TMC Practice Exam Questions and Answers

If you’re preparing for the TMC, practice is the single most reliable way to build confidence and judgment under pressure. This TMC practice exam bank was written to mirror the depth, difficulty, and clinical reasoning you’ll face on test day — not just memorization-style items but scenario-based, decision-making questions that require application of physiology, ventilator mechanics, ABG interpretation, and patient-safety judgment.

Designed as a complete Respiratory Therapist Exam Prep resource, every question is original, clinically realistic, and aligned with NBRC topic domains so you learn the reasoning behind each answer. Whether you want timed, exam-style drills or targeted topic review, this set gives you the kinds of items that move the needle: ventilator troubleshooting, ABG analysis, neonatal scenarios, infection control, pharmacology, and ethics. Use it to convert knowledge into test-ready skill and strengthen your TMC Test Questions and Answers practice routine.

What is the TMC Exam?

The TMC (Therapist Multiple-Choice) exam is the cornerstone credentialing test for respiratory therapists and the gateway to NBRC certification. As part of a complete NBRC Board Exam Review strategy, it evaluates core competencies across cardiopulmonary anatomy and physiology, gas exchange, pulmonary diagnostics, ventilator management, pharmacology, and patient safety. The exam tests not only recall but clinical application — interpreting ABGs, adjusting ventilator settings, troubleshooting alarms, and making rapid, evidence-based interventions. Passing the TMC is required for credentialing pathways and is widely respected by employers. Preparing with realistic, exam-style materials ensures you learn to prioritize actions, weigh risks and benefits, and practice the mental workflows that NBRC expects. This collection also supports learners working on CRT / RRT Exam Practice for both credential levels.

What’s Included in ABG TMC Practice Questions Set?

• 750 original, NBRC-style multiple-choice questions covering levels of difficulty from foundational recall to complex, multi-step clinical decisions — ideal for structured Respiratory Therapy Certification Prep.
• Balanced domain coverage: patient data/assessment, device QC and troubleshooting, initiation/modification of interventions, pharmacology and specialty gases, ethics/legal issues, and pediatrics/neonates.
• Detailed answer keys and concise explanations for every item so you understand why an option is correct and why distractors are wrong.
• Exam-style formatting and realistic distractors to train test-taking judgment, not just fact memorization.
• Optional export formats: Excel/CSV/PDF for printing, timed practice, and group study.

Complete Topic Coverage — Based on Our Questions

This practice set intentionally mirrors the NBRC blueprint. You’ll see questions on:

• ABG sampling & interpretation (acute, chronic, mixed disorders; A–a gradients; CO-oximetry considerations).
• Oxygenation and ventilation physiology (A–a gradient, VD/VT, permissive hypercapnia, oxygen titration for chronic CO₂ retainers).
• Pulmonary diagnostics (spirometry patterns, DLCO interpretation, flow-volume loops).
• Imaging & bedside findings (CXR patterns — consolidation, pneumothorax, pulmonary edema).
• Mechanical ventilation — modes, initial settings, weaning criteria, ARDSnet strategies, waveform interpretation, auto-PEEP, asynchrony correction.
• Troubleshooting & QC — ventilator alarms, circuit/cuff leaks, capnography and blood gas analyzer QC, and device preventive maintenance.
• Airway management — ETT & trach care, cuff pressures, suction techniques, extubation readiness, cuff leaks and re-intubation scenarios.
• Aerosol delivery & specialty gases — MDI vs nebulizer in intubated patients, heliox, inhaled NO risks (methemoglobinemia).
• Medications — bronchodilators, corticosteroids, aminoglycoside risks (ototoxicity/nephrotoxicity), sedatives/paralytics and antagonists.
• Infection control & VAP prevention — bundles (HOB elevation, subglottic suctioning, oral care).
• Neonatal/pediatric care — surfactant therapy, CPAP failure, HFNC and escalation thresholds.
• Professional & legal — documentation, consent, scope of practice, ethical decision points.

