Medical Care:
Overview
Little evidence supports the treatment of asymptomatic patients with an RDI in the mild range. What makes this finding confusing is the independent association of snoring and morbidity. Patients with mixed apneas should be treated as if they have OSA because OSA can be life threatening and because treatment of OSA commonly abates central sleep apnea. Only healthcare professionals with adequate training in the evaluation and management of OSA should prescribe therapy for patients with SDB. CPAP should not be prescribed without PSG confirmation of the correct pressure level for CPAP because no standardized pressure value is established on the basis of age or BMI.
The primary treatment for OSA is positive pressure therapy, and nasal CPAP is the most commonly prescribed type of therapy. Other forms of positive airway pressure include bilevel positive airway pressure (BiPAP) and variable CPAP. Nightly use of CPAP for at least 4 hours is required to produce consistent ameliorative effects. Data show that compliance at 1 month is predictive of compliance at 3 months. Whether patients like CPAP depends on their perception of improvement and not on the severity of their disease, as judged by the clinician.
Variable CPAP (sometimes called auto-CPAP) is administered by using a new device whose niche has yet to be defined. The basis for variable CPAP is that the changes in pressures that a patient needs depend on factors such as body position, sleep stages, sleep deprivation, sedative use, and alcohol use, among others.
Summary of treatments
From least invasive and effective to most invasive and effective, treatments can be summarized as follows.
All patients should be offered nasal CPAP therapy first.
In patients with mild-to-severe OSA who refuse or reject nasal CPAP therapy, BiPAP should be tried next. If this therapy fails or is rejected or refused, OA therapy should be considered.
OAs may be considered first-line therapy for patients with mild OSA, particularly if they are unwilling to try nasal CPAP therapy.
All interventions to improve tolerance of CPAP therapy should be attempted prior to deciding that treatment has failed in a particular patient.
Patients in whom noninvasive medical therapy (eg, positive airway pressure, OAs) fails should be offered surgical options. Patients should be made aware of the success rates for each surgical procedure. They should be informed that they might require more than 1 surgical procedure, some fairly extensive, to cure OSA. Refer patients to only centers that have personnel experienced in these special surgical techniques.
" Nonsurgical therapy
o General and/or behavioral measures, such as weight loss and avoidance of alcohol use, sedative use, and being in the supine position, are elements of nonsurgical treatment.
o Mechanical measures include OA therapy or positive airway pressure with CPAP or BiPAP.
o Pharmacologic therapy is not part of treatment. No clinically useful drug therapy is currently available.
" Nasal CPAP therapy
o General considerations
" Initially described in 1981, nasal CPAP is currently the treatment of choice for patients with OSA and UA resistance syndrome.
" Continuous positive pressure is applied to the UA with a nasal mask, nasal pillows, or oronasal mask.
" CPAP acts as a pneumatic splint to maintain UA patency during sleep, and it is effective in the treatment of SDB.
" CPAP consists of a blower unit that produces positive-pressure airflow. This airflow usually is applied at the nose and is then directed through the UA.
" CPAP increases the caliber of the airway in the retropalatal and retroglossal regions. It increases the lateral dimensions of the UA and thins the lateral pharyngeal walls, which are thicker in patients with OSA than in people without OSA.
" Application of adequate levels of nasal CPAP during sleep almost always resolves obstructive apnea and/or hypopnea, oxyhemoglobin desaturation, and RERAs from sleep. It also results in adequate sleep continuity.
o Effectiveness
" CPAP therapy improves daytime hypersomnolence, daytime alertness, and neuropsychiatric functioning.
" CPAP improves right heart function, left heart function in patients with left ventricular dysfunction, and systemic and pulmonary hypertension.
" Patients have improved quality of life.
" Some studies report improved survival rates.
" The benefits parallel those observed after tracheostomy.
" CPAP is effective for treating mixed apneas and some central apneas.
o Compliance
" Compliance may be poor.
" Although an average of 20-40% of patients do not use the prescribed therapy, some sleep-disorder centers have achieved >90-95% compliance rates with CPAP therapy.
