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Minnesota Health Technology Advisory Committee. Minnesota Health Technology Assessments [Internet]. St. Paul (MN): Minnesota Department of Health; 1995-2001.

  • This publication is provided for historical reference only and the information may be out of date.

This publication is provided for historical reference only and the information may be out of date.

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Treatment of Obstructive Sleep Apnea in Adults

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Executive Summary

This assessment outlines diagnostic and treatment options for obstructive sleep apnea (OSA), the most common type of sleep-disordered breathing.Information provided in this assessment is limited to OSA in adults and should not be applied to a pediatric population.

Findings and Conclusions

Data Quality

  • Little comparative or generalizable patient outcome data on diagnostic and treatment methods for OSA in adults are available.
  • Evidence in the medical literature shows that diagnosis and treatment of OSA in adults vary greatly between facilities. Interpretation of data was limited due to small study size and lack of controls or randomization of many studies.
  • Few cost-effectiveness analyses on any of the diagnostic methods or OSA treatment were identified in a search of the medical literature.

Diagnosis

  • OSA is a complex condition which may be exacerbated or relieved by a number of physical and physiological factors. As a result, particular attention must be paid to informing patients on what is and is not known about the effectiveness of diagnosis and treatment strategies for OSA.
  • Professional groups recommend that patients with suspected OSA undergo a complete physical and otolaryngologic examination including medical history and determination of body mass index (BMI).
  • Overnight polysomnography (PSG) is considered the gold standard of sleep apnea diagnosis. There is controversy, however, on whether the costs of overnight PSG provide substantially better diagnostic information compared to alternatives such as in-home sleep studies.

Oversight of Sleep Laboratories

  • Although the American Academy of Sleep Medicine (AASM), formerly the American Sleep Disorders Association (ASDA), accredits sleep laboratories and centers, there is no centralized oversight of sleep facilities. A clinic, hospital, or other facility may establish a sleep disorders program with no review or oversight by a professional group. Thus, determining the quality and standard of care of a particular program is difficult for professionals and even more difficult for patients.

Treatment Selection

  • Guidelines for diagnosis and treatment of OSA in adults have been developed by several professional organizations; however, there is no clear consensus on patient selection criteria for sleep studies and treatment options.
  • Selection of treatment(s) for individual OSA patients should be based upon balanced consideration of disease severity and site(s) of obstruction, subjective symptoms, risks of morbidity and mortality, and patient choice.
  • Treatment effectiveness is variable and dependent on patient needs. It is believed that treatment must be evaluated over time for good patient outcome.

Medical and Behavioral Treatments

  • Several medical and behavioral treatments for OSA in adults are available including change in sleeping position, drug therapies, and use of dental devices. This assessment focuses on two approaches - weight reduction and nCPAP.
  • Data in the literature indicate that weight loss in obese adults may be associated with improvements in the objective and subjective signs of OSA; however, many patients return to obese body weight over time.
  • For patients who are inappropriate candidates for behavioral treatments, nCPAP is the mainstay of therapy. Compliance rates are variable due to discomfort and side effects of nCPAP. Compliance is highest among patients who experience improvement in levels of sleepiness, alertness, and other daytime symptoms.