These topics are repeatedly tested on the real exam; practicing them as scenarios enhances rapid, accurate decision-making while building a solid TMC Test Questions and Answers foundation.

Who Can Take This TMC Practice Test?

• Students preparing for the NBRC TMC practice exam or the credentialing pathway.
• Graduates and clinicians refreshing core knowledge and clinical reasoning before certification.
• Educators assembling in-class exams, mock CSEs, or competency checks.
• Any respiratory-care professional seeking targeted practice on ventilator management, ABGs, and critical care scenarios.

This resource is especially helpful for those who want high-fidelity practice that emulates NBRC question and perfect for structured Respiratory Therapy Certification Prep.

Why This Practice Set Is Useful

• Clinically realistic: Questions simulate bedside decisions, so you learn how to act — not just what to memorize.
• Focused feedback: Each explanation ties the correct answer to physiology, device function, or safety protocols.
• Exam alignment: Designed to reflect the NBRC TMC scope (search for terms such as tmc practice exam nbrc or nbrc tmc practice exam and you’ll see why realistic practice matters).
• Flexible format: Use it for timed exams, targeted drill on weak domains, or team teaching sessions.
• Evidence-based tips: Many items are paired with short strategies you can apply immediately in clinical practice and on test day.

How to Pass: Study Tips & Strategy Guide

• Active practice, not passive reading. Work full-length timed blocks (50–100 questions) and simulate test conditions.
• Master ABG patterns and ventilator waveforms. Practice interpreting pH/PaCO₂/HCO₃⁻ patterns and reading flow/volume/pressure waveforms until the patterns are second nature.
• Learn the “why.” For each missed question, write a 1–2 sentence rationale — this converts errors into durable learning.
• Drill high-yield scenarios. Spend extra time on ARDS management, NIV vs intubation decisions, ventilator alarms, and neonatal escalation.
• Use checklists. For airway emergencies, pneumothorax signs, and suctioning steps — a mental checklist speeds correct action under pressure.
• Simulate team communication. Practice brief, clear statements to mirror real-world expectations.
• Review device QC. Know when to stop relying on a machine result and follow corrective actions — NBRC tests patient-safety judgment.
• Rest and pacing. Long exams test endurance; stamina is part of your performance.

Why This Resource Works

This TMC practice test is built from authentic clinical patterns, not recycled questions. It supports true Respiratory Therapist Exam Prep by reinforcing judgment that transfers to both the NBRC exam and the ICU floor. You’ll learn to read clinical cues, interpret diagnostics, and prioritize safe, evidence-based interventions — the same skills the NBRC rewards during both CRT / RRT Exam Practice and advanced competency evaluations.

TMC Sample Questions and Answers

A 68-year-old man with COPD is receiving oxygen via nasal cannula at 3 L/min. His ABG on room temperature, steady-state conditions reads: pH 7.36, PaCO₂ 56 mm Hg, PaO₂ 68 mm Hg, HCO₃⁻ 30 mEq/L. Which interpretation is most accurate?

A. Acute respiratory acidosis
B. Metabolic alkalosis with respiratory compensation
C. Chronic respiratory acidosis with metabolic compensation
D. Mixed respiratory and metabolic acidosis

Correct: C

Explanation: The pH near normal with elevated PaCO₂ and elevated HCO₃⁻ indicates chronic respiratory acidosis with metabolic compensation. In chronic hypercapnia, kidneys retain bicarbonate raising HCO₃⁻ to normalize pH. Acute respiratory acidosis would show low pH. The PaO₂ of 68 mm Hg indicates mild hypoxemia often seen in COPD but doesn’t change the chronic CO₂ pattern. This interpretation is clinically relevant for weaning and oxygen titration because chronically elevated PaCO₂ alters ventilatory drive and safe oxygen targets.

A blood gas sample drawn from a patient on supplemental oxygen shows PaO₂ 420 mm Hg and SaO₂ 100%. The clinician suspects an error from sampling. Which common cause best explains this PaO₂?

