What is a sleep study?
A sleep study or polysomnogram (PSG) is a test that electronically transmits and records specific physical activities while you sleep. The recordings become data that are manually scored and analyzed by a qualified sleep specialist to determine if you have a sleep disorder..
A sleep study is the most accurate test for diagnosing sleep apnea. It records what happens with your breathing while you sleep.
The sleep study will record :
- amount of episodes of snoring and sleep apnea (if any)
- The amount of oxygen in your blood
- Your heart rate
- Chest and abdominal movements that show whether you're making an effort to breath.
- Position in which maximum sleep apnea episodes occur.
- any abnormal limb movement .
- sleep related other disorders like narcolepsy, sleep seizure etc.
Patients will be scheduled for the sleep study with prior appointment and our technician will hook the device . The report will be scored by registered polysomnography techs (RPSGT) and a written report will be available within 36 hrs. Should you wish, we will also provide you with the treatment. Your private and confidential sleep study report can also be sent to your doctor if you wish.
Types of Sleep Studies
To diagnose sleep-related problems, doctors may use one or more of the following sleep studies:
- Polysomnogram or PSG
- Multiple sleep latency test, or MSLT
- Maintenance of wakefulness test, or MWT
- Home-based portable monitor
Your doctor may use actigraphy if he or she thinks you have a circadian rhythm disorder. This is a disorder that disrupts your body's natural sleep–wake cycle.
For a PSG, the patient usually will stay overnight at orange sleep apnea clinic. This can also be done at the comfort of the home. This study records brain activity, eye movements, heart rate, the amount of oxygen in your blood, air movement through your nose while you breathe, snoring, and chest and abdominal movements. The chest movements show whether you're making an effort to breathe . It will also record your position during sleep and whether your apnea is position dependent, it will record your snore, number of arousals, leg movements and will give an sight on other sleep disorders over and above sleep apnea.
PSG results are used to help diagnose:
- Sleep-related breathing disorders, such as sleep apnea
- Sleep-related seizure disorders
- Sleep-related movement disorders, such as periodic limb movement disorder
- Sleep disorders that cause extreme daytime tiredness, such as narcolepsy(PSG and MSLT results will be reviewed together)
Your doctor also may use a PSG to find the right setting for you on a CPAP(continuous positive airway pressure) machine.
If your doctor thinks that you have sleep apnea, he or she might schedule a split-night sleep study. During the first half of the night, your sleep is checked without a CPAP machine. This will show whether you have sleep apnea and how severe it is.
If the PSG shows that you have sleep apnea, you'll use a CPAP machine during the second half of the split-night study. A technician will help you select a CPAP mask that fits and is comfortable.
While you sleep, the technician will check the amount of oxygen in your blood and whether your airway stays open. He or she will adjust the flow of air through the mask to find the setting that's right for you. This process is called CPAP titration.
Sometimes the entire study isn't done during the same night. Some people need to go back to the sleep center for the CPAP titration study.
Also, some people might need more than one PSG. For example, your doctor may recommend a followup PSG to:
- Adjust your CPAP settings after weight loss or weight gain
- Recheck your sleep if symptoms return despite treatment with CPAP
- Find out how well surgery has worked to correct a sleep-related breathing disorder
Levels of Sleep Studies
Monitoring devices perform in-laboratory, technician-attended, overnight polysomnography (PSG)
Monitoring devices can perform full PSG outside of the laboratory. The major difference from type 1 devices is that a technologist is not present.
Monitoring devices do not record the signals needed to determine sleep stages or sleep disruption. Typically channels include:
Four physiologic variables are measured including:
- respiratory variables (eg, respiratory movement and airflow)
- Cardiac variable (eg, heart rate or an electrocardiogram)
- Arterial oxygen saturation
- Some devices may have other signals including a monitor to record snoring, detect light, or a means to determine the body position.
These devices are called continuous single or dual bioparameter devices. Monitoring devices record one or two variables and can be used without a technician. Typically channels include:
- Arterial oxygen saturation