examination. The exam systematically covers all major
content domains outlined in the NBRC TMC Detailed Content Outline, including patient assessment and
clinical data evaluation, airway management and intubation, mechanical ventilation modes and
management, blood gas analysis and acid-base balance, and pulmonary function testing and
interpretation. Each question is accompanied by a correct answer and detailed rationale referencing
current AARC Clinical Practice Guidelines and evidence-based respiratory care standards. Clinical
scenarios reflect real-world patient presentations encountered in critical care, emergency, neonatal, and
pediatric settings. Topics addressed include vital sign interpretation, breath sound assessment, chest X-ray
findings, arterial blood gas sampling and interpretation, pulse oximetry, capnography, oxygen delivery
devices, endotracheal tube management, ventilator mode selection and weaning protocols, lung-protective
ventilation strategies, acid-base disorder identification and compensation, spirometry interpretation, lung
volume measurements, diffusing capacity testing, flow-volume loop analysis, and bronchodilator
reversibility testing. This resource supports both Certified Respiratory Therapist (CRT) and Registered
Respiratory Therapist (RRT) credentialing preparation by reinforcing clinical judgment, critical thinking,
and evidence-based decision-making frameworks essential for safe and effective respiratory care practice.
Keywords: TMC, NBRC, respiratory therapy, mechanical ventilation, blood gas analysis, pulmonary
function testing, airway management, respiratory pharmacology
Domain 1: Patient Assessment & Clinical Data Evaluation (Questions 1-17)
1. A respiratory therapist evaluates a patient who presents with a respiratory rate of 8 breaths/min, heart
rate of 52 bpm, and SpO2 of 88% on room air. Which of the following is the most likely interpretation of
these findings?
A) Acute respiratory alkalosis with hyperventilation
B) Central nervous system depression causing hypoventilation
C) Acute asthma exacerbation with bronchospasm
D) Metabolic acidosis with respiratory compensation
2
, TMC Practice Exam 2026/2027
Correct Answer & Rationale: B) Central nervous system depression causing hypoventilation. A
respiratory rate of 8 breaths/min with bradycardia (HR 52 bpm) and hypoxemia (SpO2 88%) indicates
hypoventilation secondary to CNS depression. These findings are commonly seen with opioid overdose,
sedative use, or brainstem injury affecting the respiratory center, per AARC clinical assessment
guidelines.
2. While auscultating a patient's chest, a respiratory therapist hears fine, discontinuous, high-pitched
crackling sounds at the lung bases bilaterally during inspiration. Which of the following conditions is
most commonly associated with these breath sounds?
A) Pulmonary embolism
B) Congestive heart failure with pulmonary edema
C) Chronic bronchitis
D) Pneumothorax
Correct Answer & Rationale: B) Congestive heart failure with pulmonary edema. Fine crackles
(rales) heard at the lung bases during inspiration are classic findings in congestive heart failure with
pulmonary edema, caused by fluid-filled alveoli popping open during inspiration. Coarse crackles are
more typical of chronic bronchitis, while pneumothorax typically presents with diminished or absent
breath sounds.
3. A chest X-ray reveals a large, radiopaque area in the left pleural space with a meniscus sign and
mediastinal shift to the right. The trachea is deviated away from the affected side. What is the most likely
diagnosis?
A) Tension pneumothorax
B) Large pleural effusion
C) Atelectasis of the left lung
D) Consolidation from bacterial pneumonia
Correct Answer & Rationale: B) Large pleural effusion. A large radiopaque area with a meniscus sign
and mediastinal shift is characteristic of a large pleural effusion. Unlike tension pneumothorax, which
presents with a radiolucent (dark) area, pleural effusion appears radiopaque (white) due to fluid
accumulation in the pleural space with shift of mediastinal structures away from the affected side.
4. A respiratory therapist is preparing to perform an arterial blood gas (ABG) puncture from the radial
artery. Which of the following is the correct procedure for the modified Allen test?
A) Compress the brachial artery only and observe for pallor of the hand
3
, TMC Practice Exam 2026/2027
B) Compress both the radial and ulnar arteries, have the patient open and close the fist
until the hand blanches, release the ulnar artery, and observe color return within 5-15
seconds
C) Compress the radial artery and assess for a palpable ulnar pulse
D) Have the patient elevate the hand above heart level and observe for venous return
Correct Answer & Rationale: B) Compress both the radial and ulnar arteries, have the patient
open and close the fist until the hand blanches, release the ulnar artery, and observe color return
within 5-15 seconds. The modified Allen test requires simultaneous compression of both the radial and
ulnar arteries while the patient blanches the hand by opening and closing the fist. Upon release of the
ulnar artery, normal color return within 5-15 seconds indicates adequate collateral ulnar circulation,
confirming safety for radial artery puncture per AARC blood gas sampling guidelines.
