What Is Sleep Apnea? Diagnosis and Treatment in Dubai

Sleep Apnea. Introduction

Sleep Apnea is the most common respiratory sleep disorder which is characterized by pauses in breathing. An apnoeic episode usually lasts 10 – 30 seconds and reoccurs several times throughout the night. The disorder affects both children and adults.

The following article describes diverse types of Sleep Apnea. It helps to identify its symptoms and to understand diagnostic approaches and currently used treatment techniques.

Types of Sleep Apnea

Obstructive Sleep Apnea (OSA)

The first and most prevalent type of apnea is the Obstructive Sleep Apnea (OSA). This type of apnea is caused by collapse of the throat muscles or by structural abnormalities of the respiratory tract. According to the National Sleep Foundation, Obstructive Sleep Apnea is the most common primary respiratory sleep disorder. It affects around 10-30% of adults. OSA is especially dominant in overweight middle-aged men but also postmenopausal women. Structural abnormalities of the respiratory system, e.g., adenotonsillar hyperplasia (overgrowth of the tonsils), is the most common OSA cause in children.

Risk factors for Obstructive Sleep Apnea (OSA)

OSA runs frequently in the families. Other risk factors are old age, obesity, and male gender. Other risk factors are family history, hormonal abnormalities, frequent alcohol use or smoking. Also, frequent alcohol use, smoking or regular intake of narcotic pain killers add to the risk.

Furthermore, OSA occurs more commonly in patients having specific anatomical features including a larger tongue, an overbite or excessive soft tissue around the neck. These features can weight down and obstruct the airway when a person is lying down.

Central Sleep Apnea (CSA)

Only about 1% of the population, presents with the second type apnea, called Central Sleep Apnea (CSA). It occurs when the drive to breathe decreases periodically or ceases, due to impaired function of the respiratory center. CSA can be classified into non – hypercapnic and hypercapnic.

Hypercapnic CSA is based on hypoventilation, triggered by central nervous system diseases like trauma or stroke. The other cause could be neurological disorders, like myasthenia gravis and chronic use of certain drugs like opioids (e.g. morphine). The non-hypercapnic type is characterized by a periodic breathing pattern which may be idiopathic (i.e. unclear rout cause) or caused by heart failure. Some patients, receiving PAP treatment for obstructive sleep apnoea, develop symptoms of central sleep apnoea. This phenomenon is called “treatment -emergent” or “complex sleep apnoea”.

Risk factors for CSA are similar to those of OSA. Additionally, patients with a previous stroke or brain tumours as well as heart disorders like atrial fibrillation are especially at risk.

Mixed Sleep Apnoea

Finally, a combination of OSA and CSA is Mixed Sleep Apnoea. It is often referred to as treatment emergent or complex sleep apnea, described earlier in the text.

Complications of Sleep Apnea

Individuals with sleep apnoea have an increased risk for cardiovascular and metabolic disorders. All types of Sleep Apnea share similar symptoms – although patients with central sleep apnoea usually do not display the same level of snoring as patients with obstructive sleep apnoea do. Sleep apnoea on its own is rarely fatal, but if undiagnosed, increases the risk for cardiovascular and metabolic disorders. Drops in oxygen levels during the apnoeic phases can trigger anginal chest pain and irritate heart cells leading to arrythmias. Hypertension, coronary artery disease, stroke and respiratory failure are also more common in apnoeic patients. Emerging data also suggests that the presence and severity of OSA and associated nocturnal hypoxemia are associated with an increased risk of diabetes type 2 and cancer.

Symptoms of sleep deprivation

The most common symptom of all apnea types is severe sleeplessness and consequently daytime fatigue and sleepiness. At night interrupted sleep can trigger nocturia and stress-induced insomnia. The effects of the disturbed sleep cycles are also apparent during the day because the loss or restful sleep leads to difficulty concentrating, morning headaches and fatigue.

Diagnosing Sleep Apnea

Diagnosing sleep apnoea requires a detailed evaluation of the patient by taking sleep history, including third-party reports. Additionally, a full overnight sleep study in a sleep laboratory is the standard test for individuals in whom sleep apnoea is considered. It usually involves getting monitored overnight with a polysomnogram (PSG). Polysomnography tracks sleep variables like brain function, oxygen and carbon dioxide blood levels, vital signs, and outward symptoms like snoring and movement.

