Obstructive Sleep Apnea

An Introduction to Sleep Apnea

Sleep Apnea is a condition in which the airway is obstructed during sleep. The body can not receive oxygen and leaves deeper levels of sleep, such as REM sleep, in an attempt to restore airflow. CPAP is the gold standard treatment for sleep apnea. We have prepared an in depth article about Sleep Apnea which covers the history, types and treatment options relating to the disease.

History of Sleep Apnea

A Historical Overview of Sleep Apnea

Sir William Olser in 1918 first used a term he invented, "Pickwickian", to describe patients who were both obese and hypersomnolent. Olser was obviously a reader of Charles Dickens as the Dickens novel Pickwick Papers had a character in it that was similar to the patients he had identified with these common symptoms. Around 1956, Dr. Burwell was treating patients who often had congestive heart failure, extreme sleepiness or fatigue, as well as improper airflow to the lungs; or respiratory failure. He termed these types of patients as having Pickwickian Syndrome.

Early Diagnosis and Treatment

In 1965 a group of French and German doctors lead by Dr. Gastaut started doing research on what is now called Obstructive Sleep Apnea, and recorded breathing and sleeping patterns of a patient with Pickwickian Syndrome and discovered distinctively unique patterns of the 3 types of apneas.

Beginning in 1969 OSA (Obstructive Sleep Apnea) was often treated with a tracheostomy; bypassing the upper air passage altogether by creating an incision or opening in the trachea (windpipe) and inserting a breathing tube.

Invention of the CPAP machine

In 1981, an Australian researcher by the name of Dr. Colin Sullivan and his colleagues Berthon-Jones, Issa and Eves, introduced their findings on the treatment of OSA with something called a Continuous Positive Airway Pressure machine, or CPAP. The treatment plan started off with a reversed vacuum cleaner motor that blew air into the afflicted person's nasal passage using a Silastic tubing to keep the airway open. The initial CPAP machines were large, bulky and noisy but by the late 1980s many improvements had been made to the machine and masks and soon this became the preferred method of treatment for those who suffer from Sleep Apnea. The publishing of their research papers was a landmark development in the treatment of Sleep Apnea.

What is Sleep Apnea?

Sleep Apnea Defined

The definition of Sleep Apnea is an occurrence of some type of obstruction that temporarily stops the breathing during sleep. Apnea literally means "without breath" and these events can occur up to 30 or more times per hour of sleep. The scientific standard of an apneic event is the patient must stop breathing for at least 10 seconds per event and have an overall blood oxygen desaturation level of 3 to 4 percent along with certain potential changes in EEG frequencies and data. If a person has 5 or more of any type of events per hour of sleep then they can be clinically diagnosed with Sleep Apnea.

Initial Diagnosis

An overnight sleep study is usual indicated when seeking to diagnose if a patient is suffering from Sleep Apnea. This sleep test, usually conducted in a specialized sleep lab by a sleep doctor and a respiratory therapist, is called a polysomnogram or polysomnography test; also known as a PSG. For more on sleep studies, see our Introduction To The Sleep Lab video on YouTube.

Signs or Symptoms of Sleep Apnea

Often the people are unaware that they may have Sleep Apnea or they do not realize they have difficulty breathing in their sleep at all. It is usually someone else who witnesses the person sleeping and having these events or obstructions, usually gasping for air or a sudden stoppage of breathing while asleep, whereby they first become aware that they may have Sleep Apnea. Many people just think they do not sleep well, not realizing they have Sleep Apnea, and some try to self-medicate using sleeping pills, or alcohol to try and sleep better, which tends to make the problem worse.

Snoring is another big symptom but there are many people who snore who do not have Sleep Apnea. If snoring stops briefly and then resumes, that is a significant indicator of sleep apnea.

Daytime tiredness or drowsiness, difficulty or lack of concentration, headaches, impotence or decreased sex drive, moodiness or irritability, lack of energy, acid reflux (gastro-esophageal reflux disease aka GERD), restless sleep, tossing and turning, night sweats, memory problems, nighttime choking or chest pain, swelling of the legs in the obese, waking up foggy, groggy, or unrefreshed, anxiety, depression, increased urination at night; these could all be symptoms of Sleep Apnea. Some people first learn of the problem when they fall asleep at the wheel of a car, or are even involved in a car wreck or crash caused by the side effects of having untreated sleep apnea.

Of note, a score of 12 or higher on the Epworth Sleepiness Scale is indicative of someone who may potentially have Sleep Apnea.

Types of Sleep Apnea

(OSA) Obstructive Sleep Apnea

Obstructive Sleep Apnea is the most common form of Sleep Apnea and occurs when the muscles and tissues in the throat and air passage relax while sleeping, and this impedes the flow of air into the lungs due to a blockage of the airway. This can occur many times per hour in the sleep cycle and especially during the REM sleep stages. In REM sleep all of the muscles and in fact the entire Musculo-skeletal system goes into an extremely relaxed state that causes the tongue, soft palate, tonsils, from the nose to the glottis, and the oropharynx to completely loosen up and this creates the obstruction or impedance to the air flow, thereby causing apnea (complete stoppage) and hypopnea (partial stoppage) events, as well as snoring events.

Oxygen Saturation in the blood levels drop significantly and usually this is followed by constant neurological mechanisms or arousals with each event that may not wake the person entirely from sleep but disrupt sleep constantly enough to cause many issues. A person with Obstructive Sleep Apnea rarely gets into the REM sleep stages or restorative cycle (Slow Wave Cycle) long enough or at all and the long term effects can be quite serious and numerous.

(CSA) Central Sleep Apnea

Central Sleep Apnea is caused by the part of the brain that controls respiratory function and these centers in the brain are imbalanced and do not respond or react quickly enough to changes in oxygen or carbon-dioxide levels in the blood stream. Essentially, the brain does not respond at all to the normal triggers that would cause a person to breathe or take a breath. Pure CSA is fairly rare or uncommon. But basically the person just stops breathing for a period of time, and this can occur even when awake. A type of Central Sleep Apnea known as "Cheyne-Stokes respiration" occurs primarily in people with kidney disease, stroke, or congestive heart failure. Drops in oxygen levels (hypoxia) can cause seizures or in rare cases even death. The exact cause of Central Sleep Apnea is usually unknown and it is often partly treated with medications.

Mixed Sleep Apnea

Also called Complex Sleep Apnea, the patient has a combination of both Central Sleep Apnea and Obstructive Sleep Apnea. Treatment is usually a combination of medication and CPAP use. Advances in technology allow recently released BiPap, BiLevel and VPAP machines to treat the special needs of those with MSA.