Free RPSGT Exam Flashcards

Standardized scalp electrode placement based on percentages of nasion-to-inion and preauricular distances. Electrodes sit at 10% or 20% intervals so recordings are reproducible across patients and labs regardless of head size.

AASM recommends F4-M1, C4-M1, and O2-M1 (with F3-M2, C3-M2, O1-M2 as backups). Frontal captures slow waves and K-complexes, central captures sleep spindles, occipital captures alpha rhythm for staging.

Keep impedances at or below 5 kilohms (ideally balanced between electrodes). High or unbalanced impedance causes 60 Hz interference and unstable signals; rub the site and re-prep rather than just increasing gain.

Eye electrodes are placed offset from the outer canthi (e.g., E1 below and E2 above) so the eyes act as dipoles. Conjugate eye movements produce out-of-phase deflections, which identify REM and slow rolling eye movements at sleep onset.

Submental EMG tone helps distinguish REM from other stages: REM shows the lowest sustained tone (atonia). Loss of atonia with movements during REM suggests REM sleep behavior disorder.

Light transitional sleep: low-amplitude mixed-frequency EEG, slow rolling eye movements, attenuation of alpha to under 50% of the epoch. Vertex sharp waves may appear. Easily aroused; brief and increased in fragmented sleep.

Defined by K-complexes and/or sleep spindles. A new N2 epoch starts with either feature unassociated with an arousal; staging continues as N2 until a stage change. Largest proportion of total sleep time in adults.

Scored when 20% or more of the epoch contains slow-wave activity: 0.5-2 Hz delta with peak-to-peak amplitude over 75 microvolts measured over the frontal derivations. Predominant in the first third of the night.

Low-amplitude mixed-frequency EEG, lowest chin EMG tone, and rapid eye movements. Sawtooth waves and transient muscle twitches support REM. REM periods lengthen across the night, longest before waking.

Spindle: 11-16 Hz (usually 12-14 Hz) burst lasting at least 0.5 seconds, maximal centrally. K-complex: well-delineated negative sharp wave followed by a positive component, total duration at least 0.5 seconds, maximal frontally.

An abrupt EEG frequency shift (alpha, theta, or over 16 Hz, not spindles) lasting at least 3 seconds, preceded by at least 10 seconds of stable sleep. In REM, a concurrent chin EMG increase of at least 1 second is also required.

A drop in airflow signal (oronasal thermal sensor) of 90% or more from baseline for at least 10 seconds. Type is set by effort: obstructive (effort continues), central (no effort), or mixed (absent then resumes).

Airflow (nasal pressure) drops at least 30% for 10 seconds or more, accompanied by a 3% or greater oxygen desaturation OR an arousal. The acceptable rule requires a 4% desaturation without the arousal criterion.

Total apneas plus hypopneas divided by total sleep time in hours. Adult severity: 5-14.9 mild, 15-29.9 moderate, 30 or greater severe. AHI under 5 is normal in adults (under 1 in children).

A sequence of breaths (at least 10 seconds) with increasing respiratory effort or flattening of the nasal pressure waveform leading to an arousal, but not meeting apnea or hypopnea criteria. Added to AHI it yields the RDI.

Cyclic crescendo-decrescendo tidal volume with central apneas/hypopneas at the nadir, cycle length typically 60 seconds or more. Strongly associated with heart failure and stroke; effort is absent during the central events.

Oronasal thermal sensor detects temperature change and is the recommended sensor to identify apneas. Nasal pressure transducer is more sensitive to subtle flow limitation and is the recommended sensor for hypopneas.

Respiratory inductance plethysmography (RIP) belts on the thorax and abdomen are recommended for effort. Paradoxical (out-of-phase) chest and abdomen movement during an event indicates an obstructive rather than central apnea.

Recommended LFF: EEG/EOG 0.3 Hz, EMG 10 Hz, ECG 0.3 Hz. Raising the EEG LFF too high attenuates slow waves and can cause under-scoring of N3; lowering it admits sweat and movement artifact.

Digital sampling must be high enough to reproduce the signal: recommended 500 Hz (minimum 200 Hz) for EEG/EOG/EMG/ECG. Under-sampling causes aliasing, distorting waveform shape and impairing accurate scoring.

Rhythmic 60 Hz contamination, usually from high or unbalanced electrode impedance or a loose electrode. First correction is to re-prep and reduce impedance; a notch filter only masks the problem and can hide real activity.

Instrument calibration sends a known voltage to verify amplifier response. Biocalibration has the patient perform maneuvers (look left/right, blink, grit teeth, breathe, hold breath) to confirm each channel records the expected physiology before recording.

Regular sharp transients time-locked to the QRS complex, more common in short-necked patients and with reference electrode problems. Re-reference or reposition rather than filter; never confuse it with epileptiform activity.

CPAP delivers one constant pressure to splint the airway. BiPAP delivers a higher inspiratory (IPAP) and lower expiratory (EPAP) pressure, improving comfort and ventilation; preferred when high CPAP is poorly tolerated or for hypoventilation.