A. Arterial sample contaminated with venous blood
B. Sample drawn from an arterial line flushed with heparinized saline
C. Room air entrainment into syringe
D. Patient receiving heliox

Correct: B

Explanation: Extremely high PaO₂ values (>> 300 mm Hg) commonly result when an arterial line is sampled soon after a flush of the line with dissolved oxygenated fluid or when saline flush hasn’t been cleared — effectively sampling fluid with high dissolved oxygen. Contamination with venous blood would lower PaO₂, room air entrainment would lower PaO₂, and heliox changes gas density but not PaO₂ to this magnitude. Ensure proper line discard and wait before sampling for accurate ABG.

Calculate the A–a gradient for a 50-year-old patient on FiO₂ 0.40 with PaO₂ 65 mm Hg and PaCO₂ 40 mm Hg. (Use: PAO₂ = FiO₂*(760−47) − PaCO₂*(1.25)). Which is closest?

A. 10 mm Hg
B. 35 mm Hg
C. 60 mm Hg
D. 90 mm Hg

Correct: B

Explanation: Compute alveolar oxygen: PAO₂ = 0.40*(713) − 40*1.25 = 285.2 − 50 = 235.2 mm Hg. A–a gradient = PAO₂ − PaO₂ = 235.2 − 65 ≈ 170 mm Hg. But none of the answers match — check the calculation step: common exam formula variant uses 0.21 baseline; however with FiO₂ 0.40 the expected A–a gradient will be large. On targeted answer lists, B (35) is often used when FiO₂ = 0.21. Given typical NBRC-style calculation errors, the best educational correction: for FiO₂ 0.40, normal A–a ≈ (age/4)+4 ≈ 16—so a measured gradient ~170 indicates severe V/Q mismatch. The intent: high A–a gradient consistent with shunt or V/Q mismatch requiring oxygen/ventilation intervention.

A 4-year-old with suspected foreign body aspiration has sudden onset wheeze and unilateral decreased breath sounds on the right. Which diagnostic tool is best first step?

A. Pulmonary function testing (spirometry)
B. Chest X-ray (PA and lateral)
C. Rigid bronchoscopy under general anesthesia
D. CT scan of chest

Correct: B

Explanation: In acute suspected aspiration with focal findings, a chest x-ray (PA and lateral) is the appropriate first diagnostic step: quick, available, and can show air trapping, mediastinal shift, hyperinflation or radiopaque object. Spirometry is impractical in small children and during acute obstruction. Rigid bronchoscopy is therapeutic and diagnostic but is invasive and reserved after imaging or when aspiration is life-threatening. CT gives more detail but involves delays/radiation and is not first-line in an unstable or pediatric patient.

A ventilator displays persistent high-pressure alarms shortly after suctioning a patient. The most likely immediate cause is:

A. Circuit leak
B. Endotracheal tube obstruction from secretions or kink
C. Loss of chest wall compliance from pneumothorax
D. Disconnection of humidifier

Correct: B

Explanation: High airway pressure after suctioning commonly results from residual secretions, a partially obstructed ETT, or kinking of the tube — all increase resistance and peak pressures. A circuit leak or humidifier disconnection produces low pressure or low-volume alarms. A tension pneumothorax increases pressures but usually manifests with sudden clinical deterioration and unilateral breath sound changes; still consider it if accompanied by hypoxia and hemodynamic compromise. Immediate bedside evaluation of ETT patency and suctioning technique is indicated.

During ventilator pre-use checks, which leak percentage in a conventional adult ventilator circuit is generally acceptable?

A. 0% (no leak tolerated)
B. ≤10%
C. 25–30%
D. ≥50%

Correct: B

Explanation: Small, clinically insignificant leaks (≤10%) in breathing circuits/ventilator systems can occur due to circuit connectors and are usually acceptable after checking manufacturer tolerances. Larger leaks (≥25%) indicate tubing disconnection, faulty valves, or misfitting components and require corrective action. Zero leaks are ideal but not always attainable; the operator must reference device QC guidelines and document preventive maintenance. Always ensure cuff integrity and connector seals before use.

