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Sleep Apnea

Snoring is one of the cardinal symptoms of sleep apnea. Sleep apnea patients are frequently habitual snorers, although some snorers are not aware of their problem or the severity of the problem. An interview with the spouse or bed partner is therefore essential to elicit an accurate description. The spouse may also be able to describe the pattern of snoring and breathing. A pattern of intermittent loud snoring, interspersed with periods of silence lasting more than 10 seconds, is suggestive of the occurrence of sleep apnea.

The mere presence of an apnea itself does not necessarily indicate pathology. Short apneas of the central type are often seen during the transition between drowsiness and light sleep. In a patient with obstructive sleep apnea, the spouse may report repetitive episodes of apneas in which continued respiratory efforts are observed and choking or snorting noises.

These episodes are terminated when the patient arouses momentarily and the breathing resumes with the patient flailing and gasping for air. By convention, the presence of 5 or more episodes of apnea per hour or 30 episodes of apnea over an average night of sleep is considered to be sleep apnea.

Snoring

The gold standard for diagnosis in patients with suspected sleep apnea is polysomnography in the sleep laboratory. The following ancillary investigations may be done before the procedure. A complete blood count may reveal presence of polycythemia.

POLYSOMNOGRAPHY

The techniques for cardiopulmonary sleep studies have been described. These studies are done in suitably equipped laboratories, preferably with soundproof rooms and infrared video monitoring.

Measurement of thoracoabdominal respiratory efforts could be made by inductive plethysmography, impedance, or strain gauge devices. An esophageal balloon may be used for direct measurement.

CLINICAL PREDICTORS

Various prediction models have been proposed, based on prominent clinical indicators. It is hoped that these formulas can be used to guide rationally the decision of whether or not to pursue the diagnosis with further laboratory investigations.

TREATMENT

Indication for Treatment

Although the generally accepted criteria for diagnosis of obstructive sleep apnea is an apnea index of over 5 per hour, or apnea-plus-hypopnea index of over 15 per hour.

General Measures

It has been shown that weight loss in sleep apnea patients results in reduction in the frequency of apneic episodes during sleep. All overweight sleep apnea patients should therefore be encouraged loose weight.

Specific Therapy

In all patients, correctable anatomic obstruction of the upper airway should be looked for during physical examination. Removal of enlarged tonsils and adenoid is beneficial if they contribute to a narrowing of the oropharynx. Other patients may benefit from nasal surgery to correct septal deviation

The treatment options available fall into these major categories: (1) medications, (2) surgery, (3) dental appliances, and (4) nasal continuous positive airway pressure (CPAP). At the moment, nasal CPAP is considered to be the most effective method of treatment.

Although a number of medications have been tried, the results have been disappointing. Nevertheless, in some patients who are not tolerant of CPAP and refuse to undergo surgery, a trial with medications such as protriptyline or progesterone may be worthwhile.

The surgical options include removal of anatomic soft tissue obstruction, such as enlarged tonsils, adenoids, enlarged tongue, or nasal polyp; surgical correction of skeletal abnormalities causing micrognathia or retrognathia; conventional uvulopalatopharyngoplasty; laser-assisted uvulopalatoplasty; and tracheostomy.

All patients should have a careful examination of the upper airway, and if obvious anatomic obstruction is evident, surgical correction should be considered. Corrective surgical procedures directed at various skeletal deficiencies have been devised. One procedure involves a limited anterior sagittal mandibular osteotomy with genioglossus advancement, which creates tension on the tongue muscles and therefore limits the posterior displacement.

Dental Appliances

The usual rationale for a dental appliance is to modify the position of the mandible so as to enlarge the airway or reduce its collapsibility. Although many dental appliances of various designs have been reported to be useful in sleep apnea, these reports usually have few patient numbers and do not have adequate controls. Nevertheless, the collective data suggest a possible role for use of these devices in management of mild sleep apnea or when other therapies have been tried and found not to be successful because of problems with compliance or complications. As in all the other therapeutic options, the documentation of apnea severity before treatment and reassessment after therapy are important. Early side effects may include excessive salivation and transient discomfort on awakening. Late complications may include temporomandibular joint discomfort and occlusive malalignment.

The mechanism of action of CPAP is due to the mechanical effects of raising the intraluminal upper airway pressure. When the pressure is sufficient to counter the collapsing forces in the pharynx or hypopharynx, the airway remains patent during inspiration, and obstructive sleep apneas.