This is a condition of the windpipe or the passageway that carry air into our lungs. In this condition, during sleep, the passageway starts to collapse either partially or completely, shutting the airflow and depriving the brain from oxygen. As supply of oxygen is critical to brain’s survival, its complete closure brings the patient out of sleep, and the windpipe suddenly opens up again.

How common is OSA?

It is a common problem. According to one estimate, about one billion people around the world have this condition. This is about as common as migraine.

What are the risk factors for OSA?

Main risk factors are:

Obesity, especially the neck circumference
Male gender, but probably as common in women after menopause
Middle age
Narrow throat from multiple reasons
Small chin and/or backset jaw (retrognathia)
Large tonsils and adenoids in children
Family history

What are the symptoms of OSA?

OSA may come into picture because of sleep partner’s observation of patient’s snoring and having abnormal, or stopped breathing during sleep. It may cause lack of restful feeling upon waking up. During daytime, it may cause hypersomnia or sleepiness, tiredness and fatigue, forgetfulness and other cognitive issues, anxiety, and depression. Sleepiness can be a significant risk while driving or working with heavy machinery. Untreated OSA may also lead to high blood pressure, and may increase the risk of heart disease and stroke.

What physical findings put a person at risk for OSA?

The main issue is narrowing of throat. It may happen from multiple reasons. Obesity is a risk factor but not every obese person has OSA. Throat narrowing can be from reasons a person is born with, such as small chin and/or backset jaw, large tongue, and narrow throat. Large tonsils and adenoids may make the situation worse. Obesity, especially around the neck, adds extra burden. OSA can affect young children, but is more common in middle age.

What is an apnea?

Apnea is a term for when a person stops breathing. It happens when there is no airflow in the windpipe. A sleep study keeps track of airflow in the windpipe, which stops during an apnea. Instead of ups and downs on the tracing created by airflow, one sees a straight line. Without oxygen, brain triggers a safety mechanism, waking the person up, suddenly resuming the airflow and ending the apnea.

What is a hypopnea?

Hypopnea is similar to apnea except that the airflow is not completely stopped. It is significantly less than the normal amount, and similar to an apnea, may last for many seconds.

What is an obstructive apnea?

An obstructive apnea is an apnea caused by blockage of air passage. In patients with OSA, the windpipe slowly relaxes, and may close completely and stop the airflow. This is called an obstructive type of apnea.

What is a central sleep apnea?

In this condition, the windpipe or the air passage is open but there is no flow. The cause is not mechanical blockage but rather a central mechanism that shuts the airflow. As brain cannot sustain without oxygen, this apnea is also terminated after a few seconds by waking the person from sleep.

Do patients with sleep apnea remember waking up during apnea events?

Humans do not remember waking up unless they are up for a few minutes. Apnea events usually lasts for a second or a few seconds with no recollection or memory. The person wakes up just for a few seconds, as noted on the sleep study, and goes right back to sleep.

What are difference grades of sleep apnea?

A sleep study helps to determine the number of apnea or hypopnea events a person may have during sleep. Total events are divided by the number of hours of sleep to get events per hour. Conventionally speaking, a frequency of less than 5 events (apnea + hypopneas) is considered normal. A 5-15 event per hour is mild, 15-30 is moderate, and any amount higher is considered severe. It is not uncommon to see more than 60 events an hour, which means that the patient is waking up every minute of sleep. Severity of OSA in children has different parameter: 1-5 events an hour is considered mild, 5-10 an hour is moderate, and more than 10 is considered severe.

What is oxygen saturation?

Oxygen saturation is a measure of oxygen in the blood. Oxygen saturation can be measured directly by taking a sample of blood, but most commonly it is determined by attaching a simple photoelectric device to a finger. Oxygen saturation is measured during a sleep study. Normal oxygen saturation during wakefulness or sleep is more than 90%. In OSA, it may drop significant in 80s to 70s ranges. In some conditions it drops so much that supplemental oxygen is needed to keep it within normal range.

