Introduction

Obstructive sleep apnea (OSA) is a disorder whereby the upper airways becomes obstructed when one is asleep. It is the most common breathing disorder experienced during sleep. OSA is characterized by prolonged partial or complete disruption of breathing.

One might stop breathing for a short period, which can last for up to 10 seconds. This disruption of breathing happens several times throughout the night. Hence, the person’s sleep patterns are disrupted, and the sleep quality is reduced significantly. Many patients report excessive daytime sleepiness as a result of insufficient sleep during the night caused by the condition. OSA is caused by the collapse of the pharyngeal airway, which leads to obstruction of the airway. It is associated with many health conditions, including obesity, hypertension, hypoxia, diabetes, hypercarbia, atrial fibrillation, and cardiovascular disease. The condition can be treated and resolved permanently.

Types of Obstructive Sleep Apnea

OSA is categorized into three levels based on severity:

  1. Mild – the individual has less than 14 episodes of breathing obstructions in an hour.
  2. Moderate – The individual has between 15 to 30 breathing obstructions episodes per hour.
  3. Severe – The person’s sleep is interrupted more than 30 times per hour.

Symptoms

The main characteristic of sleep apnea is the frequent interruption of breathing when asleep. The person’s breathing stops repeatedly during the night for short periods or intervals. The individual also shows other symptoms, including:

  • Snoring
  • Gasping for air
  • Choking
  • Fatigue
  • Hypertension
  • Snorting
  • Irritability
  • Dry mouth
  • Morning headache

In OSA, one experiences repeated obstruction of the upper airway when asleep. This obstruction leads to a reduction in the oxygen levels in the blood and an increase in carbon dioxide levels. When the episode ends, the individual can wake up abruptly while choking and gasping for air. Sleep fragmentation occurs and the central nervous system (CNS) gets activated. This disruption of sleep and unusual activation of the CNS lead to conditions such as:

1. Insomnia

Insomnia is a difficulty in falling asleep or maintaining sleep throughout the night. One can stay in bed for long before sleep onset, wake up too early, or lose sleep at night. Insomnia can be distressing to the individual and lead to difficulties in performing daily tasks and ultimately affecting one’s quality of life. One is considered to have an insomnia disorder if the symptoms persist for over three months.

2. Excessive daytime sleepiness

An individual who has excessive daytime sleepiness often requires frequent naps during the day due to nighttime sleep deprivation. The person will also have low energy, poor concentration, and appear fatigued throughout the day. Their normal function is affected because they feel drowsy most of the time. Performing tasks, such as driving and operating heavy machinery, can be dangerous when an individual is dealing with excessive daytime sleepiness. The individual’s quality of life is reduced significantly.

Causes

OSA is caused by the narrowing or closure of the upper airways thus preventing the flow of air into the lungs. The sites that cause the obstruction are:

  • Velopharynx
  • Oropharynx
  • Hypopharynx

The collapse of these airways depends on different factors, including:

  • The underlying neuromuscular tone
  • The synchronization of the upper airway muscles
  • The stage of sleep

OSA is also influenced by other health conditions such as:

1. Atrial fibrillation

Atrial fibrillation is a cardiovascular condition in which an individual has an abnormal heart rhythm. The heart beats at an irregular rate, which is often abnormally rapid. A large number of patients who have atrial fibrillation have obstructive sleep apnea. The occurrence of OSA and atrial fibrillation is associated with obesity and cardiovascular diseases.

2. Obesity

Obesity has been recognized as a global epidemic that leads to many health complications, including obstructive sleep apnea. Over 40% of individuals who are obese suffer from obstructive sleep apnea because they have a lot of adipose tissue around the neck, which causes the narrowing of the airway. The prevalence of OSA increases with an increase in BMI.

3. Down syndrome

Individuals with the Down syndrome are at a high risk of experiencing obstructive sleep apnea. OSA is thought to cause the unusual pulmonary hypertension that is reported in many down syndrome cases.

Risk factors

Several factors put an individual at risk of obstructive sleep apnea, including:

1. Genetics

The size of the airway can be influenced by genetic factors. The craniofacial characteristics and ventilator control mechanisms, which influence the breathing of a person when asleep, are inherited. Abnormalities in these features lead to obstructive sleep apnea, which can run in the family.