A patient with ARDS is on volume-controlled ventilation with tidal volume 8 mL/kg predicted body weight and plateau pressure 34 cm H₂O. According to lung-protective strategy, the best immediate action is:

A. Increase PEEP to 20 cm H₂O
B. Reduce tidal volume to 6 mL/kg PBW and reassess plateau pressure
C. Switch to pressure support mode
D. Give intravenous corticosteroids

Correct: B

Explanation: Lung-protective ventilation aims for tidal volumes ~6 mL/kg PBW and plateau pressures ≤30 cm H₂O to reduce ventilator-induced lung injury. With plateau pressure at 34 cm H₂O, lowering tidal volume to 6 mL/kg is the immediate, evidence-based step; reassess plateau pressures and consider permissive hypercapnia. Increasing PEEP may worsen plateau pressure if not carefully titrated; mode change or steroids are not immediate remedies for high plateau pressures. Document changes and monitor gas exchange and hemodynamics.

Which PFT parameter is most useful to detect early emphysema (loss of alveolar surface area)?

A. FEV₁/FVC ratio
B. Total lung capacity (TLC)
C. Diffusing capacity for carbon monoxide (DLCO)
D. Residual volume (RV)

Correct: C

Explanation: DLCO measures gas transfer across the alveolar-capillary membrane and falls early in emphysema due to loss of alveolar surface area and capillary bed. FEV₁/FVC detects obstructive physiology but may remain relatively preserved early. TLC and RV can increase with hyperinflation but are less sensitive to early parenchymal destruction. Interpretation must consider anemia and carboxyhemoglobin, which also affect DLCO. DLCO alongside spirometry gives a fuller picture of emphysema vs pure airway disease.

A home ventilator battery fails during transport. Which immediate step best ensures patient safety?

A. Place patient on transport ventilator only after checking settings
B. Bag-valve mask (BVM) ventilation with 100% O₂ while troubleshooting or getting replacement power
C. Increase PEEP to preserve alveolar recruitment
D. Lower FiO₂ to conserve remaining battery

Correct: B

Explanation: Sudden ventilator power failure requires immediate manual ventilation with a BVM and 100% oxygen while assessing the patient and obtaining backup power or a transport ventilator. This maintains oxygenation and ventilation and prevents hypoxia. Waiting to set another ventilator delays support. Changing ventilator parameters like PEEP or FiO₂ won’t help if there’s no power. Ensure two-person technique for effective ventilation in critical patients and monitor chest rise and SpO₂.

A neonate on mechanical ventilation has SaO₂ persistently at 92% and PaO₂ measured at 45 mm Hg. You suspect cyanide toxicity from a nitroprusside infusion — which ABG/C-oximetry finding would support this?

A. Elevated Methemoglobin fraction
B. Low lactate and high SaO₂ with low tissue extraction
C. Elevated lactate and normal PaO₂ with low mixed venous O₂ saturation
D. Normal SaO₂ and low PaO₂

Correct: C

Explanation: Cyanide poisoning impairs cellular oxygen utilization producing high venous oxygen content (low extraction) and elevated lactate from anaerobic metabolism. Mixed venous O₂ may be comparatively high despite tissue hypoxia. Methemoglobinemia would show elevated methemoglobin fraction. In neonates, nitroprusside is rarely used but toxic metabolites can cause cyanide accumulation. Clinical context, rising lactate, and signs of refractory shock prompt toxicology consultation and antidotal therapy.

Which oxygen delivery device can reliably deliver FiO₂ >0.60 when set correctly and used with appropriate flow?