What is a sleep study, or a polysomnogram (PSG)?

This is a study of a person’s sleep, usually overnight. Multiple electrode leads are attached to the head to monitor wakefulness and sleep, and multiple others on the body to monitor heart rate, breathing, limb, eye, and chin movements. A device is attached to a finger to monitor oxygen saturation, and another is affixed close to the nose for snoring.

When does a sleep study helpful?

Most sleep studies are performed to check for obstructive sleep apnea. It is also required to diagnose narcolepsy. It is helpful to diagnose Periodic Limb Movement disorder of Sleep but it may not require a study. Diagnosis of many other sleep conditions like insomnia, Restless Leg Syndrome, or parasomnia does not require a sleep study.

How is OSA treated?

Treatment depends upon the severity of OSA, and patient’s preferences. Treatment may become essential for people in certain professions, like long distance driving. Following are the options:

1. Position Therapy: Avoid sleeping in flat position on the back. This may help with mild cases of sleep apnea.

2. Mouth Appliance: Some patients may benefit from a mouth appliance designed by a dentist, with special training in designing it. It may be a reasonable option, if the patient can tolerate wearing it, for mild cases of OSA. Other than that, finding the right dentist may be a real issue.

3. Mask and the Machine: In most cases, it is treated with an air pressure machine, usually called a CPAP machine (CPAP stands for continuous positive airway pressure). The patient wears a nasal or a whole-face mask and, through a tube, air is pushed in the mask by the machine. Pressure from this air keeps the windpipe or the air passageway open. It is a simple mechanical solution for the collapsing airway during sleep.

Modern machines are computerized and can sense the exact timing and the amount of pressure to apply to keep the airway open. This helps to minimize the uncomfortable or the pressure feeling in the throat. This is called auto-PAP, or auto positive airway pressure. Auto-PAP is a useful option for majority of patients, but many patients with some underlying conditions require CPAP. For CPAP, patient has to be in the sleep lab to determine the right amount of pressure required to keep the windpipe open. There is an additional arrangement for the pushed air to get heated and humidified, which is quite useful especially in cold weather.

4. Surgical Treatment: There is also a surgical treatment for OSA. Main idea of surgery is to widen the throat opening. Usual approach involves removing tonsils, and clipping parts of soft palate and uvula. In some patients, a different approach is useful. Their upper and lower jaws are fractured and reset, bringing them little forward. Most patients, in my experience, are unwilling to have surgery. It may be a useful option for someone unable to use CPAP.

5. Electrical Stimulator: Yet another option is an electric stimulator, like a pacemaker, attached to a nerve in the throat or in the neck. It can be especially useful for someone not able to tolerate wearing a mask with pressure.

6. Throat Exercise: There is also some suggestion that playing a native Australian musical instrument called Didgeridoo may strengthen throat and neck muscles, and may help with OSA.

7. Medications: Finally, research is also going on to figure out a medicine to treat OSA.

What can one do to prevent OSA?

• Maintain normal weight.
• Avoid alcohol, especially before sleeping.
• Exercise regularly, including upper body.

In children, consider tonsillectomy and adenoidectomy if they are enlarged, especially if they are causing problems like frequent infection.

Children should be screened in young age, at about early middle school age, for any physical conditions that may increase risk of sleep apnea, such as small chin or backset jaw. Consult an orthodontic specialist for evaluation and treatment. Its usual treatment is a contraption that a child may wear every night for a year or two to slowly bring the jaw forward. Other than improving esthetics, it can minimize long-term issues including dental problems, and sleep apnea.

What type of doctor I need to see to be evaluated for OSA?

Sleep is a multifaceted specialty. Many different types of physicians get interested and trained to become a sleep specialist. Large part of sleep medicine is neurology, but the majority of testing performed is for sleep apnea, which has a pulmonary components. Usually, primary care physicians know exactly where to refer, based upon the type of sleep problem.

Where may I get more information about OSA?

American Academy of Neurology
American Academy of Sleep Medicine