Sleep disordered breathing (SDB), particularly the potentially life-threatening medical disorder obstructive sleep apnea, as well as the differential diagnosis of insomnia, narcolepsy, periodic limb movements of sleep, insufficient sleep syndrome, REM sleep behavior, and other medical conditions should be determined by sleep physicians, mostly based on a sleep study. 

POLYSOMNOGRAM (PSG): Polysomnogram is the most sophisticated instrumentation to record the body's activities during sleep and has been used routinely for various sleep tests, and is currently the best method to diagnose sleep breathing disorders.  It measures and records AHI, RDI, the brain waves and activity, heart rate, pulse rate, body movement, movement of eyes, length of sleep, sleep stages, number of arousals, number of apneic episodes, volume of nasal and oral airflow, loudness of snoring, unusual leg and arm movement, oxygen saturation in the blood, cardiovascular abnormalities during sleep etc.

Sleep centers and major hospitals have this instrumentation in an adjoining room where an intercom and video cameras allow communication between the patient and the sleep test technician.  Usually, recordings are done throughout the night and the record is interpreted by sleep physicians and recommended proper treatment modalities depending on the patient severity, conditions, and acceptance.

PORTABLE DIAGNOSTIC SYSTEM: Due to advances in computer science and sleep technology, a sleep study can now be performed by ambulatory device at home, where the patient feels more comfortable and can sleep without putting multiple testing electrodes around the face and body.  This is a short version of a polysomnogram and provides essential data: loudness of snoring, severity of sleep apnea, blood oxygen saturation, pulse rate, body movement and position while sleeping, wake up and sleep state, identify REM and Non-REM sleep stages etc. 

DEFINITIONS: 

• Apnea= cessation of breathing, during sleep for 10 seconds and more
• Hypopnea= >50% decrease in airflow for 10 seconds or greater with a decrease in oxygen saturation of >4%, or an arousal
• AHI (Apnea/Hypopnea Index) = apnea plus hypopnea per hour during sleep
• RDI (Respiratory Disturbance Index) = AHI + snoring + RERA (Respiratory Effort Related Arousal) 
• SaO2 scale= oxygen saturation in the blood.  >89% (nomal)  80-89% (moderate)  <80% (severe)
• REM= rapid eye movement - dreaming stage of sleep
• NREM = regular sleep stage of sleep

 SELF TESTING

SLEEP DISORDERED BREATHING SCREENING:

Are you sleepy during the day? (driving, reading, sitting in a meeting)                   Yes       No

Do you snore or have you ever been told that you snore?                                     Yes        No

Do you awake gasping or have pauses in your breathing while asleep?                 Yes       No

Do you awake with headaches?                                                                              Yes        No

Do you have difficulty falling or staying asleep?                                                       Yes        No

Do you feel un-rested despite a full night’s sleep?                                            Yes        No

If your answer is Yes to any of the above questions, you may have a sleep breathing disorder, and are recommended to have an examination and evaluation with a sleep physician.

 

THE EPWORTH SLEEPINESS SCALE:

How likely are you to doze off or fall asleep during the day in the following situations, in contrast to just feeling tired?    Use the following scale to choose the most appropriate number for each situation: 0 = would never doze   1 = slight chance of dozing,  2 = moderate chance of dozing,   3 = high chance of dozing

 Situation                                                                                                           Chance of dozing

Sitting and reading                                                                                            0      1      2      3    

Watching T.V.                                                                                                     0      1      2      3   

Sitting, inactive in a public place (meeting, theatre)                                           0      1      2      3 

As a passenger in a car for an hour without a break                                         0      1      2      3 

Lying down to rest in the afternoon when circumstances permit                       0      1      2      3

Sitting and talking to someone                                                                          0      1      2      3   

Sitting quietly after lunch without alcohol                                                           0      1      2      3  

In a car, while stopped for a few minutes in the traffic                                      0      1      2      3  

                                                                                    Total Score: __________

* Total Score: 6-7 = normal,  8-12 = mild, 13-17 = moderate,  18 and over = severe.  If your total score is 10 or more, snore and/or awake gasping for breath at night, you may have Sleep Breathing Disorders and suggested to have examination by sleep physician.