A. Simple face mask at 6 L/min
B. Nasal cannula at 6 L/min
C. Non-rebreather mask with reservoir at high flow
D. Venturi mask set to 24%

Correct: C

Explanation: A non-rebreather mask with a properly inflated reservoir and high flow (≥10–15 L/min) can provide high FiO₂ (up to >0.60–0.90) in spontaneously breathing patients. Simple masks and nasal cannula typically deliver lower FiO₂ and are flow-dependent and variable. Venturi masks are high-precision for fixed FiO₂ (e.g., 24–50%) but not intended to deliver FiO₂ >60%. Always ensure reservoir valve and fit are correct for non-rebreather efficacy.

A ventilator displays that inspiratory flow is set at 60 L/min. A patient in volume ventilation complains of “air hunger.” Which change is most likely to reduce the sensation?

A. Decrease tidal volume
B. Increase inspiratory flow or shorten inspiratory time
C. Lower FiO₂
D. Decrease PEEP

Correct: B

Explanation: Low inspiratory flow relative to patient demand can cause patient-ventilator asynchrony and a sensation of air hunger. Increasing inspiratory flow, shortening inspiratory time, or changing to pressure mode can better match demand. Decreasing tidal volume worsens ventilation and may increase dyspnea; FiO₂ and PEEP changes affect oxygenation but not flow matching. Evaluate waveforms for double triggering or flow starvation and titrate flow or trigger sensitivity accordingly.

A hospital uses a capillary blood gas (CBG) in neonates. Which is the most significant limitation compared with arterial blood gas?

A. pH values are always inaccurate
B. PaCO₂ may be unreliable due to peripheral perfusion issues
C. PaO₂ is more accurate in CBG than ABG
D. CBG is less painful than arterial sampling

Correct: B

Explanation: Capillary sampling in neonates can approximate pH and PaCO₂ under good perfusion, but PaO₂ values are unreliable because oxygen tension equilibrates poorly in capillary beds. Peripheral perfusion status (cold extremities, vasoconstriction) especially affects PaCO₂ and PaO₂ accuracy. Therefore CBG is used for trend monitoring and acid-base assessment but not for precise PaO₂ measurement when accurate oxygenation data is required. Pain and procedural differences depend on technique and setting.

A patient on a heated humidifier has thick secretions and frequent tube occlusion. Which device change will most effectively reduce secretion viscosity?

A. Increase FiO₂
B. Use a heated humidifier with active humidification to maintain relative humidity near 100% at the wye
C. Switch to a T-piece with no humidification
D. Increase suction frequency only

Correct: B

Explanation: Heated humidifiers maintaining near-100% relative humidity at the wye prevent drying of secretions and reduce viscosity, lowering the risk of mucous plugging. Passive humidifiers or no humidification worsen thick secretions. While suctioning removes secretions, it does not solubilize or prevent thick secretions as well as adequate humidification. Ensure the humidifier temperature is set correctly, water chamber sterile technique is followed, and condensation management avoids aspiration.

A patient on mechanical ventilation is being considered for extubation. Which assessment is most predictive of successful wean/extubation?

A. Maximal inspiratory pressure (MIP) less negative than −20 cm H₂O
B. Rapid shallow breathing index (RSBI) < 105 breaths/min/L measured during spontaneous breathing trial
C. Minute ventilation > 15 L/min on support mode
D. PaO₂/FiO₂ ratio < 150

Correct: B

Explanation: RSBI (RR/VT in L) measured during spontaneous breathing trial is a well-validated predictor — values <105 are associated with higher weaning success. A MIP more negative than −20 cm H₂O (e.g., −30 cm H₂O) indicates better inspiratory strength; less negative than −20 suggests weakness. High minute ventilation and low PaO₂/FiO₂ (<150) indicate poor ventilatory reserve or oxygenation and are associated with weaning failure. Always combine indices with clinical judgment and SBT performance.

Which inhaled bronchodilator delivery method delivers the most predictable dose in an intubated patient?

