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Snoring & Sleep Disorders Clinic

Madras ENT Research Foundation was one of the first centers to start a sleep laboratory in Chennai. Dr. P. Vijaya Krishnan is the Consultant ENT Surgeon, Heads the Department of Snoring & Sleep Disorders. He is one of the International Scientific Committee member of the World Association of Sleep Medicine (WASM). He is the Founder Secretary of Indian Association of Surgeons for Sleep Apnoea (IASSA). This has facilities for Level 1 Polysomnography to monitor sleep related breathing disorders like Snoring & Obstructive Sleep Apnoea Syndrome (OSAS) and Drug Induced Sleep Endoscopy to identify the level of obstruction. Coblation is used for performing Uvulopalatopharyngoplasty and maxillomandibular surgeries including Genioglossus and Hyoid Advancement for patients with heroic snoring and OSAS.

What is sleep apnea?
Sleep apnea is a type of sleep disorder characterized by pauses in breathing during sleep. Each pause in breathing is called an Apnea, can last from at least ten seconds to several minutes, and may occur 5 to 30 times or more an hour. Similarly, each abnormally shallow breathing event is called a Hypopnea.

Sleep apnea symptoms

  1. Intermittent Snoring
  2. Feel dizzy or tired in the morning
  3. Headaches or concentration problems
  4. Overweight and excessive sweating
  5. Often getting up from sleep to go to the toilet
  6. High blood pressure
  7. Sexual Problems
"The Suffer's who doesn't suffer".
An estimated 10% to 30% of adults snore. In some of them, snoring may have no serious medical consequences. However, for others, loud nightly snoring may be the first indication of a potentially life-threatening disorder called obstructive sleep apnea syndrome (OSAS) or simply Obstructive Sleep Apnea.

During sleep, respiration and heart rate decreases and blood pressure and body temperature changes. An insufficient sleep or problems affecting the functions and health.

Apnea is a temporary interruption of breathing. People suffering from sleep apnea stop breathing repeatedly during sleep, for periods ranging from several seconds to a minute or more.

Obstructive apnea is caused by upper airway occlusion. Apnea occurs when throat muscles and tongue relax during sleep and partially or completely blocks the airway. Risk factors may be obesity, enlarged tonsils and adenoids.

If within an hour the patient has at least ten interruptions in breathing, each lasting at least 10 seconds each, the amount of oxygen reaching the brain is insufficient. In this case, the concentration of carbon dioxide in the blood increases heart rate variations occur. Decrease in oxygen concentration triggers a partial awakening (arousals), together with a snore powerful and sudden inspiration. These arousals remain unnoticed by the patient, but produce a superficial sleep. This light sleep leads to poor recovery of the body during the night and daytime sleepiness and fatigue.

Patients suffering from sleep apnea often feel very tired and sleepy during the day and their ability to concentrate and daytime performance suffer dramatically.
If you have OSAS, you may not get enough oxygen during sleep and probably don't sleep "soundly". You may suffer daytime sleepiness that affects your work and/or social activities, and may even lead to car accidents. OSAS can also put you at risk for high blood pressure, heart failure, heart attack, or stroke. Snoring loudly every night, in all positions, calls for a visit to a sleep specialist.
Asleep At The Wheel
As you get sleepy you lose the will power to pull off the road. Dozing off while driving can have tragic consequences. Research suggests it contributes to more accidents than was previously suspected. Proper treatment can prevent or reverse the potentially life-threatening results of osas. Click this following link to see a video.
Sleep Lab
Our sleep lab is designed to evaluate, diagnose, treat and help patients to manage OSA. The sleep study is a painless process conducted on the patient at night, whereby the patient has to sleep without any sedative. A specially trained technologist puts the patient on nasal thermistar to measure the nasal air flow, a mic to record the snoring, sensors to the head, face, chest, abdomen and legs. Our State-of-the-art polysomnograph monitors brain waves, breathing, blood oxygen levels, heart rate, snoring and muscle activity during sleep. On the next day the patient will receive a complete sleep report which defines and diagnoses the sleep-related problem. If the test is positive, then on the second night the patient sleeps with the CPAP machine, which prevents the air passage from choking. The air pressure at which the patient needs to sleep is detected by the titration machine.

Instructions for the patient who undergo sleep study

  1. Have to come around 9 PM after light dinner
  2. Have to bring one attendee
  3. Sleep study will be getting over by 6 AM
  4. Reports can be collected by 6 PM
  5. The treatment plan involves control of weight, to increase physical exercise to build up muscle tone, use of CPAP machine while sleeping and surgery.
Polysomnogram (Sleep Study)
Without Thee what is all the morning's wealth?
Come, blessed barrier between day and
Dear mother of fresh thoughts and joyous health!
by William Wordsworth

A Sleep Study or Polysomnogram (PSG)is a multi-component test, which electronically transmits and records specific physical activities while you sleep. The recordings become data, which will be "read" or analyzed by a qualified physician to determine whether or not you have a sleep disorder.
There are 4 types of Polysomnographic Studies. They are:

  • Diagnostic Overnight PSG - General monitoring and evaluation of sleep & sleep disorders.
  • Diagnostic Daytime Multiple Sleep Latency Test (MSLT) - Used to diagnose Narcolepsy and measure the degree of daytime sleepiness. To ensure accurate results, it is performed on the morning following a Diagnostic Overnight PSG.
  • Two Night PSG with CPAP Titration - General monitoring and diagnostic evaluation is conducted on the first night. If Sleep Apnea is discovered, the patient returns for a second night to determine the necessary CPAP pressure required to alleviate his / her apnea.
  • Split Night PSG with CPAP Titration - Split Night PSG is conducted when moderate or severe Sleep Apnea has been discovered or strongly suspected during the first part of the night study. The second half of the night is used for CPAP Titration.

