Obstructive sleep apnea (OSA) is when the upper airway is blocked during sleep. The upper airway starts at the nose and ends at the level of the trachea. By definition, an apnea is when the upper airway is blocked for at least 10 seconds in adults or 2 breath cycles in children.  The first treatment selected varies depending on the particular cause, but tends to be continuous positive airway pressure (CPAP) therapy in adults and tonsillectomy with adenoidectomy in children.

Overall, information about OSA can be hard to find and we would like to help.

This blogpost was written by physician trained in sleep medicine.

As part of the background for this blogpost, we searched the internet for frequently asked questions and answered them.

The goal of the blogpost is to educate you on what obstructive sleep apnea is.

This blogpost provides illustrations that shows the anatomy behind OSA and how it can be treated.

Disclaimer: This is an educational blog site. The content is meant for educational purposes only. There is no affiliation with any organization or company. Although we do our best to provide accurate and true information, it is possible that there may be mistakes or errors. The information is not meant to provide specific medical advice and if you rely on any information on this website, it is at your own risk. Even though the writer(s) on this blog site is/are healthcare provider(s), the information is for educational purposes only and you should consult your own healthcare provider for specific information for you. We reserve the right to update, change and manage the blog site at any point.

Woman sleeping, blocked airway, no exchange of oxygen and carbon dioxide at SnoringSchool.com
Woman sleeping, blocked airway, no exchange of oxygen and carbon dioxide. Therefore oxygen in the body can decrease and carbon dioxide can go increase.

Background information about obstructive sleep apnea:

Summary:

Obstructive sleep apnea (OSA) is when the upper airway is blocked during sleep. The upper airway starts at the nose and ends at the level of the trachea. By definition, an apnea is when the upper airway is blocked for at least 10 seconds in adults or 2 breath cycles in children.

Common areas of blockage in the upper airway include the soft palate, the adenoids, the uvula, the tonsils and the tongue. In some cases (more commonly in children), the epiglottis or supraglottis can also contribute to obstructive sleep apnea.

Adenoid faces, moderately long and narrow face viewed from the side undergoing flexible endoscopy at SnoringSchool.com
Adenoid faces, moderately long and narrow face viewed from the side undergoing flexible endoscopy.
Tonsil size grade 4 extremely large sized tonsils at SnoringSchool.com
Tonsil size grade 4 extremely large sized tonsils. Note that there is a very small airway for breathing during wakefulness and sleep.

The first treatment selected varies depending on the particular cause, but tends to be continuous positive airway pressure (CPAP) therapy in adults and tonsillectomy with adenoidectomy in children.

Scalloped Tongue crenated tongue extremely severe at SnoringSchool.com
Scalloped tongue, graded as extremely severe. Note the teeth marks which are present and are extreme, even when the patient leaves the tongue out.

Background:

Who gets obstructive sleep apnea?

Anyone can have obstructive sleep apnea. There seems to be a genetic component to it given that OSA often runs in families. There have been genetic markers that have been associated with OSA.[1, 2]

What makes someone more likely to have obstructive sleep apnea?

There are several physical features that can make someone more likely to have OSA.

First, the skeleton of the face. If the patient has a smaller lower jaw or the lower jaw is set back, then this makes it so that the tongue is farther back than it would be in a person with a lower jaw that has a normal size and position.

Second, large tonsils and adenoids. In children, OSA is commonly due to enlargement of the tonsils and adenoids. Tonsils and adenoids are tissues that help the body fight infection.

However, since similar tissue is found in other areas of the body, the removal of the tonsils and adenoids hasn’t been found to increase the risk of immune system problems.[3]

Third, a large tongue can make it more likely that a person can develop OSA. This makes sense since the tongue sits in the back of the throat, just above the vocal cords (where air enters into the trachea and then goes to the lungs).

Obesity has also been associated with OSA.

Why does obesity increase the risk of obstructive sleep apnea?

Obesity is a risk factor for OSA because the upper airway becomes narrower when a patient gains weight.

Fat deposits in the upper airway when a person gains weight. Areas that fat deposits includes the soft palate, the tongue and the walls of the throat itself (pharynx).