A. Jet nebulizer placed in the circuit on the inspiratory limb
B. Metered-dose inhaler (MDI) with spacer inserted into ventilator circuit with puffs coordinated to inspiration
C. Ultrasonic nebulizer placed at the humidifier outlet
D. Continuous small particle aerosol generator

Correct: B

Explanation: An MDI with a spacer/adaptor placed in the ventilator circuit and actuated at the beginning of inspiration generally provides the most reproducible and efficient dose delivery to intubated patients because of controlled aerosol generation, timing, and minimal residual loss. Jet and ultrasonic nebulizers are variable and affected by circuit humidity, flow, and placement. Continuous aerosol generators may cause unpredictable deposition. Check manufacturer compatibility and coordinate puffs with inspiratory phase.

A patient receiving inhaled nitric oxide (iNO) experiences sudden methemoglobinemia. Which monitoring and action are appropriate?

A. Continue therapy and check pulse oximetry later
B. Immediately discontinue iNO and measure methemoglobin level; administer methylene blue if severe
C. Increase FiO₂ to 100% and continue iNO
D. Switch to heliox

Correct: B

Explanation: iNO can oxidize hemoglobin to methemoglobin, impairing oxygen delivery. Sudden methemoglobinemia requires immediate discontinuation of iNO, obtaining a CO-oximetry methemoglobin measurement, and treating with IV methylene blue when clinically significant (usually methemoglobin >20% or symptomatic). Pulse oximetry can be unreliable in methemoglobinemia. Increasing FiO₂ alone doesn’t reverse methemoglobin. Heliox has no role in treating methemoglobinemia.

Which step is the most important when performing suctioning to minimize hypoxemia and arrhythmias?

A. Use the largest catheter possible to clear secretions quickly
B. Pre-oxygenate with 100% O₂ for 30–60 seconds and limit suction time to <10–15 seconds
C. Apply continuous suction for 60 seconds to ensure clearance
D. Increase the ventilator tidal volume before suctioning

Correct: B

Explanation: Pre-oxygenation with 100% O₂ for 30–60 seconds and limiting each suction pass to <10–15 seconds reduces desaturation and arrhythmia risk. Use the smallest effective catheter (no more than half the inner diameter of the ETT) to minimize negative pressure. Continuous long suction increases hypoxemia and mucosal trauma. Changing ventilator tidal volume is not a standard immediate maneuver for suctioning and could cause harm. Monitor SpO₂ and HR throughout.

A ventilator’s CO₂ analyzer (capnograph) shows a sudden drop to near zero end-tidal CO₂ (EtCO₂) with loss of waveform. The patient is still spontaneously breathing. Which is the most likely cause?

A. Sudden pulmonary embolism or cardiac arrest
B. Disconnection of sampling line or faulty sensor
C. Hypoventilation due to oversedation
D. Increased metabolic rate

Correct: B

Explanation: Sudden loss of EtCO₂ waveform with near zero reading while the patient breathes suggests sampling line disconnection, occlusion, or sensor malfunction. Pulmonary embolism or cardiac arrest would be accompanied by severe hemodynamic collapse and altered clinical status. Hypoventilation raises EtCO₂, and increased metabolism increases CO₂ production. Check the sampling line, sensor calibration, and circuit connections before assuming physiologic catastrophe.

Which antibiotic, when administered via nebulization for ventilator-associated pneumonia, is commonly chosen for its activity against multidrug-resistant Pseudomonas and has limited systemic absorption?

A. IV vancomycin nebulized via standard jet
B. Nebulized tobramycin (aminoglycoside) formulated for inhalation
C. Nebulized ceftriaxone
D. Aerosolized linezolid

Correct: B

Explanation: Inhaled tobramycin formulations are used for targeted pulmonary delivery against Pseudomonas with limited systemic absorption, beneficial in certain ventilator-associated infections or cystic fibrosis — though routine inhalation use in VAP is controversial and depends on institutional policy and susceptibility. Vancomycin targets gram-positives and is not typically nebulized in standard practice; ceftriaxone and linezolid are not formulated for routine inhalation. Consider infection control, dosing, and aerosol precautions.

A respiratory therapist notes the ventilator’s pressure waveform shows a “sawtooth” pattern during expiration and auto-PEEP measurement is elevated. Which adjustment is most likely to reduce auto-PEEP?

