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NBRC SDS practice questions

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Question 1Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient is scheduled for a diagnostic polysomnogram. Which parameter is measured with an oronasal thermal sensor rather than a nasal pressure transducer?

  1. Carbon dioxide via transcutaneous monitor
  2. Apnea detection via airflow cessation Correct answer.
  3. Respiratory effort via belt excursion
  4. Oxygen saturation via pulse oximetry

Explanation

Thermal sensors detect the temperature change between inspired and expired air and are recommended for scoring apneas because they reliably reflect complete airflow cessation. Nasal pressure transducers are more sensitive for hypopneas and flow limitation. Effort belts, oximetry, and capnography measure different physiologic variables.

Question 2Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

During titration of positive airway pressure for obstructive sleep apnea, the technologist observes persistent obstructive events at 10 cm H2O. What is the most appropriate next action?

  1. Switch to bilevel and hold inspiratory pressure constant
  2. Discontinue titration and refer for repeat diagnostic study
  3. Increase pressure in small increments while observing flow and leak Correct answer.
  4. Reduce pressure to improve tolerance and accept residual events

Explanation

The titration goal is to identify the pressure that eliminates obstructive events, so pressure should be raised stepwise with ongoing assessment of airflow, leak, and arousals. Holding or reducing pressure leaves obstruction untreated. Ending the study prematurely forfeits the therapeutic data the physician needs.

Question 3Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient using CPAP reports dry mouth and nasal congestion with a heated humidifier set at 1. Which adjustment is most likely to improve comfort?

  1. Switch to a nasal pillow interface without humidification
  2. Increase the humidifier setting and verify mask leak Correct answer.
  3. Lower CPAP pressure to reduce airflow velocity
  4. Decrease humidifier output to reduce condensation

Explanation

Dry mouth and congestion usually reflect inadequate humidification or mouth leak, so raising humidifier output while checking for leak addresses the cause. Reducing humidity would worsen symptoms. Changing interface or pressure does not directly correct inadequate water vapor delivery.

Question 4Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which finding on a diagnostic polysomnogram best supports a diagnosis of obstructive sleep apnea rather than central sleep apnea?

  1. Absent thoracoabdominal effort during airflow cessation
  2. Cheyne-Stokes respiration with a prolonged circulation time
  3. Preserved or increased thoracoabdominal effort during airflow cessation Correct answer.
  4. Periodic breathing with a crescendo-decrescendo pattern

Explanation

Obstructive events are characterized by continued or escalating respiratory effort against a closed upper airway while airflow stops. Absent effort defines a central event. Periodic and Cheyne-Stokes patterns are associated with central apnea, especially in heart failure.

Question 5Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient with severe COPD and obstructive sleep apnea is being titrated. Which approach reflects appropriate management of this overlap syndrome?

  1. Use CPAP at a fixed low pressure regardless of oxygenation
  2. Titrate bilevel or PAP while monitoring oxygenation and carbon dioxide Correct answer.
  3. Withhold PAP because hypercapnia contraindicates positive pressure
  4. Rely on nocturnal oxygen alone to treat obstruction

Explanation

Overlap syndrome patients need PAP titration with attention to both upper airway obstruction and ventilation, since positive pressure can also support alveolar ventilation. Oxygen alone does not relieve obstruction. Withholding PAP leaves both conditions untreated, and a fixed arbitrary pressure ignores individual needs.

Question 6Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

The multiple sleep latency test is performed the day after polysomnography. What is the standard protocol for nap opportunities?

  1. Continuous overnight recording repeated for two nights
  2. Two naps separated by four hours with actigraphy between
  3. One nap at midday with a single latency measurement
  4. Four to five naps at two-hour intervals with sleep latency measured each time Correct answer.

Explanation

The MSLT uses four or five nap opportunities spaced about two hours apart, beginning roughly two hours after the overnight study, with latency to sleep and REM onset recorded. A single or two-nap design lacks the sampling needed for interpretation. Repeating overnight studies is not the MSLT protocol.

