RST Study Preparation and Instrumentation Questions and Answers

Question 1

When preparing a patient for a polysomnogram, what is the maximum acceptable impedance level for scalp and facial electrodes to ensure a high-quality recording?

Accepted Answer

5 kΩ (kilo-ohms)

Answer

According to the American Academy of Sleep Medicine (AASM) guidelines, electrode impedances for EEG and EOG channels should be at or below 5 kΩ. This ensures a strong, clear signal with minimal artifact, which is crucial for accurate sleep staging and event scoring.

Question 2

A 6-year-old child is scheduled for a polysomnogram and is visibly fearful of the electrodes and sensors. Which of the following is the MOST effective technique to facilitate the hookup process?

Accepted Answer

Use a "tell-show-do" approach, demonstrating the sensors on a doll or the parent first.

Answer

The "tell-show-do" technique is a well-established method for reducing anxiety in pediatric patients. By first explaining the procedure in simple terms (tell), then demonstrating on a non-threatening object like a doll or parent (show), and finally applying the sensor to the child (do), the technologist demystifies the process and builds trust.

Question 3

Which of the following statements BEST describes the primary operational difference between a thermal sensor (thermistor) and a thermocouple for monitoring respiratory airflow?

Accepted Answer

A thermistor measures temperature changes based on resistance, while a thermocouple measures temperature changes based on voltage.

Answer

The fundamental principle of a thermistor is that its electrical resistance changes predictably with temperature. In contrast, a thermocouple operates on the Seebeck effect, where a voltage is produced when two junctions of dissimilar metals are at different temperatures.

Question 4

A patient is scheduled for an MSLT following an overnight PSG. The technologist is reviewing the patient's medication list and sleep diary. Which of the following findings would be MOST critical to report to the physician before starting the MSLT?

Accepted Answer

The patient has been taking an over-the-counter antihistamine for allergies daily.

Answer

Many medications, including common over-the-counter antihistamines, have sedating properties and can suppress REM sleep. Their presence can significantly alter sleep latency and the occurrence of sleep-onset REM periods (SOREMPs), potentially leading to a false-negative or invalid MSLT result. This requires physician consultation before proceeding.

Question 5

During physiological calibrations prior to starting a polysomnogram, the technologist asks the patient to look left, then right, then up, then down. What is the primary purpose of this specific set of maneuvers?

Accepted Answer

To verify correct signal response and polarity of the EOG channels.

Answer

These specific eye movements create predictable, out-of-phase deflections in the left and right electrooculogram (EOG) channels. This bio-calibration allows the technologist to confirm that the EOG electrodes are placed correctly and are functioning with the correct polarity, which is essential for accurately identifying the rapid eye movements that define Stage R sleep.

RST - Registered Sleep Technologist Practice Test

RST - Registered Sleep Technologist Practice Test

RST Study Preparation and Instrumentation Questions and Answers