Obstructive sleep apnea is the most common form of sleep apnea. It is characterized by frequent starts and stops in breathing while asleep. This type of apnea occurs when the muscles in the back of the throat relax and block the airway. These muscles help to support oral and pharyngeal structures like the tongue, uvula, soft palate, and tonsils.
When the airway is either completely or partially blocked, there is usually 10 to 20 seconds of breathing cessation, which can lower blood oxygen levels. The brain panics when this happens and rouses the body to restart breathing. Generally, this is a very brief awakening that most people do not even notice or remember. It can happen over 30 times an hour all throughout the night, which significantly disrupts restful sleep cycles.
Symptoms of Obstructive Sleep Apnea
The most obvious and common sign of this type of apnea is loud snoring.
Other signs and symptoms that may occur during the night or in the daytime include:
- Excessive sleepiness during the day, leading to difficulty with focus and concentration
- Waking up in the middle of the night short of breath
- Breathing cessation throughout the night, which is usually observed by someone else
- Dry mouth and sore throat in the morning
- Chest pain upon waking up
- Morning headaches
- Mood instability like frequent bouts of depression, anxiety, or excessive irritability
- Insomnia, problems staying asleep, and/or restless sleep
Not everyone who snores has obstructive sleep apnea. This type of snoring is extremely loud and identifiable through the long periods of deafening silence when breathing stops.
Typically, adults and children will differ in symptoms. For example, the hallmark of OSA in adults is excessive daytime sleepiness, to the point where they may fall asleep for short periods throughout regular daily activities.
Children with OSA may suffer from hyperactivity, malnutrition, and failure to thrive, which is where their growth rates are significantly reduced.
The poorer growth can happen for one of two reasons:
- The work of breathing is burning off a lot more calories.
- There is so much nasal and airway obstruction that it is difficult to swallow food and drink.
Symptoms can be present for years without the person knowing they have the disorder. Many will have issues for only a short period, with symptoms disappearing after weight loss, surgery, or other lifestyle changes. Symptoms may also be the result of a respiratory infection, congestion, throat swelling, etc.
Causes of Obstructive Sleep Apnea
In children, enlarged tonsils or adenoids most often cause OSA. Surgical removal often leads to resolution of OSA symptoms. For adults, causes may vary and include:
- Obesity, which may cause increased soft tissue around the airway
- Structural deformities that obstruct the airways
- Decrease in muscle tone, which can be caused by alcohol, substance abuse, neurological disorders, or some other underlying health conditions.
Some scientific evidence suggests that snoring for years at a time can lead to the development of lesions in the throat, just as the vibrations from snoring can lead to nerve or neuron lesions all around the body.
Women are typically less likely to suffer from OSA than men, as men in middle years are more likely to have changing anatomy in their neck and soft tissues. Women could also be at decreased risk because of the higher levels of progesterone, but they are more likely to suffer symptoms during pregnancy and after menopause.
Furthermore, there seems to be a genetic component to OSA. Studies have shown that sufferers often have a positive family history. Lifestyle factors like drinking, smoking, and overeating increase the chances of developing the condition.
Diagnosing Obstructive Sleep Apnea
OSA is diagnosed through a series of exams and tests. A thorough history and physical is taken by the primary care physician, which includes questioning how the patient is performing in daily activities and family history. The physical exam includes examining the back of the throat for any abnormalities, checking blood pressure, and measuring neck and waistlines.
Tests used to diagnose obstructive sleep apnea are polysomnography and home sleep study sleep apnea test.
Some doctors may recommend polysomnography, or in-laboratory sleep study, to be monitored overnight by a specialist who will record oxygen levels and frequency of breathing cessation or awakenings. When breathing stops, there are fluctuations in blood oxygen levels, with a subsequent increase in carbon dioxide.
In central sleep apnea, the brain sends signals to stop breathing entirely; however, in OSA, the chest will continue to move up and down to simulate inhalation/exhalation without actually breathing.
The monitors placed during the polysomnogram show chest movements are pronounced and often exaggerated in OSA patients.
There are one of two events characterized on this study:
- Apnea, which is when airflow is completely blocked and breathing stops for at least 10 seconds
- Hypopnea, which is when airflow is 50% decreased for at least 10 seconds, or there is a 30% decrease in airflow with a subsequent awakening or serious drop in oxygen saturation levels.