Let's get started about Sleep Study

It's the night of your sleep study. Hopefully, you have followed the directions given by the consultant regarding meals, medication and other issues, so that they don't interfere with the sleep study results. For example, alcohol or caffeine / sleeping pills can interfere with your sleep and should be avoided. It will be better if you could get up early in the morning on the day of sleep study and not to sleep in the daytime. Better to have a light dinner and have less water, to avoid frequent getting up from bed for going to rest room which can cause disconnection of electrodes. You will be provided disposable urine can, in case you need it.
Pack up a small bag with your paijamas / night dress, drinking water, towel, toothbrush and any other items you will need the next morning and bring it along. Many patients like to bring their own pillow / bed spread and blanket for better sleep.
You will be escorted to sleep lab after admission. Staff nurse will be taking the reading of your pulse, blood pressure, height, weight and neck circumference. You will be asked to fill up a questionnaire to quantify your day time sleepiness.
You will be asked to wear your paijamas / night dress of your comfort before the process of attaching the surface electrodes (leads) begins.
Once you are affixed with electrodes and the preparation is over, you may have some time to relax before dropping off to sleep. Most clinics allow the patient to choose their bedtime, within reason. Televisions will not be provided, but you may bring a book or magazine. Also, the technician can adjust your bedroom's temperature according to your personal preference.
Setup process can take 15 - 30 minutes or more in order to get everything connected properly. There are a large number of supplies that are used in the process, as you can see in the photo. The two blue belts are placed around your chest and abdomen to measure your respiratory efforts, and the band-aid like oximeter probe on your finger measures the amount of oxygen in your blood. The electrodes are temporarily "glued" to your skin and scalp. Don't worry, the glue comes off easily the next morning merfmk
This set up tray contains additional items for a patient hookup including: paper tissues, electrode wires, marking pencils, tape measure, gauze pads, hair clips, cotton swabs, alcohol pads and glue bottles that will help secure the electrodes.
The key part of a sleep study is understanding what is happening while you sleep. By attaching the electrodes to your body, the electrical signals generated by your brain and muscular activity are sent back through the wires and recorded digitally. The pattern of this activity can be recognized by our sleep specialist who "reads" or interprets the study. These valuable clues reveal whether or not you have a sleep disorder, and if present, how severe it is.
This is a close up view of the gold plated surface electrodes that will be glued to the skin and scalp during the PSG. They will record the extremely low levels of electrical energy present during any muscular or brain activity.
During placement of the electrodes the patient usually sits in a comfortable chair.
Chest/Abdomen Belts: Records breathing depth, apnea and hypopnea events. Elastic belts are placed around your chest and abdomen.
Nasal Airflow Sensor: Records breathe temperature, airflow, apnea and hypopnea events. A sensor is placed near your nose and mouth.
The EEG or electroencephalogram, is a major part of a sleep study. It measures and records four forms of brain wave activity - alpha, beta, delta and theta waves.
The EMG or electromyogram, records muscle activity such as face twitches, teeth grinding, and leg movements. It also helps in determining the presence of REM stage sleep.
The EOG or electro-oculogram, records eye movements. These movements are important in determining the different sleep stages, particularly REM stage sleep. The electrodes are usually placed on the outer aspect of your right eyebrow and along the outer aspect below or beneath your left eye.
The EKG or electrocardiogram, records heart activities, such as rate and rhythm. Electrodes are placed on your chest.
Oximeter: Records blood oxygen saturation. A band-aid like clip is placed on a finger.
Position sensor: Records body positioning and movements.
During sleep, our brain and body cycle between NREM and REM sleep approximately every 90 minutes.
During these transitions, major changes occur in our EEG, EOG, EMG, heart rate and respiration that are necessary for healthy sleep. If abnormal changes are observed during a particular sleep stage, then we are able to define this problem as it occurs during the night.
Some sleep disorders are generally worse in a particular sleep stage, such as sleep apnea during REM sleep and Periodic Leg Movement Disorder (PLMD) in NREM sleep. PSG technician and sleep specialist are well aware of these facts and want you to get as good a night's sleep as possible in order to make your test experience as pleasant as possible.
Although being hooked up with many wires and belts which may look uncomfortable and sleeping through the night seems impossible, most patients fall asleep without any difficulty.
A CPAP Titration is required if sleep apnea is diagnosed or strongly suspected. Typically, this is a full night study performed during a second night, but is sometimes performed during the last few hours of a split-night study.
To properly treat sleep apnea, the correct CPAP air pressure setting must be determined by titration. Titration is done for each patient - there is no "one size fits all" solution.
During a titration study, the patient will sleep all wired up, just like a normal sleep study, but they will also wear a nasal mask which is connected to a CPAP machine.
During the titration study, the technician will set the air pressure on the CPAP at a certain level and then watch the resulting measurements. If that pressure does not reduce the number of apnea and hypopnea events, or eliminate the snoring, the technician will adjust the air pressure and continue observation. This process continues throughout the night until the optimum pressure is reached.
After the study is over (mostly around 6 am), technician will come and disconnect all the electrodes. You have to fill up the sleep study questionnaire to describe the sleep and the experience you had during the study. You can collect the discharge summary and leave the Sleep Lab. Usually the report will be ready by 6 pm on the day of discharge. You can make a call and confirm with the reception before coming to collect the report.
We hope that the information we have provided will be of immense help to you, to be well prepared for your sleep study.
"We wish you a Healthy Life free of Sleep Apnoea"
For any further clarifications please contact ENT Surgeon on duty
Dept. of Snoring and Sleep Disorders

Snoring and Sleep Disorders Clinic
Tue, Thurs and Alternate Saturday
8 am – 10 am