2. Age

Obstructive sleep apnea is prevalent in individuals who are older than 40. The natural aging process causes the muscles around the airway to relax as they lose their integrity. The tissues around the airway collapse and obstruct the flow of air into the body causing the condition.

3. Gender

Cases of obstructive sleep apnea are more common in men than in women. It is hypothesized that the descent of larynx, which leads to deeper voice in men, also causes their airways to become more vulnerable to obstructive sleep apnea than women.

Diagnosis

Early identification of obstructive sleep apnea is important because the condition can lead to other medical conditions, including excessive daytime sleepiness, cardiovascular diseases, and insomnia. Obstructive sleep apnea can also lead to challenges during medical procedures, such as the use of anesthesia when carrying out surgeries. Post-operation complications are also high in individuals who undergo surgery before obstructive sleep apnea has been identified.

In the diagnosis of obstructive sleep apnea, most of the information is obtained from other people other than the patient, such as family, sibling and spouse. The symptoms of the condition, such as snoring, only occur when the person is asleep.  Close ones can observe these symptoms and explain them to a doctor. The diagnosis of obstructive sleep apnea can be challenging in some cases because of its close resemblance to other sleep disorders that are related to breathing. Several methods can be used to diagnose obstructive sleep apnea, including:

1. Medical history review

Reviewing a patient’s medical history helps the doctor identify health conditions that may be linked to obstructive sleep apnea. This condition is associated with many health complications, including obesity, cardiovascular disease, Down syndrome, and atrial fibrillation. Identifying and treating the underlying health condition eliminates obstructive sleep apnea in most cases. The doctor analyses the patient’s previous and present health conditions that can be contributing to the occurrence of obstructive sleep apnea symptoms.

2. Clinical examination

The doctor analyses different physical characteristics that can indicate the presence of obstructive sleep apnea. These features affect the function of the upper airway when the person is asleep. Abnormalities in the airway, such as enlarged tonsils, prevent the flow of air into the body causing sleep apnea. Craniofacial abnormalities are examined using a cephalometric radiograph, while the tissues in the airway are analyzed through magnetic resonance imaging. The weight of an individual also plays a major role in the occurrence of obstructive sleep apnea. Characteristics such as an increased body mass index and a large neck circumference, which are present in cases of obesity, can point towards obstructive sleep apnea.

3. Sleep study

Polysomnography is a common sleep study in which the different elements of sleep are analyzed. The patient undergoes an overnight sleep study in the laboratory or at home. The brain waves, heart rate, breathing rhythm, and muscle activity of the individual while asleep are recorded. The information obtained from polysomnography is used by the doctor in diagnosis.

4. Questionnaires

Questionnaires are given to the patient and close ones (family, siblings or spouse) to obtain information on the sleep habits that might indicate the presence of obstructive sleep apnea. Many questionnaires have been developed for diagnosing sleep breathing disorders. The Brouilette questionnaire is the most commonly used one because it is highly specific, effective, and has been validated for use in identifying obstructive sleep apnea. The questionnaire contains questions about many factors related to obstructive sleep apnea including:

  • Snoring
  • daytime sleepiness
  • history of hypertension
  • age
  • gender
  • Height
  • Weight
  • Neck circumference

A positive diagnosis of obstructive sleep apnea is made when the patient is found to have persistent snoring, daytime sleepiness during routine activities or work, a history of hypertension, and a high body mass index.

Treatment

Obstructive sleep apnea should be treated immediately after a positive diagnosis because the condition increases the risk of many health problems, including hypertension, dysrhythmias, heart failure, myocardial infarction, and stroke. The mortality rate is also high in cases of obstructive sleep apnea because of its association with cardiovascular complications.  The common treatment methods for obstructive sleep apnea include:

1. Continuous Positive Airway Pressure (CPAP)

CPAP is the most common method of treatment for obstructive sleep apnea. It involves delivering continuous positive airway pressure through a mask that covers the nose and the mouth when the person is asleep. The pressure keeps the airway open throughout the night. The amount of pressure required for every individual is different and, therefore, it should be determined in the laboratory or by a doctor before using the CPAP machine. This method is effective in treating obstructive sleep apnea and eliminating its symptoms. Patients report easier breathing during the night, improved sleep quality, and reduced daytime sleepiness.