Question 7Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient with treated obstructive sleep apnea has a residual apnea-hypopnea index of 22 events per hour on device download despite reported adherence of seven hours nightly. What is the most useful first step?

  1. Advise the patient to sleep longer each night
  2. Change to a different mask brand without reviewing data
  3. Review leak, event timing, and 95th percentile pressure on the download Correct answer.
  4. Discontinue therapy and repeat a diagnostic study

Explanation

Residual events on therapy warrant objective review of leak, pressure delivery, and event distribution before changing equipment or abandoning treatment. Leak or inadequate pressure often explains persistent events. Simply extending sleep time or switching masks blindly does not address the underlying cause.

Question 8Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

During an overnight study, a patient shows repetitive episodes of upper airway obstruction that resolve with arousal, followed by resumption of airflow. Which scoring term applies to the resumption of airflow after the event?

  1. Periodic limb movement
  2. Arousal-related flow resumption Correct answer.
  3. Hypopnea
  4. Respiratory effort-related arousal

Explanation

Events terminated by an arousal with resumption of airflow are scored as obstructive events associated with arousal. Hypopnea requires a defined flow reduction with desaturation or arousal, not merely resumption of flow. Effort-related arousals and limb movements are separate phenomena.

Question 9Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient on adaptive servo-ventilation for central sleep apnea with systolic heart failure reports worsening dyspnea. What is the most important consideration?

  1. Increase servo-ventilation pressure to suppress all central events
  2. Review the indication because ASV may be harmful in symptomatic heart failure with low ejection fraction Correct answer.
  3. Add supplemental oxygen and continue unchanged settings
  4. Switch to fixed CPAP at the highest tolerated pressure

Explanation

Adaptive servo-ventilation has been associated with increased mortality in patients with symptomatic heart failure and reduced ejection fraction, so the indication must be reassessed promptly. Simply increasing pressure or adding oxygen does not address the safety concern. Fixed high CPAP is not an equivalent substitute.

Question 10Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which device is used to measure respiratory effort during polysomnography by detecting changes in thoracic and abdominal circumference?

  1. Piezoelectric or respiratory inductance plethysmography belts Correct answer.
  2. Thermistor
  3. Snore microphone
  4. Pulse oximeter

Explanation

Effort belts use piezoelectric crystals or inductance plethysmography to translate chest and abdominal movement into an electrical signal. Thermistors measure airflow, oximeters measure saturation, and microphones detect snoring sound.

Question 11Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient is being evaluated for narcolepsy. Which MSLT finding most strongly supports the diagnosis?

  1. A single nap with sleep latency of 12 minutes
  2. Predominantly stage N3 sleep during nap opportunities
  3. Mean sleep latency under 8 minutes with two or more sleep-onset REM periods Correct answer.
  4. Mean sleep latency over 15 minutes with no REM onsets

Explanation

A short mean sleep latency combined with multiple sleep-onset REM periods is the classic MSLT signature of narcolepsy. Normal latency and absent REM onsets argue against it. A single nap is insufficient, and predominant slow-wave sleep is not characteristic.

Question 12Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient reports falling asleep while driving and has a body mass index of 38 with witnessed apneas. Which initial test is most appropriate?

  1. Home actigraphy for one week
  2. Attended overnight polysomnography Correct answer.
  3. Multiple sleep latency test as the first study
  4. Overnight pulse oximetry alone

Explanation

Attended polysomnography is indicated when there is high pretest probability of moderate to severe sleep apnea, including witnessed apneas and obesity, and it allows scoring of respiratory events and sleep architecture. Oximetry alone is insufficient for diagnosis. MSLT and actigraphy assess different questions.

Question 13Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient using bilevel positive airway pressure for obesity hypoventilation syndrome has persistent daytime hypercapnia. Which adjustment is most likely to improve ventilation?

