Current medical management of sleep-related breathing disorders
Sleep-disordered breathing, a disorder characterized by repeated apnea (cessation of breathing) and hypopnea (partial cessation of breathing) during sleep, has been shown to be prevalent in the general population. Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a common disorder that can adversely impact longevity and quality of life, and one in which the oral and maxillofacial surgeon possesses a unique ability to assist in managing.

Prior to offering surgical therapy, the oral and maxillofacial surgeon must have a working knowledge of medical options these patients may choose to pursue. Medical management of OSAHS requires careful clinical assessment and laboratory evaluation. Sleep-related breathing disturbances were first described in obese patients. Subsequent research has shown that obstructive sleep apnea can occur in non-obese patients as well. In fact, epidemiological data estimate that 2-5% of the population meets the criteria for OSAHS. Community based studies have confirmed that OSAHS is seen in 2% of women and 4% of men between the ages of 30 and 60 years.

OSAHS occurs when there are episodes of airway narrowing and obstruction combined with significant daytime symptoms that result from disrupted sleep. Though the basic processes causing airway narrowing are multifactorial and not completely understood, the disorder is considered to occur over a continuum of severity: the mildest form of upper airway narrowing produces rapid airflow. This rapid airflow initially causes stretching of the compliant portions of the soft tissue upper airway (i.e. the soft palate and the lateral pharyngeal walls), resulting in the soft palate elongation and eventually in snoring. Further airway narrowing results in increased upper airway resistance. This increased airway resistance is sensed by the central nervous system, causing disruption of normal sleep architecture, and forms the basis for the condition of upper airway resistance syndrome (UARS) seen most commonly in young, thin females. Further airway narrowing and frank obstruction are next on the continuum, causing obstructive sleep apnea (OSA), OSA is generally ranked on a scale of severity, based upon the number of times a given patient stops breathing over a given hour of sleep ( often called the Respiratory Disturbance Index (RDI), or Apnea-Hypopnea Index (AHI). An RDI of 0-5 events per hour is considered normal. In most clinics, an RDI of 5-20 is considered mild OSA, 20-40 or 50 is considered moderately severe OSA, and a RDI >40-50 is considered severe OSA.

Apnea is defined as a cessation of respiratory flow for at least 10 seconds accompanied by a 2-4% drop in oxygen saturation and usually an associated EEG arousal. The syndrome of obstructive breathing requires the combination of daytime symptoms, as well as an apnea-hypopnea index of at least 5 per hours of sleep. Therefore, a careful clinical history, along with the polysomnographic sleep study data, is needed. Factors that increase the risk for OSAHS include obesity, male gender (2 to 3:1 male-female ratio) as well as family history.

Nearly all patients with significant OSAHS snore, though the absence of snoring does not exclude sleep apnea. In addition, apneic episodes are reported by the bed partner in 75% of cases. As snoring can be loud and lead to restlessness during the night, it is not surprising that 46% of patients sleep apart from their partners. Bed partners may report loud snorts of vocalizations, and patients themselves note restlessness, often with associated diaphoresis in neck and upper chest. Nearly 74% of patients complain of morning dry mouth and 28% report significant nocturia (frequent nighttime urination).

Daytime sleepiness is, of course, one of the hallmarks of OSAHS. The severity of this symptom can vary from subtle to severe. Untreated sleep apnea puts patients at risk for vehicular accidents. It is common for patients with sleep apnea to report opening car windows, drinking caffeinated beverages, or chewing ice as a help to stay awake. Intellectual impairment has been noted on neuropsychiatric testing, and patients themselves may note decreased concentration and job performance.

Obstructive sleep apnea-hypopnea syndrome has been linked to hypertension. Furthermore, there is evidence that OSAHS may place patients at an increased risk for stroke. OSAHS should be looked at as yet another cardiovascular risk factor for susceptible individuals.

The decision on when, and how, to treat patients with OSAHS is complex. It must be based on clinical assessment, including physical examination, medical history and polysomnographic data. The decision must include information about a patient's sleepiness, snoring, and disruption of the bed partner's sleep as well as assessment of possible adverse cardiovascular consequences. These factors should all play a role in determining the proper therapeutic option (both surgical and non-surgical) the oral and maxillofacial surgeon offers to the patient presenting with this disorder.