" In the authors' experience, regular, close, and personalized follow-up greatly enhances compliance.
o Complications and adverse effects
" Pressure- and/or airflow-related complications include a sensation of suffocation or claustrophobia, difficulty exhaling, inability to sleep, musculoskeletal chest discomfort, aerophagia, and sinus discomfort.
" Pneumothorax and/or pneumomediastinum (extremely rare), pneumoencephalos (isolated case report), and tympanic membrane rupture (rare) can occur.
" Mask-related problems include skin abrasions, rash, and conjunctivitis (due to air leaks).
" Nasal problems can include rhinorrhea, nasal congestion, epistaxis, and nasal and/or oral dryness.
" Other problems include noise and spousal intolerance.
o Guidelines for use
" Patients with severe SDB (RDI > 20-30) should be treated irrespective of their symptoms because of the increased risk of cardiovascular morbidity.
" Patients with an RDI of 5-20 should be treated if they have symptoms or coexistent cardiovascular disease. Patients with UA resistance syndrome may need CPAP therapy.
" CPAP is titrated after the diagnostic portion of a split-night protocol or on a separate night after a diagnostic PSG.
" Proper titration includes identifying the minimum CPAP level that abolishes obstructive apneas and/or hypopneas, oxyhemoglobin desaturation, RERAs, and snoring in all sleep stages and in all sleep positions. The pressure needed is typically 5-20 cm of water.
" BiPAP therapy
o In contrast to CPAP, which delivers a constant pressure during both inspiration and expiration, BiPAP permits independent adjustment of the pressures delivered during inspiration and expiration.
o The ability to set independent inspiratory positive airway pressure (IPAP) and expiratory positive airway pressure (EPAP) levels lowers mean airway pressures compared with those of CPAP.
o In a given patient, the EPAP level that must be applied is lower than the corresponding CPAP level that is required to maintain airway patency.
o No studies have conclusively demonstrated improved compliance with BiPAP devices compared with CPAP devices.
o In patients who cannot tolerate CPAP, a trial of BiPAP is warranted. However, BiPAP is too expensive to be used as first-line therapy, and it has no distinct advantages over CPAP therapy.
" OA therapy
o OAs for repositioning the mandible were first developed in the treatment of mandibular retrusion (retrognathia). Robin described an appliance, called the Monobloc device, that was used in the treatment of retrognathia. This appliance affected the patient's airway as well. Subsequent designs incorporated repositioning or advancement of the mandible.
o The first recognized appliance for the management of snoring- and sleep-related breathing disorders (SRBD) was the tongue-retaining device (TRD). This was similar to an athletic mouth guard and incorporated a pliable bulb in the front that holds the tongue forward. This bulb prevented the tongue from collapsing back into the airway during sleep.
o Mandibular repositioners later became available. These were designed for mandibular advancement. Early devices were made in 1 piece and locked the mandible in 1 position. Newer designs have separate upper and lower parts that are attached to each other and that allow for adjustability and jaw mobility. These repositioners are adjusted to advance the jaw to 60-70% of the maximum protrusion of the jaw.
o At present, 3 basic designs of OAs are used to treat SRBD: mandibular repositioners, tongue-retaining devices (TRDs), and palatal lifting devices. More than 40 OAs are available to manage SRBD and OSAS.
o OAs are believed to be effective for the following reasons:
" OAs enlarge the UA by moving (pulling) the tongue forward (ie, with a TRD) or by moving the mandible and soft palate anteriorly (ie, with a mandibular repositioner). They open or dilate the airway.
" The biomechanical factors responsible for the effectiveness of OAs are not completely understood. Increased tone of UA musculature is thought to be the predominant influence on the caliber and volume of the airway. Key among these muscles is the palatoglossus muscle. When the jaw is opened, the palatoglossus muscle (with other muscles in the pharyngeal airway) influences the airway to improve its caliber and stability.
" OAs thin the lateral pharyngeal walls by exerting traction. According to imaging studies, the size of the lateral pharyngeal fat pads and the thickness of the lateral pharyngeal muscular walls are greater in patients with apnea than in healthy subjects. For OA therapy to be successful, the lateral dimension of the airway is the critical factor.
o Most recent studies have been performed with mandibular repositioners.
o A review of the literature by the ASDA indicated the following findings:
" Overall, 51% of patients studied achieved an RDI of <10 with OA therapy.
