Patient Assessment & Pre-Study Evaluation Flashcards

A patient scores 18 on the Epworth Sleepiness Scale (ESS) before their overnight PSG. How should this score be interpreted?

Answer: Severe excessive daytime sleepiness warranting urgent clinical evaluation

The ESS ranges from 0 to 24. Scores of 0-10 are normal; 11-12 indicate mild sleepiness; 13-15 moderate sleepiness; and 16-24 indicate severe excessive daytime sleepiness. A score of 18 falls in the severe range and warrants urgent clinical attention, as it suggests significant impairment of waking function.

The STOP-BANG questionnaire is used in sleep medicine primarily to screen for which condition?

Answer: Obstructive sleep apnea risk stratification

STOP-BANG assesses eight risk factors (Snoring, Tired, Observed apneas, high blood Pressure, BMI >35, Age >50, Neck >40 cm, Gender male). A score ≥ 3 indicates high risk for OSA. It is widely used in preoperative and sleep clinic settings to triage patients for PSG.

A patient scheduled for an overnight PSG reports taking a nightly benzodiazepine for anxiety. How should the sleep technologist anticipate this medication will affect the study?

Answer: It will suppress N3 (slow-wave) sleep and alter overall sleep architecture

Benzodiazepines enhance GABA activity and significantly suppress slow-wave (N3) sleep while often increasing N2 sleep spindles. They also reduce REM sleep, particularly in the first half of the night. This must be noted on the PSG report as it confounds interpretation of sleep architecture.

A patient arrives for an overnight PSG having consumed three alcoholic beverages 2 hours earlier. What sleep architecture effect should the technologist anticipate?

Answer: Decreased sleep onset latency and REM suppression in the first half of the night, with REM rebound in the second half

Alcohol is a CNS depressant that shortens sleep onset latency and suppresses REM sleep early in the night as it is metabolized. As blood alcohol level drops in the second half of the night, a REM rebound occurs, often accompanied by more vivid dreams and lighter, fragmented sleep.

Before scheduling a Multiple Sleep Latency Test (MSLT) to evaluate for narcolepsy, what minimum overnight sleep requirement must be met on the prior night's PSG per AASM protocol?

Answer: At least 6 hours of total sleep time

AASM MSLT protocol requires that the patient obtain at least 6 hours of sleep on the prior night's PSG to ensure the MSLT results are valid. Insufficient overnight sleep can produce false-positive sleep-onset REM periods (SOREMPs) and spuriously shortened sleep latencies, mimicking narcolepsy.

Which pre-study instruction should a patient be given before an overnight diagnostic PSG to avoid compromising the study results?

Answer: Avoid caffeine and napping on the day of the study

Caffeine is a stimulant that delays sleep onset and reduces total sleep time and N3 sleep, all of which can confound PSG results. Napping reduces sleep pressure, making it harder to fall asleep during the study. Patients are typically instructed to avoid caffeine after noon and refrain from napping on the day of the study.