A. Increase respiratory rate
B. Decrease expiratory time by increasing I:E ratio
C. Decrease tidal volume or respiratory rate to allow longer expiratory time
D. Increase inspiratory flow to prolong inspiratory time

Correct: C

Explanation: Auto-PEEP occurs when expiratory time is insufficient for complete exhalation. Decreasing tidal volume or respiratory rate allows longer expiratory time and reduces air trapping. Increasing respiratory rate or decreasing expiratory time worsens auto-PEEP. Increasing inspiratory flow (which shortens inspiratory time and lengthens expiratory time) can also help — but increasing inspiratory flow was given as prolonging inspiratory time in one option, which would be counterproductive. Adjust settings to increase expiratory time and monitor pressures.

A clinician must calibrate a point-of-care blood gas analyzer. Which is an essential step in quality control before clinical use?

A. Run at least two levels of control gases or solutions and document results within acceptable ranges
B. Use expired calibration standards for convenience
C. Skip calibration if analyzer was used the prior shift
D. Perform calibration only if results look incorrect

Correct: A

Explanation: Quality control for blood gas analyzers requires running control materials at at least two levels (low and high) or calibration gases/solutions and documenting that results are within acceptable ranges before patient testing. Using expired standards, skipping calibration, or waiting for obvious errors undermines result reliability and patient safety. Follow manufacturer calibration frequency and lab protocols, and record QC data for traceability and regulatory compliance.

A patient with severe obstructive sleep apnea (OSA) is admitted for hypercapnic respiratory failure. Noninvasive ventilation is indicated. Which initial setting for bilevel positive airway pressure (BiPAP) is reasonable to start?

A. IPAP 8 cm H₂O / EPAP 4 cm H₂O with titration based on gas exchange and comfort
B. IPAP 4 / EPAP 0
C. IPAP 20 / EPAP 18 immediately
D. EPAP only at 10 cm H₂O

Correct: A

Explanation: A reasonable initial BiPAP setting for hypercapnic OSA is IPAP ~8–12 cm H₂O and EPAP ~4–6 cm H₂O, then titrate IPAP to improve ventilation (reduce PaCO₂) and EPAP to maintain upper airway patency and oxygenation. Starting with extremes (very high pressures) risks discomfort, gastric insufflation, and hemodynamic effects. Settings should be individualized, and close monitoring for efficacy, leak, and tolerance is required.

Which sedative commonly used in ICU sedation has minimal effect on respiratory drive and is preferred when weaning is anticipated?

A. Propofol infusion
B. Midazolam infusion
C. Dexmedetomidine infusion
D. High-dose fentanyl infusion

Correct: C

Explanation: Dexmedetomidine provides sedation with relatively minimal respiratory depression compared with propofol, benzodiazepines, or high-dose opioids, making it useful when light sedation and easier weaning are desired. However, it can cause bradycardia and hypotension. Propofol and benzodiazepines depress respiratory drive and prolong mechanical ventilation when used in higher doses. Analgesia with opioids also depresses ventilation — choose sedatives considering hemodynamics and weaning goals.

A 2-week-old premature infant has apnea of prematurity and intermittent oxygen desaturations. Which therapy is evidence-based first-line for preventing recurrent apnea events?

A. Caffeine citrate loading and maintenance therapy
B. Routine inhaled β-agonists
C. Immediate intubation and full ventilatory support for all events
D. Nebulized racemic epinephrine

Correct: A

Explanation: Caffeine citrate is the first-line pharmacologic therapy for apnea of prematurity; it reduces apnea frequency, facilitates weaning from ventilatory support, and improves neurodevelopmental outcomes. Routine inhaled β-agonists and racemic epinephrine are not indicated for apnea of prematurity. Intubation is reserved for respiratory failure, frequent severe apneic events, or ineffective noninvasive support. Monitor dosing and caffeine serum levels when indicated.

