Obstructive Sleep Apnea
Obstructive sleep apnea (OSA) is increasingly perceived to be a common syndrome, occurring in 2% to 4% of middle age women and men, respectively, and >20% of elderly subjects. Yet, most cases of OSA are unrecognized by the medical community. Recent data indicate increase awareness by health care providers and the public about this silent disease.

Clinical Manifestations: The two broad categories of clinical manifestations are: neuropsychiatric and cardiorespiratory.

Neuropsychiatric symptoms are the most common manifestations of obstructive sleep apnea with excessive daytime sleepiness being the most common complaint. Initially the symptom occurs while watching TV or reading a book, but as the disease progresses, memory loss, personality changes,and an increase in traffic accidents become more frequent.

Cardiorespiratory symptoms include nocturnal cardiac arrhythmias with slowing of the heart rate during the apnea episodes followed by rapid heart beats following resumption of breathing. In addition, obstructive sleep apnea has been implicated with angina, increased incidence of myocardial infarction, and mortality. Ten to 15% of OSA develop sustained pulmonary hypertension leading to right heart failure.

Diagnosis of Obstructive Sleep Apnea: The diagnosis of sleep apnea requires an overnight polysomnography. The study is conducted in a laboratory with the attendance of a technician throughout the study. During the study, sleep stages, respiratory effort, body position, electrocardiography, airflow, leg movements, and oximetry are recorded. The result of a sleep study is reported as the Apnea-Hypopnea Index (AHI). This index refers to the sum of the number of apnea and hypopnea episodes encountered during sleep divided by the number of hours of sleep. A AHI > 5 is considered abnormal.

Treatment of Obstructive Sleep Apnea: Once the diagnosis is made, treatment can be divided into general measures and specific therapy.

General Measures: These include weight loss, change in sleep position, and avoidance of alcohol and sedatives. Weight loss is recommended for all obese patients with sleep disordered breathing. Unfortunately, the goal is difficult to achieve by dietary control and more difficult to maintain. Furthermore, sleep apnea may recur despite maintenance of weight loss.

Specific Therapy: These are aimed at treating directly the obstructive events and include:

CPAP or continuous positive airway pressure is the most effective method of treatment for obstructive sleep apnea. It helps to provide a pneumatic splint to the airway during sleep preventing collapse of the pharynx. Multiple studies have shown that patients treated with CPAP have shown improvement in daytime alertness, cognitive function, and hypertension. The major problem with CPAP has been the long term compliance, dryness of the nose, rhinorrhea, and local skin irritation.

Dental appliances are of two types: mandibular advancing devices and tongue retaining devices. The indications for the use of these devices are: primary snoring, mild obstructive sleep apnea (OSA) who do not respond to general treatment, patients with moderate OSA who cannot tolerate nasal CPAP. Excessive salivation and tempomandibular joint discomfort are the most common initial complaints.

Surgical treatment includes removal of enlarged tonsils and adenoids, correction of deviated septum or removal of nasal polyps if clinically indicated. Laser assisted uvulopalatoplasty has been recently introduced as a new modality for treatment of OSA. Recent studies have shown that only half of the patients will benefit from the procedure. Tracheostomy is a last and effective modality, usually declined by the majority of patients for esthetic reasons.