Obstructive sleep apnea syndrome, part 2: Reviewing the treatment choices

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is a common form of sleep-disordered breathing. Although OSAHS frequently escapes detection, there are some well-defined risk factors, such as obesity, certain upper airway configurations, a large neck circumference, and hypertension, that serve as "red flags" to the diagnosis. Reports of excessive daytime sleepiness or sudden choking arousals from sleep are other clues to possible OSAHS.

Since OSAHS can have serious consequences, including accidents resulting from excessive daytime sleepiness and increased risk of cardiovascular morbidity, prompt recognition and appropriate treatment are crucial. In the April 2006 issue of The Journal of Respiratory Diseases, we presented our approach to the diagnosis of OSAHS. In this article, we will discuss available treatment options, including lifestyle modifications and continuous positive airway pressure (CPAP).

LIFESTYLE CHANGES

The successful management of OSAHS requires patient education about the disorder and rationale for treatment, a thorough discussion of treatment options, appropriately timed follow-up, and flexibility in the event of problems. Treatment decisions should be based not only on the patient's apnea-hypopnea index (AHI) but also on symptoms, comorbidities, and psychosocial factors. In general, lifestyle modifications alone are sufficient only in patients with mild OSAHS.

All patients with OSAHS should be counseled on implementing conservative measures, such as weight loss, moderation of alcohol consumption, smoking cessation, nasal decongestion, and avoidance of sleep deprivation. One study indicated that a 10% weight loss predicted a 26% decrease in the AHI.¹ A meta-analysis concluded that bariatric surgery resolved or improved OSAHS in 84% of patients.²

For patients who have OSAHS associated with sleeping supine, one technique to avoid sleeping on their back is to sleep in a snug nightshirt with a few tennis balls tucked in along the spine.There is no evidence to support the efficacy of external nasal dilator strips, internal nasal dilators, or oronasal lubricants in patients who have OSAHS.³

CPAP THERAPY

The mainstay of OSAHS therapy is CPAP. A CPAP system consists of a blower that delivers a constant or variable (autotitrating) pressure; a tight-sealing nasal, oronasal, or oral interface; and a flexible tube connecting the mask to the blower. Additional features include a humidifier; a pressure ramp, which allows the blower to gradually reach the target pressure over a preset time period; and a downloadable compliance monitor. CPAP devices are portable and can be adapted for use outside of the traditional bedroom setting and in other countries when traveling.

The Centers for Medicaid and Medicare Services will cover CPAP costs when the patient's AHI is 15 or higher or when the AHI is 5 to 14 and the patient has symptoms of excessive sleepiness, impaired cognition, mood disorders, or insomnia or has documented hypertension, ischemic heart disease, or history of stroke.

Method

CPAP is titrated by the technologist during polysomnography. The goal is to eliminate apneas, hypopneas, respiratory effort-related arousals, and snoring--ideally, even during the vulnerable period of rapid eye movement sleep in the supine position. For most patients, the required pressure is 7 to 11 cm H₂O.

Autotitrating CPAP devices use manufacturer-specific algorithms to provide the circumstance-specific pressure within a range set by the prescriber. These systems decrease the AHI as effectively as standard CPAP at slightly lower mean pressures throughout the night, but they produce only a modest increase in compliance.⁴ Initiating autotitrating CPAP therapy in patients who have not undergone polysomnography is not an established practice.⁵

Compliance issues

CPAP has been demonstrated to produce symptomatic and cardiovascular improvements and reduce hospitalizations for cardiopulmonary disease.^6-9 However, it can be cumbersome to use, and clinical experience suggests that 20% to 40% or more of patients fail to use it regularly.

The patient's early pattern of CPAP use predicts long-term compliance, emphasizing the need for proper introduction and prompt follow-up.¹⁰ Strategies that promote compliance include demonstrating the CPAP technique before the patient has polysomnography, individualizing the fit of the mask, and including the patient's partner in the CPAP orientation session.¹¹

^{At our facility, after polysomnography we offer patients written information about CPAP, a 1-month follow-up, on-demand telephone access to nurse specialists who answer questions, and annual rechecks. At the annual rechecks, the patient's weight and blood pressure are measured, the CPAP equipment is checked (and troubleshooting is done), adherence to therapy is assessed, and the patient is asked about symptoms that might suggest reemergent OSAHS (such as breakthrough snoring and daytime sleepiness) and about the development of other sleep problems (such as insomnia and restless legs).}

^{Patients may also turn to their primary care provider for CPAP monitoring and troubleshooting. A directed approach allows CPAP therapy to be assessed, even within the confines of a brief office visit.}

Follow-up

Patients (and, preferably, their partners) should be asked whether any snoring occurs during CPAP use. The presence of such breakthrough snoring suggests one of the following problems:

• The CPAP level needs to be adjusted upward.