  1. Lower expiratory pressure to zero
  2. Reduce backup rate to allow more spontaneous breathing
  3. Decrease inspiratory pressure to reduce tidal volume
  4. Increase the pressure support (inspiratory-expiratory difference) with monitoring Correct answer.

Explanation

In obesity hypoventilation, raising pressure support increases tidal volume and minute ventilation, which helps clear carbon dioxide. Decreasing inspiratory pressure reduces ventilation. Lowering backup rate or expiratory pressure does not reliably improve alveolar ventilation.

Question 14Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which instruction best prepares a patient for a home sleep apnea test?

  1. Discontinue all medications for one week beforehand
  2. Sleep in a laboratory the night before the test
  3. Apply sensors as demonstrated and record sleep time and symptoms in a log Correct answer.
  4. Avoid recording the study if sleep is fragmented

Explanation

A home study depends on correct self-application of sensors and documentation of sleep time and symptoms so the study can be interpreted. Laboratory sleep beforehand is unnecessary. Stopping medications indiscriminately is unsafe, and fragmented sleep still yields usable data.

Question 15Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A titration study shows that obstructive events disappear at 12 cm H2O but the patient develops central apneas at that pressure. What is the most appropriate interpretation?

  1. Pressure-induced central apnea requiring careful reevaluation of the optimal pressure Correct answer.
  2. Evidence that obstruction is untreated
  3. Normal finding requiring no attention
  4. Indication to discontinue all positive pressure

Explanation

Emergence of central events as pressure rises suggests treatment-emergent central apnea, which calls for reassessment of the pressure that best balances obstruction and central events. It does not mean obstruction persists. Ignoring it or abandoning therapy entirely is inappropriate.

Question 16Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which parameter from a PAP device download most directly reflects whether the patient is receiving the prescribed pressure?

  1. Leak and delivered pressure data Correct answer.
  2. Total blower hours
  3. Mask type entered by the provider
  4. Serial number of the device

Explanation

Leak and delivered pressure data show whether the prescribed pressure actually reaches the airway. Blower hours reflect usage time, not pressure delivery. Mask type and serial number are administrative details.

Question 17Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient with restless legs syndrome is scheduled for polysomnography. Which finding is most consistent with this condition during the study?

  1. Persistent snoring with inspiratory flow limitation
  2. Prolonged REM latency with reduced REM density
  3. Central apneas occurring in clusters
  4. Periodic limb movements in sleep scored from anterior tibialis EMG Correct answer.

Explanation

Periodic limb movements are scored from anterior tibialis electromyography and are commonly seen with restless legs syndrome. REM latency changes, central apneas, and flow limitation reflect other disorders and are not characteristic markers of restless legs.

Question 18Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient on CPAP has an interface that causes skin breakdown over the nasal bridge. Which action is most appropriate?

  1. Increase pressure to compensate for leak
  2. Reassess mask fit and consider a different interface or cushion Correct answer.
  3. Discontinue therapy until the skin heals completely
  4. Tighten the headgear further to reduce leak

Explanation

Skin breakdown usually results from excessive strap tension or an ill-fitting interface, so fit reassessment and an alternative cushion or mask style are appropriate. Tightening worsens pressure injury. Raising pressure does not fix the interface problem, and stopping therapy unnecessarily leaves apnea untreated.

Question 19Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which statement correctly describes the scoring of a hypopnea on polysomnography?

  1. Complete cessation of airflow for at least 10 seconds
  2. A respiratory event occurring only during REM sleep
  3. Any reduction in airflow regardless of duration or consequence
  4. A clear reduction in airflow lasting at least 10 seconds with desaturation or arousal Correct answer.

Explanation

Hypopnea requires a quantifiable airflow reduction lasting at least 10 seconds accompanied by oxygen desaturation or an arousal, depending on the scoring rules used. Complete cessation defines apnea. Duration and consequence cannot be ignored, and events are not limited to REM.

