Diagnostics & Therapeutics E1-E11 Flashcards
To convert epochs into minutes, what should you do?
Divide by 2 (an epoch is 30 seconds.)
What does it mean when “lights out” happens?
All calibrations are completed and all devices are turned off in the patient’s room.
What does it mean when “lights on” happens?
Post-calibrations are completed and the technologist awakens the patient.
If N1 is recorded in 30 epochs, how many minutes is that?
- (30 divided by 2)
How do you obtain the percent of sleep?
When you calculate it, should you include W stage?
Divide the number of minutes in that sleep stage by the total sleep time (TST), then multiply by 100.
Do not include W stage. (Do not add wake by mistake)
What is Total Recording Time?
TRT is the total testing time from lights out to lights on.
What is sleep efficiency?
The percent of time spent asleep compared to the TRT.
What is SPT and what is the definition?
Sleep Period Time
The time the individual had available to sleep.
What is sleep latency/onset?
The time in minutes from lights out until the first recorded stage of sleep.
What is an MSLT?
Multiple Sleep Latency Test
What is the median sleep latency?
The muddle number of naps (in numerical order) in an MSLT.
What is the mode sleep latency?
The number that occurs most often.
What is the Sleep REM Latency?
Sleep onset to the first epoch of stage R (in minutes)
What is the WASO?
Wake After Sleep Onset.
How do you calculate the Sleep Efficiency Percent?
TST divided by TRT or TIB x100.
What is TIB?
Time in bed
What is AI?
How is it calculated? (Two ways to calculate it.)
Apnea Index
Number of apneas divided by hours of sleep
Or
Number of apneas divided by TST x60
(When counting apneas, include central, obstructive, and mixed.)
What is the HI?
How is it calculated? (Two ways to calculate it.)
Number of hypopneas divided by hours of sleep
Or
Number of Hypopneas divided by TST in minutes.
What is the AHI?
How is it calculated? (Two ways to calculate it.)
Number of apneas + hypopneas divided by hours of sleep.
Or
Number of apneas + hypopneas divided by TST (in minutes)
Do not include RERAs.
What is the RDI?
How is it calculated (Two ways to calculate it.)
How do you calculate events per hour?
RERA + apneas + hypopneas divided by hours of sleep
Or
RERA + apneas + hypopneas divided by TST (in minutes)
NOTE: Multiply by 60 to get events per hour
What is a moderate AHI?
What is a mild and severe AHI?
Moderate is 16-30 events per hour.
Mild is 5-15, severe is 31 or greater
When calculating TRT, do you include the amount of time the patient gets out of bed to go to the bathroom?
Yes, include it.
What is normal sleep efficiency?
What does it mean if the patient has too little or too much sleep efficiency?
80-94%
Less than 80% = insomnia
More than 94% = High sleep efficiency (narcolepsy or idiopathic hypersomnia)
What is PLMS?
How do you calculate the PLMS Index? (Two ways to calculate it.)
What is a normal PLMS?
Periodic Limb Movements of Sleep. Number of PLMS divided by hours of sleep Or Number of PLMS divided by TST Fewer than 5 per hour is normal.
What is the PLMS Arousal Index?
How is it calculated? (Two ways to calculate it.)
Number of PLMS with arousals divided by hours of sleep
Or
Number of PLMS with arousal divided by TST in minutes x60
What is the saturation nadir?
Lowest recorded O2sat during the test.
When is a split-night study recommended?
AHI of 40+ during at least 2 hrs of baseline recording with at least 3 hrs of time remaining for PAP titration.
How do you calculate BMI (Body Mass Index)?
Bodyweight in pounds / Height in inches x height in inches (not a typo)
Then multiply by 703 (p. E11)
What is a normal BMI?
18.6-24.9
What is overweight BMI?
25-29.9
What is obese BMI?
30-39.9