" Of patients who had a pretreatment RDI >20, 39% continued to have an RDI above this level despite OA therapy. At least 1 randomized controlled trial demonstrated that OAs have better success rates in mild OSA (81%) than in moderate (60%) or severe (25%) OSA.
" Continuous adjustment or replacement, as needed, improves success rates with OAs in the long term.
" No patient characteristics predicted success with OA therapy.
" No particular OA had any advantages over the others studied.
" Some patients have an increase in AHI with OA treatment.
" Endpoints assessed in the studies of OAs varied and included an RDI <10, RDI <20, or a >50% reduction in the AHI. This variation made the comparison of results difficult. Furthermore, many studies did not stratify patients by severity of OSA.
" OAs were more likely to be successful in treating patients with low BMI, young age, small neck circumference, short soft palate, or small oropharynx, and in treating positional OSA, as based on retrospective data analysis.
o Subsequent prospective controlled clinical trials to compare OA therapy with nasal CPAP therapy to treat OSA and snoring demonstrated the following results:
" Treatment was successful in 55% of patients using an adjustable mandibular repositioner and in 48% of patients using a nonadjustable mandibular repositioner. Treatment success was defined as a posttreatment RDI <10, with symptomatic relief.
" CPAP therapy was superior to mandibular repositioning in normalizing the RDI, reducing snoring, and improving oxygenation.
" CPAP and adjustable mandibular repositioning equally improved daytime sleepiness.
" Most patients preferred mandibular repositioning therapy to CPAP therapy.
o Treatment success with mandibular repositioners (OAs in general) appears to be inversely related to the initial RDI. A growing body of evidence now suggests that severity of OSA is predictive of the response to OAs.
o In 1 study, OAs were more effective than UPPP in the treatment of OSA. OAs may also be useful in managing obstructive sleep apnea syndrome when surgery fails.
o The use of OAs in clinical practice is limited because of the difficulty in predicting the therapeutic response of individual patients.
" Tsai and coworkers used a remote-controlled device to titrate OA treatment during a single-night sleep study to predict the therapeutic response. In concept, this approach is similar to titrating nasal CPAP during a single-night sleep study. Raphaelson et al and Petelle and coworkers first demonstrated the titration of mandibular advancement during a sleep study. Petelle et al demonstrated that it was possible to determine the optimum level of mandibular advancement required for an individual patient during a single-night study. Of surprise, Tsai et al did not report the same.
" Apart from raising the possibility of predicting therapeutic response in individual patients, this titration approach potentially provides an opportunity to determine the optimum therapeutic dose of mandibular advancement required during a single-night sleep study.
" Further work is required in this area because it could greatly affect the use of OAs in SRBD. This research may yield the method required to identify patients who may respond to OAs and also to determine the optimum level of advancement required for an individual patient.
o The 2005 AASM practice parameters for the treatment of snoring and OSA with OAs include the following recommendations:
" The presence or absence of OSA must be determined before treatment with OAs is started to identify patients at risk because of complications of sleep apnea and to provide a baseline to establish the effectiveness of subsequent treatment.
" For patients with OSA, the desired outcome of treatment includes resolution of the clinical signs and symptoms of OSA and normalization of the patient's AHI and oxyhemoglobin saturation.
" Although OA therapy is not as effective as CPAP, OAs are indicated for use in patients with mild-to-moderate OSA who prefer OAs to CPAP, those whose condition does not respond to CPAP, those who are not appropriate candidates for CPAP, and those in whom attempted CPAP or behavioral measures (eg, weight loss, changing sleeping positions) fail.
" Patients with severe OSA should receive an initial trial of nasal CPAP because CPAP is more effective than OA therapy. UA surgery may also supersede the use of OAs in patients for whom these operations are predicted to be highly effective in treating sleep apnea.