Question 20Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient with obstructive sleep apnea also has a permanent pacemaker. Which precaution applies during polysomnography?

  1. Follow device precautions and avoid placing certain sensors directly over the generator Correct answer.
  2. Cancel the study because pacemakers contraindicate polysomnography
  3. Place all electrodes directly over the device to improve signal
  4. Disable the pacemaker during the recording

Explanation

Patients with implanted cardiac devices can undergo polysomnography, but sensor placement and electromagnetic precautions should be observed to avoid interference or pressure on the generator. Canceling the study is unnecessary, disabling the device is unsafe, and placing electrodes over the generator degrades signal and risks injury.

Question 21Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A technologist notes that a patient's oxygen saturation falls repeatedly to 85% during REM sleep with associated hypopneas. What is the most appropriate response during titration?

  1. Optimize pressure to eliminate hypopneas and verify saturation response Correct answer.
  2. Ignore the desaturations because REM sleep is brief
  3. Wake the patient to interrupt REM sleep
  4. Add oxygen without addressing the hypopneas

Explanation

Desaturations from hypopneas should be corrected by optimizing positive pressure so the obstructive events resolve and oxygenation improves. Ignoring them leaves untreated hypoxemia. Oxygen alone does not treat obstruction, and deliberately interrupting sleep is not a therapeutic strategy.

Question 22Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which measure best quantifies adherence to positive airway pressure therapy for a payer review?

  1. Mean hours of use per night and percentage of nights used Correct answer.
  2. Patient-reported satisfaction score
  3. Number of masks dispensed
  4. Device serial number

Explanation

Adherence is quantified objectively from device data as average daily hours of use and the proportion of nights meeting the usage threshold. Mask counts, satisfaction ratings, and serial numbers do not measure actual use.

Question 23Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient with treatment-resistant hypertension and a high pretest probability of sleep apnea asks about testing. Which statement best reflects current practice?

  1. Hypertension excludes a diagnosis of sleep apnea
  2. Home oximetry alone is sufficient to exclude sleep apnea
  3. Overnight polysomnography is appropriate to evaluate for sleep apnea in resistant hypertension Correct answer.
  4. Sleep testing is only indicated if the patient snores

Explanation

Resistant hypertension is a recognized association with obstructive sleep apnea and supports diagnostic testing, typically attended polysomnography. Hypertension does not exclude apnea. Oximetry alone cannot exclude it, and absence of snoring does not rule it out.

Question 24Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

During polysomnography, the technologist must differentiate wake from stage N1. Which finding supports stage N1?

  1. Rapid eye movements with low chin tone
  2. Sleep spindles and K-complexes
  3. Continuous alpha rhythm with eyes closed
  4. Attenuated alpha rhythm with slow eye movements Correct answer.

Explanation

Stage N1 is characterized by attenuation of alpha activity and slow rolling eye movements. Continuous alpha indicates relaxed wakefulness. Spindles and K-complexes define N2, and REM features rapid eye movements with low chin tone.

Question 25Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient using auto-titrating CPAP reports improvement but continues to have daytime sleepiness. Which action is most appropriate?

  1. Review residual events and consider whether another cause of sleepiness exists Correct answer.
  2. Add a sedative to improve sleep continuity
  3. Stop therapy because symptoms persist
  4. Increase the pressure range arbitrarily

Explanation

Persistent sleepiness despite apparent benefit warrants review of residual events and evaluation for other causes such as insufficient sleep or another sleep disorder. Arbitrary pressure changes are not data-driven. Sedatives may worsen apnea, and stopping effective therapy is not indicated.

Question 26Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

During an overnight polysomnogram, which electrode derivation is used to identify rapid eye movements for staging REM sleep?

