There are two varieties of sleep apnea: central sleep apnea and obstructive sleep apnea (OSA). Patients with central apnea have a lack of airflow due to the absence of ventilatory effort. The center in the brain responsible for regulating breathing has a problem with sending the signal to the body. This signal disturbance then results in breathing pauses throughout the night.
OSA occurs when there is a physical blockage of the airflow in the upper respiratory track leading to the disruption of airflow to the lungs. This subsequently results in a drop in the blood oxygen level. In addition, the patient is repeatedly awoken throughout the night with each obstructive event leading to an interrupted sleep pattern and daytime hypersomnolence (daytime fatigue).
One of the hallmark signs of OSA is loud snoring with apneic events (breathing pauses). Daytime fatigue and tiredness often brings a patient in for evaluation by a physician. Morning headaches are also a common complaint. Patients who report falling asleep at work or during class or have difficulty concentrating, as well as snoring loudly, should discuss their symptoms in detail with their doctor.
OSA affects nearly 12 million Americans. In individuals ages 30 to 60, select studies have estimated that nearly 24 percent of men and 9 percent of women may suffer from sleep apnea. In addition to daytime tiredness, it has significant cardiovascular effects as well.
Fifty percent of patients with OSA have hypertension (high blood pressure). A significant amount of patients develop pulmonary hypertension which can lead to heart failure. Sleep apnea has also been implicated in impotence, decreased libido and increased risk of traffic accidents.
HOW IT'S DIAGNOSED
An overnight polysomnography (sleep study) is the gold standard in diagnosis of sleep apnea. During this study, the patient stays overnight in a monitored setting. Depending on the center, many parameters are measured which usually include an EEG, EKG, EMG, blood oxygen saturation, carbon dioxide levels.
Events where the patient stops breathing at night and oxygen levels drop are monitored and are subsequently reported back to the ordering physician. One of the main ways of assessing if a patient has sleep apnea is their AHI or RDI (a sleep number that determines how severe sleep apnea is).
The AHI (apnea hypopnea index) or RDI (respiratory distress index) is determined by the number of events occurring in an hour. An apneic event is defined as a complete cessation of breathing for 10 seconds or more and a hypopneic event is a decrease in airflow associated with a drop in blood oxygen level. The number of events is generated from the patient rsquo;s sleep study putting them in one of four categories:
Normal AHI — 0 to 5 (any number above 0 is abnormal in children)
Mild OSA — 5 to 14
Moderate OSA — 15 to 29
Severe OSA — 30 and above
There are surgical and non-surgical options to treat sleep apnea. Conservative attempts to treat OSA include weight loss, smoking cessation, exercise, and the avoidance of sedatives and alcohol at night. Obesity is a contributing factor to the severity of OSA. Even mild weight loss can aid in the treatment of sleep apnea.
Continuous positive airway pressure (CPAP) is a machine which delivers positive pressure to the patient when they breathe, opening the airway and alleviating the airway obstruction. Studies have demonstrated a decrease in cardiovascular risk and cholesterol when CPAP is tolerated greater than four hours per night. Patients also feel better rested after the use of CPAP.
Surgical options for sleep apnea are performed by an otolaryngologist head &, neck surgeon (ENT surgeon) and should be tailored specifically for each patient since no two patients are exactly alike. The aim of surgery is to alleviate upper airway obstruction.
Septoplasty and turbinate reduction open the nasal airway allowing the patient to breathe through their nose. Uvulopalatopharyngoplasty (and tonsillectomy are operative procedures that allow the physician to remove the tonsils and trim the palate. This successfully provides the patient with a larger opening to breathe. Other procedures include hyoid advancement, tongue base reduction and tracheostomy.
If you think you may have sleep apnea or are concerned about your nighttime breathing, discuss this with your primary doctor or consider seeking the assistance of an ENT surgeon or other sleep professional.
This column is provided by the Richmond County Medical Society. Dr. Ciecko is a member of the Society, with a practice in New Spingville. He specializes in otolaryngology, head and neck surgery and head and neck endocrine surgery.