" To ensure satisfactory therapeutic benefit from OAs, patients with OSA should undergo PSG or an attended cardiorespiratory (type 3) sleep study with the OA in place after final adjustment of fit is performed.
o According to the guidelines listed above, the major role for OA therapy appears to be the treatment of patients with mild-to-moderate OSA who cannot tolerate CPAP (and BiPAP) therapy. These devices relatively unlikely to benefit patients with severe OSA.
o Clinicians and patients prefer a titratable device, such as a mandibular repositioner because it can be adjusted to improve both effectiveness and comfort.
o Patients should receive a complete evaluation by a sleep-disorders specialist and a dental professional, both of whom should be experienced in OA therapy; their close collaboration is required.
o Follow-up PSG after final adjustment of the device is recommended to ensure that OSA is treated adequately, particularly in patients with moderate-to-severe OSA.
o OA devices may resolve snoring without adequately treating OSA.
o Complications and/or adverse effects include the following:
" Excessive salivation
" Dental misalignment with bite change
" Tooth movement
" Temporomandibular joint pain and/or discomfort (The patient should not have notable discomfort or difficulty when opening the jaw on waking in the morning.)
" Patients' objections about having an appliance in their mouth throughout the night
o The lack of long-term studies with OA may limit the clinician from choosing it as an option.
o Insurance payers may not pay for the use of OAs at this time. Check with individual insurance carriers.
Surgical Care:
AASM recommendations for surgery
Nasal CPAP is the recommended initial therapy for patients with moderate-to-severe OSA (RDI >20, lowest oxyhemoglobin saturation <85%). Patients with symptomatic mild OSA also may prefer nasal CPAP therapy.
Surgery is indicated in patients who have a specific underlying abnormality that is causing the OSA.
Surgery may be indicated if noninvasive medical therapy (nasal CPAP or OA) fails or is rejected, if the patient desires such therapy and if he or she is medically stable enough to undergo the procedure. If the patient has OSA that is moderately severe or severe (RDI >40 or lowest oxyhemoglobin saturation <80%), the patient requires perioperative airway protection with either nasal CPAP or a tracheostomy.
Surgery is indicated as initial therapy for patients with mild OSA (RDI <20, lowest oxyhemoglobin saturation >90%) if medical therapy is refused or rejected, if the patients are medically stable enough to undergo the procedure.
Obstruction
Three of 200 adults with OSA have a specific space-occupying lesion that causes an UA obstruction. Although surgical correction of such an abnormality (ie, tonsillectomy) can potentially cure OSA, most adult patients do not have such correctible lesions.
The level of obstruction in patients with SDB is classified into 3 types. Type I is obstruction in only the retropalatal region. Type II is obstruction in both the retropalatal and retrolingual regions. Type III is obstruction in only the retrolingual region.
Surgical procedures
Functional division of the pharynx into retropalatal and oropharyngeal (region posterior to the soft palate) and retrolingual and hypopharyngeal (region posterior to the vertical portion of the tongue) regions has been proposed.
Different surgical procedures have been proposed for patients with different levels of obstruction. UPPP may correct type I obstruction. Genioglossus advancement with hyoid myotomy (GAHM) may correct type III obstruction. Maxillomandibular advancement osteotomy (MMO) may correct obstruction at all levels.
Riley-Powell-Stanford surgical protocol
Because several sites of obstruction may be responsible, a systematic approach for selecting surgery has been developed. This is the Riley-Powell-Stanford surgical protocol designed in 1988. The protocol has 2 phases. Phase I consists of the UPPP and GAHM procedures, and phase II consists of the more complicated MMO procedure. Patients who are not adequately treated with phase I surgery are offered phase II surgery.
For phase I surgery, perform UPPP for patients with type I obstruction, GAHM for patients with type III obstruction, and simultaneous UPPP and GAHM for patients with type II obstruction. The overall success rate for phase I surgery is approximately 61%, although patients with severe OSA (RDI >60, lowest oxyhemoglobin saturation <70%) have a success rate of only 42%.
Phase II surgery consists of MMO, in which the jaw is advanced anteriorly. With the phased protocol, the success rate has been in excess of 90% for phase II surgery.
