What is Obstructive Sleep Apnea Syndrome?
Obstructive sleep apnea is the most common sleep-related breathing disorder, it is characterized by complete cessation or limited breathing for at least 10 seconds several times during sleep.
It is the condition in which the flow of air to the lungs is obstructed due to obstruction of the upper airways.
Why does this happen?
During sleep, the tissues of the mouth and throat wall relax. In some people they relax so much that the flow of air through the upper airway is blocked. In the early stages, snoring is the most notable symptom. Interruption of respiration leads to a drop in oxygen in the blood, which leads to awakening and restoration of respiration. The person, however, falls asleep again which starts a new cycle of apnea - hypoxia-awakening and so on.
Symptoms during night
- Awakenings with a feeling of suffocation
- Night urination
- Saliva hyper secretion
- Gastroesophageal regression
- Urinary incontinence
- Excessive daytime sleepiness
- Concentration difficulty
- Irritability, mood disorder
- Morning headache / nausea
- Dry mouth
Diagnosis - Sleep Study
People with obstructive sleep apnea might not be aware of their interrupted sleep, rather they seek medical help more commonly in two ways:
- They visit doctors of different specialties due to the various symptoms that arise due to OSAS.
- Visit a specialized sleep disorder center after at the suggestion of a spouse /partner.
The best and most complete method to diagnose OSAS is the polysomnography study (also called sleep study) which provides with, among other things, the apnea-hypopneaindex index (Apnea-hypopneaindex, AHI). Otherwise the patient is likely to continue treatment for many years for depression, insomnia, neurophysiological disorders without being diagnosed with OSAS. Polysomnography is a comprehenshive test and includes overnight recording of several parameters including: electroencephalogram (EEG), electromyogram (EMG), electrocardiogram (ECG), chest and abdomen movements, limb movements,oxygen blood level, air flow through the nose. It is a NECESSARY step for the diagnosis and staging of OSAS.
OSAS is associated with a number of complications:
- Cardiovascular system (stroke, myocardial infarction, unregulated hypertension)
- Nervous system
- Metabolism (insulin resistance, diabetes)
- Road accidents due to daytime sleepiness (16% of total accidents and 25% of fatal road accidents)
The main treatment of OSAS is the use of a CPAP device (Continuous Positive Airway Pressure) which maintains upper airway patency by applying positive ventilator pressure.
Types of Devices
- AUTOCPAP: continuous positive pressure ventilator, self-adjusting, recognizing the patient's pathological condition with the ability to automatically increase or decrease the pressure.
- BILEVEL: ventilation device, characterized by two levels of pressure, inhalation and exhalation. Suitable for people suffering from more serious disorders.
- AUTO – BILEVEL: an automatic ventilation device, constantly adjusts the inhalation and exhalation pressure to meet the changing needs of the patient. The device is mainly suitable for OSAS patients in whom the need for pressure changes. Suitable for patients suffering from Hypoventilation Obesity Syndrome.
What is the difference between CPAP & BiPAP
The difference in air pressure exerted on the airways and most specifically:
- CPAP is set to only one pressure level that remains constant overnight.
- However, the incoming air may make it difficult for the patient to exhale.
- BiPAP has, thus, a breathing timing feature that measures the number of breaths a person may take per minute. The device forces the person to breathe by temporarily increasing the air pressure when the time between breaths exceeds the specified limit.
- The ability to adjust different pressures for exhalation and inhalation allows the patient to move more air in and out of the lungs.
BiPAP is useful when you cannot exhale against the constant pressure of a CPAP as well as when you have a more strange breathing pattern..