5. A patient's pulse oximeter reads 92% SpO2, but the arterial blood gas reveals a PaO2 of 55 mmHg.
Which of the following best explains this discrepancy?
A) The pulse oximeter probe is placed on the earlobe instead of the finger
B) The patient has carbon monoxide poisoning, causing a falsely elevated SpO2 reading
C) The patient is hyperventilating, shifting the oxyhemoglobin curve to the left
D) The ABG sample was obtained from a warmed extremity
Correct Answer & Rationale: B) The patient has carbon monoxide poisoning, causing a falsely
elevated SpO2 reading. Pulse oximeters cannot differentiate between oxyhemoglobin and
carboxyhemoglobin, causing falsely elevated SpO2 readings in patients with carbon monoxide (CO)
poisoning. The actual PaO2 may be significantly lower than the SpO2 suggests because CO occupies
hemoglobin binding sites. A co-oximetry measurement is required to detect carboxyhemoglobin levels.
6. A capnography waveform shows a sudden drop in end-tidal CO2 (EtCO2) from 38 mmHg to 10 mmHg
during mechanical ventilation. Which of the following is the most likely cause?
A) The patient is developing metabolic alkalosis
B) The endotracheal tube has become displaced or there is a significant leak in the circuit
C) The patient's cardiac output has significantly increased
D) The ventilator circuit temperature has decreased, causing condensation
Correct Answer & Rationale: B) The endotracheal tube has become displaced or there is a
significant leak in the circuit. A sudden, significant drop in EtCO2 during mechanical ventilation is
most commonly caused by endotracheal tube displacement, a large circuit leak, or accidental extubation,
4
2026/2027
160 Questions with Correct Answers and Rationales
Therapist Multiple-Choice (TMC) Certification Preparation
2026
Aligned with NBRC TMC Detailed Content Outline,
AARC Clinical Practice Guidelines, and RRT/CRT Credentialing Standards
, TMC Practice Exam 2026/2027
Abstract
This TMC Practice Exam provides a comprehensive review of 160 multiple-choice questions designed to
prepare respiratory therapy students and professionals for the National Board for Respiratory Care
(NBRC) Therapist Multiple-Choice (TMC) examination. The exam systematically covers all major
content domains outlined in the NBRC TMC Detailed Content Outline, including patient assessment and
clinical data evaluation, airway management and intubation, mechanical ventilation modes and
management, blood gas analysis and acid-base balance, and pulmonary function testing and
interpretation. Each question is accompanied by a correct answer and detailed rationale referencing
current AARC Clinical Practice Guidelines and evidence-based respiratory care standards. Clinical
scenarios reflect real-world patient presentations encountered in critical care, emergency, neonatal, and
pediatric settings. Topics addressed include vital sign interpretation, breath sound assessment, chest X-ray
findings, arterial blood gas sampling and interpretation, pulse oximetry, capnography, oxygen delivery
devices, endotracheal tube management, ventilator mode selection and weaning protocols, lung-protective
ventilation strategies, acid-base disorder identification and compensation, spirometry interpretation, lung
volume measurements, diffusing capacity testing, flow-volume loop analysis, and bronchodilator
reversibility testing. This resource supports both Certified Respiratory Therapist (CRT) and Registered
Respiratory Therapist (RRT) credentialing preparation by reinforcing clinical judgment, critical thinking,
and evidence-based decision-making frameworks essential for safe and effective respiratory care practice.
Keywords: TMC, NBRC, respiratory therapy, mechanical ventilation, blood gas analysis, pulmonary
function testing, airway management, respiratory pharmacology
Domain 1: Patient Assessment & Clinical Data Evaluation (Questions 1-17)
1. A respiratory therapist evaluates a patient who presents with a respiratory rate of 8 breaths/min, heart
rate of 52 bpm, and SpO2 of 88% on room air. Which of the following is the most likely interpretation of
these findings?