  1. Single frontal EEG referenced to the ipsilateral earlobe
  2. Electrooculogram referenced to the contralateral mastoid Correct answer.
  3. Pulse oximeter plethysmographic waveform
  4. Chin electromyogram referenced to the mental midline

Explanation

REM sleep is identified by conjugate, out-of-phase eye movements recorded on left and right electrooculogram channels, each referenced to the contralateral mastoid. This derivation produces the opposite-polarity deflections that distinguish true eye movements from EEG artifact. Chin EMG and oximetry support staging but do not detect eye movements.

Question 27Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient scheduled for an overnight sleep study reports taking a benzodiazepine nightly for insomnia. What is the most appropriate instruction regarding this medication before the study?

  1. Double the dose so the patient sleeps through the night
  2. Take the usual dose and document it for the interpreting clinician Correct answer.
  3. Discontinue the medication 2 weeks before testing
  4. Substitute an over-the-counter antihistamine on the night of testing

Explanation

Medications that affect sleep architecture are generally continued and documented so the clinician can interpret the study in context. Abrupt withdrawal can precipitate rebound insomnia and alter results unpredictably. The technologist records the drug, dose, and timing rather than directing changes.

Question 28Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which finding on a polysomnogram is scored as an arousal in REM sleep?

  1. An abrupt shift in EEG frequency lasting at least 3 seconds with concurrent chin EMG increase Correct answer.
  2. A transient decrease in heart rate of 5 beats per minute
  3. A single K-complex without any change in EEG frequency
  4. A burst of slow-wave activity lasting 10 seconds

Explanation

An arousal requires an abrupt shift of EEG frequency lasting at least 3 seconds, and in REM it must be accompanied by a concurrent increase in chin EMG. This EMG requirement exists because REM already shows a low-voltage mixed-frequency EEG. Isolated K-complexes or heart rate changes alone do not meet arousal criteria.

Question 29Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient with severe obstructive sleep apnea is being initiated on PAP. Which interface selection principle best supports adherence?

  1. Select the largest available cushion to prevent leak
  2. Choose the interface that fits the patient's anatomy and comfort while delivering the prescribed pressure Correct answer.
  3. Use a full-face mask only when the patient requests it in writing
  4. Always select a nasal pillow mask regardless of pressure needs

Explanation

Interface choice should balance fit, comfort, leak control, and the ability to deliver the prescribed pressure. Patient preference and anatomy both matter because poor fit drives leak and abandonment of therapy. There is no single mask type that suits all patients.

Question 30Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

During a CPAP titration, the technologist observes that obstructive events persist at 8 cm H2O but resolve at 10 cm H2O. What is the most appropriate next step?

  1. Reduce pressure to 6 cm H2O to improve comfort
  2. Maintain 10 cm H2O and verify stability across sleep stages including supine REM Correct answer.
  3. Terminate the study and refer for surgery
  4. Switch to bilevel therapy immediately

Explanation

The effective pressure must eliminate events in all sleep stages and positions, especially supine REM when obstruction is worst. Confirming stability at 10 cm H2O before ending titration ensures the prescribed pressure is adequate. Reducing pressure would allow events to recur.

Question 31Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient reports irresistible sleep attacks, cataplexy, and hypnagogic hallucinations. Which test combination best supports a diagnosis of narcolepsy?

  1. Epworth Sleepiness Scale administered twice
  2. Overnight oximetry followed by a home sleep apnea test
  3. Overnight polysomnography followed by a multiple sleep latency test Correct answer.
  4. Actigraphy alone over 2 weeks

Explanation

Narcolepsy evaluation requires overnight polysomnography followed by a multiple sleep latency test the next day. The combination documents sleep-onset REM periods and short mean sleep latency. Oximetry and questionnaires cannot establish the diagnosis.

Question 32Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A technologist is preparing to apply positive airway pressure to a patient with a tracheostomy who no longer requires the artificial airway. What action should occur before PAP initiation?

