Do you suffer from snoring or episodes of choking or breathlessness in the middle of night ? Do you feel excessively sleepy during the day at work or feel difficulty in keeping up while watching television?Do you experience excessive fatigue, anxiety or irratibility even after a good night sleep? If the answer to any of the above symptoms is yes , you could be suffering from sleep disordered breathing(SDB).
Sleep apnea is temporary cessation of breathing for more than 10 seconds during sleep.It can be due to an obstructive pathology in the airway which is known as Obstructive sleep apnea(OSA) or due to defect in sleep signalling pathways from central nervous system which is known as Central Sleep Apnea. Sometimes it can be due to a combination of both which is known as Complex Sleep Apnea.
OSA is the most common cause of sleep apnea and is a very common disorder affecting 2-5% of the population worldwide.It can affect any age group ranging from children to old age but is more common in age groups between 40 to 60 years of age.Obstruction at the level of nose, oral cavity or upper digestive tract upto food pipe and dental and facial bony abnormalities can lead to airway obstruction. The airway is held open during the waking hours due to underlying tone of the muscles hence patient does not experience significant obstruction during daytime.But at night due to muscle relaxation in deep sleep and pull of gravity ,the airway collapses and patient experiences episodes of fall in blood oxygen levels with cessation of breathing or apnea.
Risk factors for developing OSA:
- Men >Women
- Increasing age
- Weight gain and obesity
- Post menopausal women
- Intake of alcohol, sedatives or tranquilizers
When should you see a doctor?
You may be suffering from OSA if you have one or more of the following warning symptoms:
- Chronic Snoring(most common symptom)
- Apneas or peroids of pauses in breathing
- Sensation of choking / breathing difficulty or gasping during sleep
- Excessive daytime sleepiness(Hypersomnia) and fatigue even after a good night sleep
- Restless sleep/Frequent arousals(Insomia)
- Going to bathroom frequently at night(Noctiuria)
- Dryness of mouth
- Acid reflux
- Sexual Dysfunction
- Morning Headaches
- Diminished quality of life
- Learning and memory difficulties
A simple way for you to assess whether you have OSA or not is by answering the Epworth Sleepiness Scale(ESS).It is a questionnaire with 8 questions and you have to rate on a scale of 0-3( 0 = would never doze 1 = slight chance of dozing 2 = moderate chance of dozing 3 = high chance of dozing). The ESS score can range from 0 to 24.
- Chance of Dozing
- Sitting and reading watching TV
- Sitting, inactive in a public place (e.g. a theatre or a meeting)
- As a passenger in a car for an hour without a break
- Lying down to rest in the afternoon when circumstances permit
- Sitting and talking to someone
- Sitting quietly after a lunch without alcohol
- In a car, while stopped for a few minutes in the traffic
The ESS score is interpreted as
0-5 Lower Normal Daytime Sleepiness
6-10 Higher Normal Daytime Sleepiness
11-12 Mild Excessive Daytime Sleepiness
13-15 Moderate Excessive Daytime Sleepiness
16-24 Severe Excessive Daytime Sleepiness
Usually a score between 11-24 warrants medical attention.
Why OSA should be treated?
Obstructive sleep apnea if untreated can lead to various long term sequelae and serious complications such as:
- Automobile accidents
- Coronary artery disease
How is OSA diagnosed?
In addition to the symptoms, important clinical signs to diagnose OSA include Hypertension, high Body Mass Index(BMI) indicating obesity and increased neck circumference.
While several investigations like Videoendoscopy, CT scan and MRI scan may be done to assess the obstructive pathology in OSA, Polysomnography is the gold standard investigation to diagnose OSA. Polysomnography or commonly called as sleep study is a test used to diagnose sleep disorders. It records important physiological parameters and body functions such as heart rate, oxygen saturation, eye movements,brain waves, chest movements, electrical activity of muscles and body positioning while the patient sleeps.This test can be done overnight at a specialized centre or even at the patient’s home. It assesses the periods of breathing cessation and periods of decreased oxygen flow to lungs and thus classifies whether patient has mild,moderate or severe OSA.
Another modality which has gained importance in recent times is Sleep Endoscopy. In this procedure the patient is taken in an operating room and under sedation by a short acting anaesthetic agent the patient is examined with endoscope to locate the exact anatomic site of snoring.
Is OSA treatable?
OSA can be treated by a number of modalities which include behavioral modifications, devices that can be worn and surgical options.
- Behavioral modifications: These can be useful in treatment of mild cases of OSA
- Sleep position therapy(patient sleeps on side or stomach instead of back)
- Weight loss where appropriate,
- Avoidance of sedatives, alcohol, or large meals before bedtime
- Devices that can be worn : Two types of devices are available
- Continuous positive airway pressure devices also known as CPAP : These are one of the most effective treatment options for moderate to severe OSA.This device is worn as a splint or mask over nose and it delivers air at a positive pressure hence it is able to overcome the obstruction in the airway.
- Oral appliances: These include mandibular repositioning devices which advance the jaw bone forward and help in bringing forward the tongue and other muscles surrounding upper airway pathway.These are useful in cases of mild OSA.
- Surgical Treatments: Surgery for OSA is usually reserved for cases who do not improve on CPAP or those cannot tolerate CPAP. Assessment of each patient has to be done individually to assess the site and level of obstruction. Various surgeries done in cases of OSA are:
- Procedures to improve compliance to CPAP in cases of obvious nasal or oral obstruction like removal of adenoids and tonsils or correction of a deviated nasal septum.
- Surgeries such as tracheostomy may be done to bypass the upper airway temporarily in cases of morbidly obese patients.Bariatric surgery may be also offered in such patients.
- Upper airway surgeries: When there is obstruction at the oral or pharyngeal level like palate,uvula,generalised contriction of the muscled of digestive tract, surgery may be done at one or more levels to create a wider space for breathing. Various surgeries done are
A).Uvuloplalatopharyngoplasty(surgery of palate and pharyngeal wall) is done to create more space behind the oral behind by repositioning of the tissues .
B).Mandibular osteatomy(surgery of the jaw bone) with tongue base advancement where the jaw bone is brought forward from the rest of facial structure to create a wider space behind the tongue
C).Maxillo-mandibular osteotomy(surgery of jaw bone and cheek bone) in severe or refractory cases.