2. Surgery

Surgery is an effective method of resolving obstructive sleep apnea permanently. It should be considered as a last resort when CPAP and other treatment options have proven to be ineffective. Surgery can lead to other complications due to the invasive nature surgical procedures require, such procedures involve correcting the physical abnormalities that influence the condition. Different surgical procedures can be used to treat obstructive sleep apnea, including:

a. Palatal Surgery

This surgery is carried out to modify the specific site on the upper airways that restricts the flow of air. The most common palatal surgery procedure is uvulopalatopharyngoplasty that involves removing the tissues around the throat that compress the airway and restrict airflow. This method is effective in treating obstructive sleep apnea in over fifty percent of all cases.

b. Maxillofacial surgery

These are procedures that are used to change the abnormalities in the facial muscles and bones that interfere with a person’s breathing. The procedure usually eliminates obstructions around the tongue, and it is commonly performed together with uvulopalatopharyngoplasty. A maxillomandibular advancement can be performed in cases where the jaw’s natural alignment is found to affect one’s breathing. The jaws is pushed forward to give the airway enough space, thus, preventing airflow resistance.

3. Nasal dilators

Nasal dilators are devices used to reduce the resistance of airflow through the nose when asleep. They make breathing easier and enable a sufficient supply of oxygen in the body. The size of the nostrils commonly affects the flow of air, whereby, a narrow nostril reduces the amount of air that gets into the body. The collapse of the tissues in the nasal walls also reduces the available space for the movement of air. Nasal dilators are used to increase the size of the airway and prevent the walls from collapsing. They are commonly in the form of strips that are placed externally on the nose. They cause the blood vessels in the nose to shrink and stiffen the walls of the nose to prevent them from collapsing. The nasal airways are, therefore, enlarged and resistance is reduced. Internal dilators can also be used, and they work by lifting the tissues in the nose to open up the nostrils. The effect of nasal dilators is temporary; thus, they are used repeatedly.

4. Drugs

Treating obstructive sleep apnea using drugs has not been very effective. The treatments used for other breathing disorders, such as benzodiazepines, tend to worsen obstructive sleep apnea and are, therefore, not recommended. Few medications have had success in managing obstructive sleep apnea, including Protriptyline and fluoxetine. These medications are effective in managing obstructive sleep apnea in mild cases but are not helpful in severe cases.

5. Lifestyle changes

obstructive sleep apnea can also be managed by changing one’s lifestyle habits, including:

1. Weight loss

Losing weight can be beneficial in reducing the symptoms of sleep apnea as it is mainly associated with obesity. Excess adipose tissues around the neck due to obesity compress the airway and obstructs breathing. Exercising regularly and eating healthy foods can help one to lose weight, thus eliminating obstructive sleep apnea.

2. Quitting smoking

Smoking can irritate the airway and aggravate obstructive sleep apnea. The nasal passages can get inflamed due to the smoke, thus restricting the flow of air into the body. Therefore, quitting smoking can alleviate the symptoms of obstructive sleep apnea and improve one’s airflow.

3. Finding a proper sleep position

The symptoms of obstructive sleep apnea can be influenced by one’s sleeping position. Sleeping on the back causes the tongue to fall back, thus blocking the movement of air in and out of the lungs. Sleeping on the side can reduce this incidence and help the person to breath effortlessly through the night.

Conclusion

obstructive sleep apnea is a common breathing disorder that occurs in one’s sleep. It is caused by the restriction of airflow repeatedly during the night. An individual ceases breathing for a short period on several occasions throughout their sleep. The person snores, gasps, snorts, and chokes in their sleep several times as the breathing stops and resumes several times. Obstructive sleep apnea has different symptoms including daytime sleepiness, insomnia, hypertension, dry mouth, morning headache, and irritability. It is also associated with other health conditions, including atrial fibrillation and Down syndrome. The risk factors of obstructive sleep apnea include excess weight, old age, male gender, and a family history of the condition. Obstructive sleep apnea is diagnosed by reviewing one’s medical history, an overnight sleep study, a thorough clinical examination, and questionnaires. The condition is mainly treated using positive airway pressure, which is effective in keeping the airway open throughout the night. Nasal dilators are also used to keep the nasal passages open temporarily. In severe cases, surgery is carried out to eliminate the abnormalities that restrict the flow of air into the body.