The fat deposits make the airway smaller, thereby making it more likely that the upper airway will become partially or completely obstructed during sleep.

How is the upper airway blocked during an apnea or a hypopnea?

There are several levels of possible obstruction during an event. The upper airway starts at the nose and ends at the mid-neck.

So, any location starting at the nostrils and ending in the mid-neck can get blocked.

Blockages or obstructions come in three main forms: 1) snoring, 2) hypopneas, and 3) apneas. 

Woman sleeping, airway blocked by the soft palate during snoring or obstructive sleep apnea at SnoringSchool.com
Woman sleeping, airway blocked by the soft palate. This can be seen in patients with snoring and/or obstructive sleep apnea.

Snoring is defined as partial airway obstruction that causes noisy breathing and the snorer may or may not have obstructive sleep apnea.

Hypopneas occur when when there is a reduction in airflow for at least 10 seconds and there is an associated reduction in oxygen.

Apneas occur when there is 90% reduction in airflow (or more) for at least 10 seconds whether it is due to a blockage of the upper airway, or it could just be that the patient is not trying to breathe.

Obstructive apnea is when the apnea event is due to an obstruction in the upper airway – the sleep study will show effort (i.e. the chest is moving), but there is no airflow at the level of the nose.

Woman sleeping, airway blocked by tongue in obstructive sleep apnea at SnoringSchool.com
Woman sleeping, airway is blocked at multiple sites. The soft palate, tongue and epiglottis are blocking the airway. This can be seen in patients with obstructive sleep apnea.

Central apnea is when the apnea event is due to the lack of any effort to breathe (i.e. the chest is not moving), therefore, there is no airflow.

Unlike the definition in adults (lack of airflow for at least 10 seconds), an apnea or hypopnea in children is when the event lasts 2 breath cycles.

What areas are commonly obstructed in the upper airway?

Common areas of blockage in the upper airway include the soft palate, the adenoids, the uvula, the tonsils and the tongue. In some cases (more commonly in children), the epiglottis or supraglottis can also contribute to obstructive sleep apnea.

How does drug induced sleep endoscopy help diagnose obstructive sleep apnea sites?

Sometimes it can be helpful for a sleep surgeon to take a patient to the operating room to evaluate the sites of obstruction during a drug induced sleep endoscopy (DISE).

During a drug induced sleep endoscopy, a patient is observed in the operating room, while they have a flexible fiberoptic endoscope in their nose.

The anesthesia provider will place an intravenous (IV) catheter and will then deliver anesthetic medications such as propofol and dexmedetomidine.

Once the patient starts obstructing his or her airway, the sleep surgeon will introduce the flexible endoscope and will note obstructions in the upper airway starting from the back of the nose, down the upper airway, to the tissue just above the vocal cords called the supraglottis.

Once the areas of obstruction have been documented, the patient will either be awakened so the surgeon can discuss the findings when the patient is seen in the clinic; or if the patient and surgeon agreed to surgeries after the drug induced sleep endoscopy procedure, then that could be performed after the DISE.

How is obstructive sleep apnea treated?

For adults, treatment will typically begin with continuous positive airway pressure therapy also known as CPAP.

In reality, however, the new machines are more sophisticated and are actually auto-titrating or auto-adjusting positive airway pressure devices (APAP).

So, what is the difference between a CPAP and an APAP machine?

Well, a CPAP machine delivers one constant pressure throughout the night, while an APAP machine delivers variable pressures throughout the night based on what your body needs.

For example, if a patient undergoes a sleep study (polysomnography) and has severe obstructive sleep apnea, then the technician may start the patient on CPAP therapy that night. If this happens, then the sleep study is called a split-night sleep study.

In a split night sleep study, the patient will wear CPAP and the technician will adjust the settings on the machine during the night in order to see what pressures work best for the patient.

Once the split-night sleep study is finalized, a pressure if often recommended.

If, the sleep study recommends a pressure of 10 centimeters of water pressure for the CPAP setting, then many providers will just write for that pressure.

However, if a patient drinks alcohol one night, then they may require higher pressures.