Postoperative care and outcomes
In some patients, tracheostomy or CPAP therapy is required in the perioperative period to ensure a safe airway.
The success of these surgical procedures depends on accurate identification of the site of obstruction in the UA. Modalities available for identifying the site of obstruction include lateral cephalometry, endoscopy, fluoroscopy, CT scanning, and MRI. The accuracy of these methods in identifying the sites of obstruction is not clear. Success rates for UPPP are only approximately 50% despite preselection of patients with type I obstruction.
Data about surgical therapy for OSA are mainly from case series. The phased protocol of Riley-Powell-Stanford holds promise for achieving cure in patients with OSA, but further data from controlled clinical trials are needed to decide its role in the overall management of OSA.
The success rates quoted are from select centers with surgeons highly skilled in these special procedures. These results cannot be extrapolated to the general population of patients with OSA. All patients undergoing surgery for treatment of OSA should undergo follow-up PSG.
" Uvulopalatopharyngoplasty
o UPPP is the most common surgical procedure performed for adults with OSA. Fujita and colleagues introduced this procedure to the United States in 1981. UPPP involves removal of the tonsils (if present), the uvula, the distal margin of the soft palate, and the redundant pharyngeal tissue, as well as reshaping of the soft tissues in the lateral pharyngeal walls.
o The surgical success rate is approximately 50% when surgical success is defined as both 50% reduction in RDI and/or apnea index (AI) and a postoperative RDI of <20 (or AI <10). This rate is despite preselection of patients with type I obstruction by using imaging and endoscopic studies. This finding highlights the inadequacy of the methods available to identify sites of UA obstruction. The outcome of UPPP is difficult to predict.
o Although the procedure usually is well tolerated and uneventful, complications can include the following:
" Pain on swallowing and pain with speech, usually for 1-2 weeks postoperatively
" Hemorrhage (2-4%)
" Swallowing difficulties, particularly regurgitation of food
" Long-term pharyngeal discomfort
" Disturbance in taste
" Numbness of tongue
" Nasopharyngeal stenosis
o Silent apnea may result. UPPP may end snoring but have no notable effect on episodes of sleep-associated obstruction. Patients have undergo postoperative PSG to rule out persistent OSA.
o AASM recommendations for UPPP are as follows: "The UPPP, with or without tonsillectomy, may be appropriate for patients with narrowing or collapse in the retropalatal region. Good preoperative evaluation does not guarantee surgical success; the effectiveness of the UPPP is variable, and the procedure should be considered when non-surgical treatment options, such as CPAP have been considered."
o Two studies showed that UPPP may make OSA worse, as it did in 31% of the patient population studied.
o Previous UPPP reduces the maximal level of pressure that patients who require CPAP therapy can tolerate. It may also compromise subsequent CPAP therapy by promoting mouth leaking.
o Uvulopalatopharyngoglossoplasty (UPPPG) is a modified UPPP with limited resection of the base of the tongue in which both the retropalatal and retrolingual regions of the UA are enlarged.
" Genioglossus advancement with hyoid myotomy
o The genioglossus muscle is repositioned anteriorly through an inferior mandibular osteotomy (genioglossus advancement). This maneuver places the pharyngeal muscles and the base of the tongue on tension and expands the airway.
o The hyoid is suspended to the superior edge of the larynx and fixed in this position, adding to the effect of genioglossus advancement.
" Maxillomandibular advancement osteotomy
o The midface, palate, and mandible are moved forward in this procedure, increasing the space behind the tongue and increasing tension on the genioglossus muscle.
o This surgery is more extensive than any of the others described. It is usually reserved for patients in whom other treatment modalities fail.
" Tracheostomy
o This procedure bypasses the UA and is the most effective surgical procedure for treatment of OSA; it is virtually 100% effective.
o Tracheostomy is unfortunately a disfiguring procedure and decreases the patient's quality of life.
o Tracheostomy is now reserved for patients with severe OSA in whom other medical and surgical treatment modalities fail. Tracheostomy also is used for airway protection during UA reconstructive surgery.