  1. Reduce prescribed pressure by half to protect the stoma
  2. Cap the tube and deliver PAP through the tracheostomy
  3. Confirm the tracheostomy has been decannulated and the stoma is closed per the care plan Correct answer.
  4. Deflate the cuff and leave the tube in place during therapy

Explanation

PAP delivered through an open or capped tracheostomy would bypass the upper airway and fail to splint it. Therapy should proceed only after the airway has been decannulated and the stoma managed per the plan of care. Pressure reduction does not correct the bypass problem.

Question 33Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which oxygen supplementation approach is preferred during a PAP titration for a patient with obesity hypoventilation syndrome?

  1. Administer oxygen by nasal cannula at 6 L/min independent of PAP
  2. Withhold oxygen entirely during titration
  3. Set oxygen at a fixed 2 L/min for the entire study
  4. Bleed oxygen into the PAP circuit and titrate to target saturation while monitoring ventilation Correct answer.

Explanation

Oxygen should be blended into the PAP circuit so the delivered FiO2 is known and saturation targets are met without masking hypoventilation. Ventilation must be monitored because supplemental oxygen can blunt the hypoxic drive and worsen CO2 retention. Fixed or independent oxygen delivery cannot be reliably titrated.

Question 34Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient using CPAP reports a dry mouth and eye irritation each morning. Which cause should the technologist evaluate first?

  1. Oxygen entrainment into the circuit
  2. Excessive humidification
  3. Inadequate pressure setting
  4. Mask or mouth leak allowing airflow across the face and mouth Correct answer.

Explanation

Dry mouth and eye irritation commonly reflect leak at the mask or through the mouth, which directs airflow across the eyes and oral mucosa. Leak should be assessed and corrected before other changes. Pressure and humidification adjustments come after leak is addressed.

Question 35Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which finding on a polysomnogram is most consistent with periodic limb movements of sleep?

  1. Slow rolling eye movements in stage N1
  2. Sustained tonic extension of all four limbs lasting 30 seconds
  3. Rhythmic jaw clenching with masseter artifact
  4. Repetitive dorsiflexion of the great toe with partial knee flexion lasting 0.5 to 10 seconds Correct answer.

Explanation

Periodic limb movements are brief, stereotyped extensions of the great toe with partial flexion of the ankle and knee, each lasting 0.5 to 10 seconds and recurring in series. They are detected on anterior tibialis EMG. Sustained posturing or jaw activity does not meet the definition.

Question 36Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient with obstructive sleep apnea is prescribed auto-titrating CPAP. Which device-derived measure best indicates that the patient is actually receiving therapy?

  1. The average mask leak
  2. The number of days used at least 4 hours Correct answer.
  3. The residual apnea-hypopnea index
  4. The 90th percentile pressure

Explanation

Usage hours above the adherence threshold demonstrate that the device is being worn and delivering pressure. Residual events, leak, and pressure statistics describe therapy quality but not whether it was used. Payers and clinicians rely on hours of use for adherence determinations.

Question 37Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient with heart failure and central sleep apnea is being considered for adaptive servo-ventilation. Which finding would argue against this therapy?

  1. Predominantly obstructive events on titration
  2. Left ventricular ejection fraction of 30% with symptomatic heart failure Correct answer.
  3. Cheyne-Stokes respiration pattern
  4. Central apnea index of 25 events per hour

Explanation

Adaptive servo-ventilation has been associated with increased mortality in patients with symptomatic heart failure and reduced ejection fraction, so it is generally avoided in that group. Central apnea index and Cheyne-Stokes pattern are features that might otherwise prompt consideration. Predominant obstruction calls for a different therapy.

Question 38Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

What is the primary purpose of the continuous positive airway pressure titration study?