Effects of medications and associated medical conditions on sleep-disordered breathing
Even moderate alcohol intoxication can decrease hypercapnic ventilatory response to 50% of baseline. Alcohol can precipitate OSA in vulnerable individuals. Older, obese subjects are more likely to be affected than are young healthy subjects. Patients with mild sleep apnea clearly develop longer and more frequent obstructive breathing events when they consume alcohol use. Therefore, an avoidance of alcohol for obese snorers and patients with obstructive sleep apnea is recommended routinely.

Smoking is widely known to impact upper airway physiology detrimentally. The combined effect of reactive conditions actually effects narrowing of the upper airway.

Sleep aids can also affect sleep and breathing and frequently prescribed. Benzodiazpeines are mild respiratory depressants like alcohol. They decrease upper airway muscle tone. It is best to avoid sedative-hypnotic agents in patients with sleep apnea. Narcotics, too, are powerful respiratory depressants are best avoided in patients with significant sleep apnea.

Hypothyroidism should also be considered in patients with a history of OSAHS. Possible mechanisms for the increase in sleep apnea seen in patients with hypothyroidism include obesity, impaired upper airway muscular function, and macromaglossia (large tongue).

Pharmacological treatment of sleep apnea has not proven effective. Pharmacological agents studied and shown not to be of benefit in treatment include progesterone, tryptophan, bactofan, and pratriptyline.

Use of supplemental oxygen, position restriction, and role of weight loss
Other forms of medical treatment for OSAHS that have been studied include supplemental oxygen. Oxygen alone is not sufficiently effective in reducing the frequency of apnea or improving daytime alertness.

Restriction of sleeping position may offer significant benefit to some patients with OSAHS. Laboratory analysis routinely breaks down the presence of sleep-disordered breathing in both the supine as well as the nonsupine positions. The supine position, with resultant occlusion of upper airway based on effects of gravity on the tongue, can result inapneic or hypopneic events. Cervical pillows, which allow one to sleep with slight extension of the head (while in the supine position), can be of benefit. Obese patients will have OSAS regardless of their position during sleep. For some patients, sleep and breathing is satisfactory in the lateral position. Use of a small ball, such as a tennis ball, pinned to the pajama back may help patients to learn behaviorally to avoid sleeping supine. In addition sleeping with the head and trunk elevated to a 30° angle reduces OSAS as it stabilizes the upper airway.

No discussion of the management of OSAHS is complete without addressing obesity. The effect of obesity on the upper airway appears to be the result of mechanical effects on the upper airway. Studies have confirmed that weight reduction can improve sleep-disordered breathing. Obese patients should always be encouraged to lose weight, but obstructive breathing must be treated while the weight loss is underway.

Use of nasal continuous positive airway pressure
Nasal continuous positive airway pressure (CPAP) is the most established therapy choice. First used in Australia in 1981, its use in America became more widespread in 1985. Nasal CPAP prevents collapse of the pharyngeal airway. CPAP successfully eliminates mixed and obstructive apneas. Titration of the pressure to levels sufficient to eliminate sleep apnea can be difficult.

Adjusting to nasal CPAP can be trying, as patients adapt both to the mask and to the pressure cessation, as well as the headgear holding the mask in place. Instructional videos, review of goals of treatment, and time in the laboratory adjusting to the device can ease transition to use.

Once correct pressure is achieved, the number of arousals triggered by the sleep-disordered breathing should be markedly reduced.

Problems related to nasal CPAP include mask discomfort, nasal congestion, and social considerations (including bed partner tolerance of the device) and chest discomfort and claustrophobia.

Nasal CPAP is effective only when the device is used, and used consistently.

Bilevel positive airway pressure
Bilevel positive airway pressure (BiPap) devices have the capability to allow for a separate pressure for inspiration and expiration. It has been shown that patients with OSA need a lower expiratory pressure than that needed to prevent upper airway occlusion during inspiration.

Back to top