If the patient loses some weight, they may require lower pressures.

Therefore, many sleep physicians will prescribe a range of pressures that include the recommended pressure.

For example, if the split-night sleep study recommends a pressure of 10 centimeters of water pressure, then the sleep physician may write the prescription for 8-12 centimeters of water pressure.

It is important to keep trying to use the machine as much as possible. Although the machines can be very challenging to adjust to, many patients find that their symptoms (i.e. sleepiness, fatigue, headache) tend to improve with time.

What are alternatives to positive airway pressure therapy?

In a systematic review, in which they searched for any article on the topic, the researchers found thirty-five major treatment options that included nose treatments, palate treatments, tongue treatments, jaw repositioning treatments, and several other medical and surgical options.[4]

Woman sleeping and wearing the tongue retaining device oxygen coming into the airway at SnoringSchool.com
Woman sleeping and wearing the tongue retaining device oxygen coming into the airway. Note that the amount of airway will vary person to person.

Each of the options to treat obstructive sleep apnea targets a specific anatomical area of obstruction.

Is there any surgery that is as effective as positive airway pressure therapy as treatment for obstructive sleep apnea?

Tracheotomy is the creation of an opening between skin of the neck and the trachea (windpipe).

The temporary or permanent opening created by a tracheostomy is known as a tracheostomy.  Typically a tracheostomy tube is placed into opening in order to keep it open.

Woman upright, cuffed tracheostomy in place with labels for air moving in and air moving out at SnoringSchool.com
Woman upright, cuffed tracheostomy in place with labels for air moving in and air moving out.

Rarely, if a patient needs the tracheostomy for years and years, or permanently, then some of the tissue deep to the skin can be operated on and a permanent opening (stoma) can be created.

What are the surgeries that can be performed to treat obstructive sleep apnea?

Nose surgeries: rhinoplasty, septoplasty, sinus surgery

Palate surgeries: uvulopalatopharyngoplasty, laser assisted uvuloplasty, cautery assisted uvuloplasty, pillar implants, partial or complete uvulectomy, z-palatopharyngoplasty, lateral pharyngoplasty, transpalatal advancement pharyngoplasty

Oropharyngeal: tonsillectomy

Tonsillectomy in action. Surgeon with blue gloves on.
Tonsillectomy in action. Surgeon with blue gloves. The surgeon is using the bovie (electrocautery). Note the cutting occurs between the tonsil and the muscle.

Tongue: tongue repositioning surgeries, base of tongue reduction surgeries, non-base of tongue reduction surgeries, hypoglossal nerve stimulator placement surgeries

Epiglottis: shrink the size of the epiglottis (partial epiglottectomy), repositioning (epiglottopexy), or other epiglottis surgeries (epiglottoplasty)

Supraglottis: debulking of the supraglottis tissues

Hyoid surgery: suspension of the hyoid, or suturing of the hyoid down to the thyroid cartilage

Skeletal surgeries: maxillary advancement, mandibular advancement, maxillomandibular advancement, genioglossus advancement, sliding genioplasty (sliding the lower chin forward)

Tracheostomy: the opening that is created by a tracheotomy procedure allowing for the trachea to be connected to the skin

In children, an adenoidectomy is also performed with a tonsillectomy as standard practice.

References for obstructive sleep apnea:

1.            Varvarigou, V., et al., A review of genetic association studies of obstructive sleep apnea: field synopsis and meta-analysis. Sleep, 2011. 34(11): p. 1461-8.

2.            Xu, H., et al., A systematic review and meta-analysis of the association between serotonergic gene polymorphisms and obstructive sleep apnea syndrome. PLoS One, 2014. 9(1): p. e86460.

3.            Bitar, M.A., A. Dowli, and M. Mourad, The effect of tonsillectomy on the immune system: A systematic review and meta-analysis. Int J Pediatr Otorhinolaryngol, 2015. 79(8): p. 1184-91.

4.            Camacho, M., et al., Thirty-five alternatives to positive airway pressure therapy for obstructive sleep apnea: an overview of meta-analyses. Expert Rev Respir Med, 2018. 12(11): p. 919-929.