  1. To determine the pressure that eliminates respiratory events across sleep stages and positions Correct answer.
  2. To measure the patient's baseline apnea-hypopnea index
  3. To evaluate daytime sleepiness objectively
  4. To assess adherence over several weeks

Explanation

A titration study identifies the pressure that controls obstructive events, ideally in supine REM as well as other stages and positions. Baseline severity is established by the diagnostic study, and adherence and sleepiness are assessed over time. The titration goal is effective pressure, not measurement of baseline disease.

Question 39Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A technologist notes that a patient's PAP pressure causes gastric insufflation and frequent awakenings. Which adjustment is most appropriate to discuss with the ordering clinician?

  1. Lower the pressure or consider bilevel therapy to reduce inspiratory pressure burden Correct answer.
  2. Change to a nasal pillow mask without other changes
  3. Increase the pressure to overcome the air swallowing
  4. Add supplemental oxygen to the circuit

Explanation

Aerophagia often reflects excessive pressure or high inspiratory effort, and reducing pressure or using bilevel support can relieve it. The goal is to maintain effective therapy while minimizing the adverse effect. Increasing pressure would worsen insufflation.

Question 40Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which statement best describes the role of the respiratory therapist in a sleep laboratory?

  1. Prescribing hypnotic medications for insomnia
  2. Performing setup, monitoring, titration, and patient education under physician direction Correct answer.
  3. Interpreting polysomnograms and issuing final diagnoses
  4. Certifying the sleep laboratory for accreditation

Explanation

Respiratory therapists in sleep medicine perform electrode and sensor setup, monitor the study, conduct PAP titrations, and educate patients. Interpretation and diagnosis remain with the qualified interpreting physician. Medication prescribing and accreditation are outside this scope.

Question 41Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient with a body mass index of 42 and daytime hypercapnia is being titrated on bilevel PAP. Which outcome best confirms adequate ventilation?

  1. Resolution of obstructive events alone
  2. Increased leak at the mask
  3. Improvement in transcutaneous or end-tidal CO2 toward normal along with oxygen saturation Correct answer.
  4. A higher respiratory rate on the device

Explanation

In obesity hypoventilation, the goal is to correct alveolar hypoventilation, which is reflected by falling CO2 and adequate oxygenation. Eliminating obstructive events alone does not ensure ventilation is adequate. Respiratory rate and leak do not directly confirm CO2 improvement.

Question 42Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient in the sleep laboratory becomes agitated and combative during an arousal from slow-wave sleep. Which initial action is most appropriate?

  1. Discontinue monitoring and discharge the patient
  2. Apply physical restraints immediately
  3. Increase the room lighting to full brightness
  4. Speak calmly, ensure safety, and allow the confusional arousal to resolve Correct answer.

Explanation

Confusional arousals from slow-wave sleep usually resolve spontaneously and are managed with calm reassurance and protection from injury. Restraints may escalate agitation and risk harm. Bright light and abrupt discharge are not indicated for a transient arousal.

Question 43Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which sensor placement is correct for recording respiratory effort by inductance plethysmography?

  1. A single band over the umbilicus only
  2. One band over the chest and one over the abdomen, both connected to the same recording system Correct answer.
  3. Bands placed over the upper thighs
  4. A band around the forehead

Explanation

Inductance plethysmography uses thoracic and abdominal bands that move with respiration and generate signals proportional to cross-sectional area change. Both belts are needed to detect paradox and to sum effort. Placement over the thighs or forehead does not reflect respiratory excursion.

Question 44Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient being evaluated for excessive daytime sleepiness has a mean sleep latency of 6 minutes and no sleep-onset REM periods on the multiple sleep latency test. Which interpretation is most appropriate?

  1. Findings are abnormal but do not meet narcolepsy criteria Correct answer.
  2. Findings are entirely normal
  3. Findings indicate idiopathic hypersomnia by definition
  4. Findings are diagnostic of narcolepsy

Explanation

A mean sleep latency under 8 minutes is abnormal, but narcolepsy criteria also require sleep-onset REM periods in most cases. Without those, the result supports pathologic sleepiness without confirming narcolepsy. Normal latency is generally above 10 minutes, and idiopathic hypersomnia requires additional criteria.