Another variable included in a polysomnogram is the AHI is defined as the sum of apnoea’s and hypopneas per hour of sleep. Apnea is defined as the absence of airflow for ≥ 10 seconds and hypopnea as reduction in respiratory effort with ≥ 4% oxygen desaturation. An AHI of more than five events per hour of sleep is considered abnormal and the patient is suspected to have a sleep disorder. An abnormal AHI in combination with excessive daytime sleepiness is characteristic for patients with Sleep Apnea.

Treatment for Sleep Apnea

85% of individuals with sleep apnoea go undiagnosed. From those diagnosed only a low percentage gets treated. The treatment approach varies between obstructive, central and mixed sleep apnoea.

The first step in treating obstructive sleep apnoea is to adopt healthy lifestyle changes. These include losing weight, regular physical activity, quitting smoking and alcohol, avoiding sedatives and maintaining healthy sleeping habits. It is recommended to sleep on the side instead of on the back to create better airflow into the lungs. In addition to conservative treatment methods, orofacial therapy is advised. It comprises exercises that improve the position of the tongue and strengthen muscles controlling lips, upper airway and the face.

Continuous Positive Airway Pressure (PAP) Machines

The 1^st line conservative treatment for obstructive as well as central Sleep Apnea is the usage of a positive airway pressure (PAP) device. This machine forces the airways open with a stream of pressurized air delivered through a plastic facemask or nasal prongs.

There are three types of PAP devices used for Sleep Apnoea.

Continuous PAP (CPAP) provides a steady stream of pressurized air, and the amount of pressure is the same on inhalation as well as exhalation.

Bilevel PAP (BiPAP), delivers two air pressure levels, one for inhalation and another for exhalation making it easier for the patient to breath out.

Auto adjusting PAP (APAP), adjusts the air pressure level based on the patients’ breathing patterns.

CPAP devices are usually tried first in apnoeic patients but if not effective, switching to BiPAP or APAP is advised. CPAP has shown to significantly improve REM sleep phases, providing healthy, restorative sleep. Ideally, CPAP compliance should take place for as long as the patient is sleeping but, in practice, this occurs in a minority of subjects. Observational studies have shown a significant decrease in the risk for stroke and heart disease and lower blood glucose levels in patients being treated with CPAP continuously. However, based on several studies, the average compliance is only about 4h per night. Many people eventually stop using it, finding it annoying or difficult to wear, and the problem persists.

Treatment with oral appliances

Patients who are unable to tolerate CPAP treatment or suffer from a milder form of Sleep Apnoea, may benefit from oral mouthpieces, called oral appliances. Oral appliances are custom made devices that keep the airway open and can be worn at night or throughout the day, depending on the device. Mandibular repositioning or tongue retaining devices are recommended to be worn at night. A new FDA approved device, called eXciteOSA, is worn for 6 weeks 20 minutes a day. It stimulates the tongue muscle with electric impulses to strengthen and keep it from collapsing during the night.

Other treatment methods of Sleep Apnoea

In some cases, obstructive Sleep Apnoea can be managed surgically. One approach is to dilate the upper airway by removing structures like the adenoids or realigning the jawbone.

Another possibility is to cause neurostimulation of upper airway muscles by placing implants. The only FDA approved implantable device is the Inspire Upper Airway Stimulation System. IUASS is placed in the patient’s thorax monitoring during the sleep the respiration. Every time the patient tries to breathe, the device stimulates the hypoglossal nerve sending a signal to the tongue muscles. The muscles contract preventing the block of the airways.

Conclusion

To sum it up, Sleep Apnea is a common sleep disorder that often goes undiagnosed acting like a silent killer. The National Sleep Foundation reported that around 85% of the population suffering from Sleep Apnea goes undiagnosed. Such low diagnostic score may arise from nonspecific symptoms, like tiredness, or loud snoring or overweight.

In central sleep apnoea, treatment should mainly focus on the underlying disease, if present.

If CPAP treatment isn’t effective, patients with Central Sleep Apnea (CSA) may benefit from supplemental oxygen during night. If not, effective certain medications can be used in addition to restore normal breathing.

Treatment emergent sleep apnoea resolves in 98% of cases as therapy continues. In case of symptoms persistence switching from CPAP to BiPAP or APAP is recommended.

Hence, if only Sleep Apnea would be as widely known as other health problems such as cancer or high blood pressure, precisely less people would be caught unaware by this condition. Therefore, we should educate ourselves and everyone around us about sleep apnoea, it’s symptoms and possible prevention.

Useful links:

National Sleep Foundation

Standford Division of Sleep Medicine

Sleep Health