Increase CPAP by at least 1 cm H2O at intervals no shorter than 5 minutes when obstructive events persist. The goal is to eliminate apneas, hypopneas, RERAs, and snoring in all positions and sleep stages, especially supine REM.

Optimal: residual RDI under 5 for at least 15 minutes including supine REM. Adequate: RDI 10 or lower (or reduced by 50% if baseline under 15). Lower grades guide whether a repeat or split-night study is needed.

Central apneas that appear or persist once obstructive events are controlled with PAP (complex sleep apnea). Recognize that further CPAP increases may worsen them; this finding is reported and may prompt ASV evaluation.

Diagnostic recording in the first part of the night transitions to PAP titration if a typical threshold (commonly AHI of 40 or more, or 20-40 with strong clinical findings) is met within about 2 hours, allowing diagnosis and treatment in one night.

Try a smaller or minimal-contact interface (nasal pillows), awake desensitization with the mask, relaxation techniques, or BiPAP for lower expiratory pressure. Sedation is not the appropriate first response during titration.

Add or increase oxygen (typically by 1 L/min, allowing several minutes to stabilize) to keep SpO2 at or above about 88-90% when desaturation persists despite optimized PAP. Oxygen treats hypoxemia but does not resolve obstructive events.

Adherence is commonly defined as use for at least 4 hours per night on 70% of nights over a consecutive 30-day period within the first 90 days. Documenting usage data supports continued therapy coverage.

Repetitive upper-airway collapse during sleep despite continued respiratory effort, causing desaturation and arousals. Hallmarks: loud snoring, witnessed apneas, daytime sleepiness. First-line therapy is PAP.

Repetitive cessation of airflow with absent respiratory effort due to loss of ventilatory drive. Causes include heart failure (Cheyne-Stokes), opioids, and high altitude. Effort belts show no movement during the event.

Anterior tibialis EMG bursts lasting 0.5-10 seconds, amplitude at least 8 microvolts above resting, in a series of 4 or more separated by 5-90 seconds. PLM index over 15 in adults is considered elevated.

RLS is a clinical, awake sensorimotor diagnosis (urge to move legs, worse at rest and at night, relieved by movement). PLMD is a PSG finding of periodic movements causing sleep disruption; the two often coexist but are not identical.

Multiple Sleep Latency Test: mean sleep latency of 8 minutes or less plus 2 or more sleep-onset REM periods (one may come from prior-night PSG) supports narcolepsy. A preceding adequate overnight PSG is required.

MSLT measures the tendency to fall asleep (4-5 nap opportunities, lights off, patient told to sleep). MWT measures the ability to stay awake (sit in dim room, instructed to remain awake) and is used for safety/treatment-response assessment.

Loss of normal REM atonia with dream-enactment behaviors. PSG shows excessive sustained or phasic chin/limb EMG activity during REM. Strongly associated with later synucleinopathies (Parkinson disease, dementia with Lewy bodies).

Total sleep time divided by total time in bed, expressed as a percentage. Normal adults are roughly 85% or higher. Low efficiency reflects fragmented or inefficient sleep from arousals, insomnia, or environmental factors.

Sleep latency: lights-out to the first epoch of any sleep. REM latency: sleep onset to the first epoch of REM. Short REM latency (under ~15 minutes) is a feature of narcolepsy.

Total minutes scored as wake between sleep onset and final awakening. Elevated WASO indicates sleep-maintenance difficulty and reduces sleep efficiency even when total time in bed is adequate.

Sleep is scored in sequential 30-second epochs. When two or more stages occur in one epoch, the stage occupying the greatest portion of the epoch is assigned.

The number of times per hour SpO2 drops by a defined amount (commonly 3% or 4%) from baseline. Reported alongside the AHI to characterize the oxygenation burden of sleep-disordered breathing.

Recommended maximum averaging time is 3 seconds at a heart rate of 60 bpm. Long averaging smooths and underestimates brief desaturations, which can falsely lower the scored event and desaturation counts.

The technologist confirms electrode integrity, sensor function, correct epoch-by-epoch staging, and event accuracy before the report is interpreted. Documenting montage changes and artifact lets the interpreting physician judge data validity.

Sleep-study data is protected health information. It may be released only to the patient or authorized parties with proper consent; records must be stored securely and discussed only on a need-to-know basis.

The RPSGT acquires data, applies protocols, and titrates per standing orders, but does not diagnose or independently change the medical plan. Clinical concerns and significant findings are escalated to the ordering provider.

Reusable electrodes and sensors must be cleaned and high-level disinfected per manufacturer instructions between patients; standard precautions and hand hygiene apply. Single-use items are discarded to prevent cross-contamination.

The technologist continuously monitors for clinically significant arrhythmias, severe desaturation, seizures, and falls. Recognizing a dangerous rhythm or event and activating the emergency response takes priority over data collection.

Patients are typically instructed to avoid caffeine and alcohol on the day of the study (some protocols extend caffeine restriction longer). These substances alter sleep architecture, latency, and respiratory events, confounding interpretation.