Home Sleep Test
Many doctors are starting to use home sleep studies, which are much more convenient and comfortable for the patient. This is a noninvasive way of monitoring blood oxygen saturation levels during sleep.
Patients who are at higher risk of OSA are first given the STOP BANG questionnaire or other sleep apnea screening questionnaire, and a significant score means they likely have OSA rather than another sleep disorder.
Unfortunately, home oximetry does not measure apnea events or arousals, so it could be difficult to diagnose OSA with a home oximeter.
Treatments for Obstructive Sleep Apnea
The first line of treatment for OSA is always lifestyle changes. Reducing alcohol intake, losing weight, quitting smoking, and avoiding sedative medications are a starting point for treating physicians. However, lifestyle modifications do not always resolve the issues; therefore, one or more of the below options are considered in treatment plans.
Next to lifestyle changes, continuous positive airway pressure (CPAP) treatment is the frontline of treatment. It is most effective for moderate to severe symptoms. This resembles, but is different from, a ventilator. A facemask is attached to a tube that is connected to a machine, which continuously pushes positive airway pressure into the breathing passages. This helps to keep the airways open.
Variable positive airway pressure, also known as BPAP, is another type of ventilation, but instead of continuous airway pressure, the machine uses a circuit to monitor breathing and provide two different pressures: one for inhalation and one for exhalation. The inhalation pressure is higher than the exhalation pressure. This treatment is more common in patients with serious respiratory conditions.
This bandage-type device is placed over the nostrils to enhance the person’s regular breathing cycles, create positive airway pressure, and prevent obstruction. This is a device commonly used in mild cases of OSA.
Sleep Apnea Oral Appliance
Splints or other oral appliances are sometimes used in conjunction with other treatments. Patients often prefer them because they are less “invasive” than CPAP, but sometimes they do not work as well. These splints are mouth guards that keep the passages open and protect the teeth and gums. It holds the lower jaw down and forward to keep it in a more forward position, while simultaneously holding the tongue further away from the airway.
Sleep Apnea Surgery
Sometimes, modifying airway anatomy is necessary to treat OSA symptoms. These types of surgeries will vary depending on the cause of the condition and the patient’s anatomy. The various operative procedures include:
- Tonsillectomy and adenoidectomy
- Nasal surgery such as turbinectomy or straightening a deviated septum
- Reduction or removal of uvula or soft palate
- Reduction of the size of the tongue base
- A procedure that surgically moves the jaw forward, pulling the tongue away from the back of the throat (genioglossus advancement)
- Hyoid suspension, where one of the neck bones is pulled forward
- Bariatric surgery for morbidly obese patients
This option is used for patients who cannot tolerate the CPAP machine. This system senses respirations and stimulates the hypoglossal nerve with electrical currents to increase muscle tone, which will help avoid the tongue collapsing to the back of the throat and blocking the airway.
What is the Prognosis for Patients with OSA
The apneic and hypopneic events associated with OSA cause a fight or flight response in the body, which further creates a hormonal reaction. Excessive use of this response can put an undue amount of stress on the body, exhausting the glands and organs that are activated during the fight or flight response. This, paired with consistently low oxygen saturation levels, can lead to long-term dangerous health consequences.
If the above symptoms become so severe that daily activities and work are affected, then it’s time to seek medical attention. Untreated obstructive sleep apnea can lead to long-term serious conditions such as:
- Cardiovascular disease
- Daytime fatigue, which can be hazardous in school or work environments and driving
- Eye and vision problems
- Mood and psychiatric disorders
One of the most serious concerns of untreated OSA is cardiovascular disease. Sleep apnea patients are at 30% higher risk of heart attack and heart-related death than those without the condition. Increased pulmonary pressures to the right side of the heart, a major concern in prolonged cases of OSA, can result in cor pulmonale, a very serious and dangerous form of congestive heart failure.
Obstructive sleep apnea and very loud snoring may seem harmless at first, but it can lead to a laundry list of daytime symptoms and more serious and extensive health concerns, so diagnosis and monitoring should be a priority.
- Obstructive sleep apnea. (n.d.). Retrieved July 25, 2016, from https://en.wikipedia.org/wiki/Obstructive_sleep_apnea
- Mayo Clinical Staff. (2016). Obstructive sleep apnea. Retrieved July 25, 2016, from http://www.mayoclinic.org/diseases-conditions/obstructive-sleep-apnea/home/ovc-20205684