• The nasal interface may be situated incorrectly when the patient is sleeping.

• The equipment needs to be checked. The blower should be checked at least annually, and the nasal interface should be checked or replaced every 6 months.

The recurrence of any of the symptoms of OSAHS, such as excessive daytime sleepiness, may be the result of noncompliance, technical problems, improper pressure, inadequate sleep hygiene, or other sleep disorders (Table 1). The CPAP level may need to be adjusted because the original titration was inaccurate or because the patient has gained weight or is drinking alcohol before going to bed (weight gain and alcohol use can negate the original pressure determination).

For this reason, it is prudent to monitor the patient's weight. We use a gain (or loss) of 10% or more as a trigger consider empiric increases (or decreases) in pressure. Ask patients who have gained weight about breakthrough symptoms and consider using overnight oximetry to assess the adequacy of the pressure.

The routine use of a bilevel positive airway pressure device has not been shown to improve com- pliance in patients, but it may be an option for those in whom CPAP therapy has failed. Heated humidification may improve CPAP compliance; patients who are likely to benefit include those who are older than 60 years, have chronic nasal mucosal diseases, use nasal drying medications, or have undergone uvulopalatopharyngoplasty.¹²

If the patient is having difficulty with CPAP, reevaluation by a sleep medicine specialist should be considered before CPAP is abandoned. Also consider referral to a specialist if the patient's weight has changed by more than 10%; if the patient is planning to undergo surgery; or if you are considering other OSAHS treatment options, such as an oral appliance or upper airway surgery.

ORAL APPLIANCES

These appliances can relieve pharyngeal obstruction by mechanically enlarging or stabilizing the upper airway by advancing the mandible (typically, to 50% to 75% of maximal protrusion) or tongue.¹³ Snoring is subjectively improved in most patients using oral appliances. Patients usually prefer oral appliances to CPAP, and patient- reported compliance rates are 75% to 90%.¹³ However, compared with CPAP, oral appliances are less effective at reducing the AHI; about 50% of patients achieve an AHI of less than 10.¹³

The advantages of oral appliances include increased portability and less obtrusiveness compared with CPAP. The disadvantages include oral soreness, excessive salivation, and a temporary change in morning dental occlusion. Like CPAP, oral appliances can become inadvertently displaced during sleep.

Close collaboration with a dentist is necessary for patient selection and for titration of the device. Patients need to have a sufficient number of teeth to anchor the oral appliance, and they must be free of active dental disease and temporomandibular joint problems.

Clinical predictors of a positive outcome with oral appliances include younger age, lower body mass index, smaller neck size, positional OSAHS, and lower AHI.¹³ Therefore, oral appliances are indicated in patients with mild to moderate OSAHS. However, they may also be helpful for patients with moderate to severe OSAHS who are unable or unwilling to consider other treatment options.¹⁴

UPPER AIRWAY SURGERY

A variety of surgical options exist to relieve upper airway obstruction in patients with OSAHS (Table 2). These interventions are sometimes applied sequentially to the suspected site(s) of obstruction or are combined with other OSAHS treatment modalities. Because it is difficult to accurately determine the site(s) of upper airway obstruction, predicting the outcome of these interventions is challenging. This underscores the importance of postsurgical follow-up.

With the exception of patients who need tracheostomy or maxillomandibular advancement, candidates for surgery typically have milder OSAHS or obvious craniofacial abnormalities. Surgical options include^15-18:

• Tracheostomy.

• Uvulopalatopharyngoplasty.

• Laser-assisted uvulopalatoplasty.

• Radiofrequency ablation.

• Nasal procedures.

• Mandibular osteotomy with genioglossus advancement and hyoid myotomy and suspension.

• Maxillomandibular advancement.

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