A) Acute respiratory alkalosis with hyperventilation
B) Central nervous system depression causing hypoventilation
C) Acute asthma exacerbation with bronchospasm
D) Metabolic acidosis with respiratory compensation
2
, TMC Practice Exam 2026/2027
Correct Answer & Rationale: B) Central nervous system depression causing hypoventilation. A
respiratory rate of 8 breaths/min with bradycardia (HR 52 bpm) and hypoxemia (SpO2 88%) indicates
hypoventilation secondary to CNS depression. These findings are commonly seen with opioid overdose,
sedative use, or brainstem injury affecting the respiratory center, per AARC clinical assessment
guidelines.
2. While auscultating a patient's chest, a respiratory therapist hears fine, discontinuous, high-pitched
crackling sounds at the lung bases bilaterally during inspiration. Which of the following conditions is
most commonly associated with these breath sounds?
A) Pulmonary embolism
B) Congestive heart failure with pulmonary edema
C) Chronic bronchitis
D) Pneumothorax
Correct Answer & Rationale: B) Congestive heart failure with pulmonary edema. Fine crackles
(rales) heard at the lung bases during inspiration are classic findings in congestive heart failure with
pulmonary edema, caused by fluid-filled alveoli popping open during inspiration. Coarse crackles are
more typical of chronic bronchitis, while pneumothorax typically presents with diminished or absent
breath sounds.
3. A chest X-ray reveals a large, radiopaque area in the left pleural space with a meniscus sign and
mediastinal shift to the right. The trachea is deviated away from the affected side. What is the most likely
diagnosis?
A) Tension pneumothorax
B) Large pleural effusion
C) Atelectasis of the left lung
D) Consolidation from bacterial pneumonia
Correct Answer & Rationale: B) Large pleural effusion. A large radiopaque area with a meniscus sign
and mediastinal shift is characteristic of a large pleural effusion. Unlike tension pneumothorax, which
presents with a radiolucent (dark) area, pleural effusion appears radiopaque (white) due to fluid
accumulation in the pleural space with shift of mediastinal structures away from the affected side.
4. A respiratory therapist is preparing to perform an arterial blood gas (ABG) puncture from the radial
artery. Which of the following is the correct procedure for the modified Allen test?
A) Compress the brachial artery only and observe for pallor of the hand
3
, TMC Practice Exam 2026/2027
B) Compress both the radial and ulnar arteries, have the patient open and close the fist
until the hand blanches, release the ulnar artery, and observe color return within 5-15
seconds
C) Compress the radial artery and assess for a palpable ulnar pulse
D) Have the patient elevate the hand above heart level and observe for venous return
Correct Answer & Rationale: B) Compress both the radial and ulnar arteries, have the patient
open and close the fist until the hand blanches, release the ulnar artery, and observe color return
within 5-15 seconds. The modified Allen test requires simultaneous compression of both the radial and
ulnar arteries while the patient blanches the hand by opening and closing the fist. Upon release of the
ulnar artery, normal color return within 5-15 seconds indicates adequate collateral ulnar circulation,
confirming safety for radial artery puncture per AARC blood gas sampling guidelines.
5. A patient's pulse oximeter reads 92% SpO2, but the arterial blood gas reveals a PaO2 of 55 mmHg.
Which of the following best explains this discrepancy?
A) The pulse oximeter probe is placed on the earlobe instead of the finger
B) The patient has carbon monoxide poisoning, causing a falsely elevated SpO2 reading
C) The patient is hyperventilating, shifting the oxyhemoglobin curve to the left
D) The ABG sample was obtained from a warmed extremity
Correct Answer & Rationale: B) The patient has carbon monoxide poisoning, causing a falsely
elevated SpO2 reading. Pulse oximeters cannot differentiate between oxyhemoglobin and
carboxyhemoglobin, causing falsely elevated SpO2 readings in patients with carbon monoxide (CO)
poisoning. The actual PaO2 may be significantly lower than the SpO2 suggests because CO occupies
hemoglobin binding sites. A co-oximetry measurement is required to detect carboxyhemoglobin levels.
6. A capnography waveform shows a sudden drop in end-tidal CO2 (EtCO2) from 38 mmHg to 10 mmHg
during mechanical ventilation. Which of the following is the most likely cause?
A) The patient is developing metabolic alkalosis
B) The endotracheal tube has become displaced or there is a significant leak in the circuit
C) The patient's cardiac output has significantly increased
D) The ventilator circuit temperature has decreased, causing condensation
Correct Answer & Rationale: B) The endotracheal tube has become displaced or there is a
significant leak in the circuit. A sudden, significant drop in EtCO2 during mechanical ventilation is
most commonly caused by endotracheal tube displacement, a large circuit leak, or accidental extubation,
4