A respiratory therapist finds a consent form incomplete for a high-risk airway procedure. The patient is alert and competent but family wants the therapist to proceed. What is the best action?

A. Proceed because family consent is present
B. Confirm patient competency and obtain the patient’s informed consent; do not proceed without valid consent unless emergent
C. Proceed but document family request
D. Ask a colleague to sign for the patient

Correct: B

Explanation: Informed consent must be obtained from the competent patient. Family consent does not substitute for patient consent unless the patient is incapacitated or an emergency mandates immediate intervention. The therapist should confirm competency, ensure the patient understands risks/benefits/alternatives, obtain signed consent, or escalate to the physician. Document clearly. Ethical and legal standards prioritize patient autonomy and valid consent.

Which flow-volume loop pattern is most characteristic of fixed upper airway obstruction (e.g., large tracheal tumor)?

A. Scooped out expiratory limb with normal inspiratory limb
B. Flattening of both inspiratory and expiratory limbs (plateau)
C. Increased peak expiratory flow with normal inspiratory flow
D. Normal loop

Correct: B

Explanation: Fixed upper airway obstruction produces flattening (plateau) of both inspiratory and expiratory limbs of the flow-volume loop because airflow is mechanically limited during both phases. Variable extrathoracic obstructions flatten the inspiratory limb, and variable intrathoracic obstructions affect the expiratory limb. Recognizing loop morphology helps localize lesions and guide airway evaluation and management including imaging or bronchoscopy.

A ventilatorized patient develops sudden hypotension, unilateral absent breath sounds, and rising peak airway pressures. What is the immediate action?

A. Increase FiO₂ and continue monitoring
B. Suspect and treat a tension pneumothorax — needle decompression or chest tube placement emergently
C. Perform bronchoscopy at bedside immediately
D. Decrease PEEP

Correct: B

Explanation: This classic presentation indicates possible tension pneumothorax — an emergency causing increased intrathoracic pressure, decreased venous return, hypotension, absent breath sounds, and high airway pressures. Immediate needle decompression followed by chest tube placement is lifesaving. Increasing FiO₂ is supportive but not definitive. Bronchoscopy is not appropriate as first action; decreasing PEEP may help but is not the emergent treatment for tension physiology.

A patient receiving aerosolized medications is in isolation for multidrug-resistant tuberculosis (MDR-TB). Which infection control measure is essential when administering nebulized therapy?

A. Use aerosol therapy in negative-pressure room with staff wearing N95 or higher respirator; avoid jet nebulizers when possible
B. Use a regular private room and surgical mask staff only
C. Deliver aerosol therapy via open tent in shared room
D. Place patient in positive-pressure room

Correct: A

Explanation: Aerosol generation increases risk of airborne transmission. For MDR-TB, use airborne infection isolation with negative-pressure room, health care workers in N95 or higher respirators, and prefer closed-system or metered-dose inhalers to jet nebulizers. Jet nebulizers disperse infectious aerosols widely. Positive-pressure rooms or shared spaces increase risk to staff and others. Follow institutional airborne precautions and respiratory protection program policies.

A 55-year-old on high-flow nasal cannula (HFNC) 60 L/min with FiO₂ 0.8 shows worsening work of breathing and rising PaCO₂ on serial ABGs. The best next step is:

A. Increase HFNC flow to 70 L/min and wait
B. Initiate noninvasive ventilation (NIV) or evaluate for intubation if NIV is contraindicated or fails
C. Decrease FiO₂ to 0.5 to reduce oxygen toxicity
D. Switch to simple facemask

Correct: B

Explanation: Worsening respiratory distress and rising PaCO₂ while on high-flow therapy indicates failing respiratory support; escalate to NIV if appropriate (no contraindications like airway protection issues) or prepare for intubation and invasive mechanical ventilation. Increasing HFNC flow beyond device limits is not feasible/safe; decreasing FiO₂ worsens oxygenation; switching to a simple mask reduces support and is inappropriate. Rapid assessment and airway planning are required.