" Other surgical options
o Laser-assisted uvulopalatoplasty: Although this option successful in reducing snoring in 90% of patients, the success rate in patients with SDB is not clear. It may cause more scarring than UPPP, and it could potentially worsen apnea. Worsened OSA has been observed in the early postoperative period after laser-assisted uvulopalatoplasty. Laser-assisted uvulopalatoplasty is not recommended for treatment of OSA until further data are available.
o Laser midline glossectomy and lingualplasty: These procedures are performed to enlarge the retrolingual region by using a laser to remove a portion of the posterior aspect of the tongue. The role of these procedures in the management of SDB has yet to be defined.
o Nasal surgery: This includes septoplasty, turbinectomy, and polypectomy and may be useful as an adjunct to other procedures or to improve CPAP compliance. Nasal surgery by itself is rarely effective for the treatment of OSA.
" Radiofrequency volumetric tissue reduction of the soft palate (somnoplasty)
o Recent interest has been generated in this new technique that Powell and associates pioneered. Radiofrequency energy is used to ablate the soft palate. The US Food and Drug Administration (FDA) approve this procedure for the treatment of snoring and OSA.
o A midline soft-palate submucosal scar is created by using a needle electrode inserted near the border of the hard palate and directed toward the uvula. Pulses of radiofrequency energy are delivered, resulting in tissue necrosis and needle-tract fibrosis over subsequent weeks to months.
o A study in 22 patients with mild SDB demonstrated reduced volume of the palatal tissue and improved symptoms in all subjects. However, no data are available regarding improvement of RDI and oxyhemoglobin saturation.
" Follow-up over 12-18 months revealed that approximately 41% of patients undergoing radiofrequency volumetric reduction of the soft palate develop recurrent snoring.
" Evidence showed postsurgical improvement in the severity of esophageal pressure swings, indicating that this treatment may be useful in patients with UA resistance syndrome.
o One study of radiofrequency volumetric reduction of the soft palate in 12 patients demonstrated success in treating snoring, but data regarding adequate treatment of SDB are lacking. Data from large controlled studies are required before this technique can be recommended for the treatment of SDB. Radiofrequency volumetric reduction appears to decrease morbidity compared with UPPP, laser-assisted uvulopalatoplasty, and lingualplasty.
o Animal studies of radiofrequency volumetric reduction of the tongue have shown volume reduction in tongue tissue after treatment. Results of human studies are pending.
Diet:
" Because obesity is a major predictive factor for OSA, weight reduction reduces the risk of OSA. The best data suggest that a 10% reduction in weight leads to a 26% reduction in RDI.
" Benefits of weight reduction in patients with SDB include the following:
o Decreased RDI
o Lowered blood pressure
o Improved pulmonary function and arterial blood gas values
o Improved sleep structure and snoring
" Weight loss may reduce the optimum CPAP pressure required.
" Weight gain is one of the most important determinants of relapse of OSA after surgical treatment. Although accomplishing and maintaining weight reduction are difficult, the results are extremely beneficial when patients can do so.
" The treatment approach to SDB is not complete if weight reduction is not addressed in patients who are obese.
Activity:
" Patients should restriction their body positions during sleep.
o SDB is worsened in the supine position, and some patients have apnea only in this position.
o Preventing the patient from assuming the supine position by using devices such as a snore ball (eg, a tennis ball sewed onto the back of the patient's pajamas) or a gravity-activated position monitor may be useful. However, these devices are cumbersome and appear to benefit only patients with mild OSA.
o Patients with marked obesity may benefit from sleeping in an upright position.
o The FDA has approved a specially designed pillow (PillowPositive) for the treatment of snoring and mild OSA. This device maintains the patient's head and neck position during sleep to optimize UA patency.
" Patients should avoid drinking alcohol and using other sedatives known to make apnea worse.
" Patients should avoid smoking.
o Smoking increases the risk of snoring and apnea.
o Smoking cessation appears to decrease the risk.
o Individuals who smoke also are more likely that those who do not smoke to report problems with going to sleep, maintaining sleep, and daytime somnolence.
" Patients should avoid sleep deprivation.