Question 45Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

During polysomnography, a patient's ECG channel shows a wandering baseline with artifact. Which action most likely corrects the problem?

  1. Remove the ECG channel from the montage
  2. Increase the paper speed
  3. Reassess and improve electrode contact and skin preparation Correct answer.
  4. Increase the ECG gain

Explanation

Wandering baseline usually reflects poor electrode contact, drying gel, or movement, so skin preparation and electrode replacement are the appropriate corrections. Adjusting gain or speed changes display only and does not fix the source. Removing the channel eliminates valuable cardiac monitoring.

Question 46Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient with obstructive sleep apnea and a high residual apnea-hypopnea index on CPAP is found to have a large mask leak and frequent mouth breathing. Which action is most appropriate?

  1. Address the leak and consider a full-face interface or chin strap Correct answer.
  2. Increase the prescribed pressure to compensate for leak
  3. Discontinue PAP and refer for an oral appliance
  4. Switch to auto-titrating mode at the same pressure range

Explanation

Leak and mouth breathing reduce delivered pressure and can produce apparent residual events. Correcting the interface and managing mouth leak should precede pressure changes. Increasing pressure or changing mode without fixing leak addresses the wrong problem.

Question 47Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which education point is most important when teaching a patient to use auto-titrating CPAP at home?

  1. The device eliminates the need for follow-up visits
  2. The device should be turned off during naps
  3. The patient should adjust the pressure range daily based on symptoms
  4. The device automatically adjusts pressure within a set range based on detected events Correct answer.

Explanation

Auto-titrating devices change pressure within clinician-set limits in response to detected events, so patients should understand that the device adjusts itself. They should not alter settings independently and still require follow-up. The device should be used for all sleep periods, including naps.

Question 48Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient with treated sleep apnea continues to report daytime sleepiness despite documented PAP use of 7 hours nightly and a residual apnea-hypopnea index of 2 events per hour. Which action is most appropriate next?

  1. Discontinue PAP because it is not working
  2. Evaluate for other causes of sleepiness such as insufficient sleep, depression, or a primary hypersomnia Correct answer.
  3. Increase the pressure setting empirically
  4. Repeat the titration study immediately

Explanation

When adherence and efficacy are documented, residual sleepiness should prompt evaluation for alternative causes rather than further pressure changes. Insufficient sleep, mood disorders, and primary hypersomnias are common contributors. Empiric pressure increases or repeat titration are unlikely to help without evidence of residual events.

Question 49Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

Which parameter should be verified before beginning a PAP titration in the sleep laboratory?

  1. The patient's preferred sleeping position
  2. The prescribed pressure range or starting pressure and the device's leak and circuit configuration Correct answer.
  3. The patient's insurance authorization number
  4. The laboratory's ambient humidity level

Explanation

Before titration, the technologist confirms the order, the starting or prescribed pressure range, and that the circuit and mask are properly assembled and leak-free. This ensures the study can proceed safely and reproducibly. Administrative and environmental details do not govern titration setup.

Question 50Sleep-focused testing and therapeutic intervention performed by respiratory therapists (detailed content outline not enumerated in source)

A patient using nocturnal noninvasive ventilation for chronic hypercapnic respiratory failure has a rising daytime CO2 level despite adherence. Which factor is most important to assess?

  1. The mask brand color
  2. The delivered minute ventilation and whether leak is reducing effective tidal volume Correct answer.
  3. The patient's caffeine intake
  4. The device's display brightness

Explanation

Persistent hypercapnia during noninvasive ventilation often reflects inadequate minute ventilation from insufficient pressure support, leak, or patient-ventilator dyssynchrony. Assessing delivered ventilation and leak guides adjustment of settings. Nonclinical factors do not explain CO2 retention.