Surgical Treatments

  • Surgery may be appropriate for patients who cannot comply with or are not appropriate candidates for conservative therapies or nCPAP alone. The type of surgery performed should be based upon the specific pathophysiology of a patient's condition.
  • Careful and thorough preoperative examination by radiography, imaging, and direct visualization is needed to identify the airway obstruction site(s) and to select the appropriate surgery.
  • Uvulopalatopharyngoplasty (UPPP) is most efficacious for patients with oropharyngeal obstruction. The failure rate increases when it is performed alone in the presence of retrolingual obstruction. Response rates to UPPP decrease over time.
  • When patients have multiple sites of obstruction or craniofacial skeletal abnormalities, UPPP combined with mandibular osteotomy with genioglossus advancement and hyoid myotomy (GAHM), or mandibular osteotomy with maxillomandibular osteotomy and advancement (MMO), or MMO alone, are more effective than UPPP alone for decreasing the respiratory disturbance index (RDI), excessive daytime somnolence (EDS), and snoring.
  • The efficacy of midline glossectomy (MLG) following failed UPPP is relatively low and is variably affected by body weight and OSA severity; the long-term outcome after MLG is unknown.
  • While data indicates laser-assisted uvulopalatoplasty (LAUP) can improve snoring and EDS, no evidence based guidelines suggest LAUP is effective or safe as a treatment for OSA.
  • Tracheostomy is an effective treatment for OSA. Use of this procedure is limited to patients for whom other treatment options have failed due to associated morbidity and negative cosmetic effects.

Recommendations

Based upon the conclusions outlined above, the Health Technology Advisory Committee recommends:

  1. The presence and extent of OSA in adults must be documented by established methods including clinical examination and additional diagnostic procedures including PSG, if necessary. Conditions that may exacerbate OSA must be treated.
  2. In uncomplicated, nonemergent cases, first-line treatment options should include conservative measures such as reduction of alcohol or sedative use, sleeping in the lateral position, and weight loss if the patient is overweight.
  3. In clinically significant OSA, nCPAP is the treatment of choice and should be pursued prior to consideration of surgical therapies.
  4. Patients who may be candidates for surgical treatments should receive full disclosure of the success rates, complications, and late failure rates of each procedure considered.
  5. Since outcome data are not generally available, and not all facilities are accredited by the AASM, it is especially important that patients consult with their personal physician to identify the sleep disorders facility appropriate for their needs.

Background

Purpose

This assessment outlines diagnostic and treatment options for obstructive sleep apnea (OSA), the most common type of sleep-disordered breathing. Information provided in this assessment is limited to OSA in adults and should not be applied to a pediatric population. The goals of this assessment are to summarize findings in the medical literature regarding the clinical effectiveness of surgical treatments compared with behavioral treatments and nasal continuous positive airway pressure (nCPAP), and to discuss unresolved issues surrounding patient selection and outcomes measurement in sleep centers and laboratories. This assessment is limited to the technologies and procedures listed above. Pharmacological regimens, oral devices, and bilevel positive airway pressure are also used to treat some patients with OSA; however, they are not addressed in this assessment. Abbreviations and acronyms used in this assessment, along with their definitions, are attached in Appendix I.

Obstructive Sleep Apnea

Sleep disordered breathing is a complex group of conditions related to abnormalities in airway dimensions, tone, and ability of airway components to open. The causes and course of sleep disordered breathing are not fully understood. The upper airway is susceptible to collapse or narrowing during sleep due to increases in the size of soft tissue structures (tonsils, tongue base, soft palate, lateral pharyngeal walls, and parapharyngeal fat) or by craniofacial or nasal abnormalities.1-3

Obstructive sleep apnea is also referred to as OSA syndrome. For the purposes of this assessment, the term obstructive sleep apnea will be used. Apnea is defined as the complete cessation of airflow through the nose and mouth for greater than or equal to 10 seconds. If there is respiratory effort to resume airflow, the apnea is considered to be obstructive. Absence of respiratory effort indicates the brain is not responding to signals from the respiratory tract. This is labeled central sleep apnea. In mixed apnea, both obstructive and central apneas are present.

Individuals with OSA experience repeated apneas and/or hypopneas during sleep. Hypopnea is defined as a >30% decrease in the depth of respiratory movements lasting for >10 seconds and accompanied by some degree of oxyhemoglobin desaturation. The severity of OSA is determined by the numbers of apneic and/or hypopneic episodes that occur per hour of sleep, measured during polysomnography. Severity is defined by one or more of the following:4

  • Respiratory disturbance index (RDI), also called the apnea-hypopnea index (AHI), is the mean number of respiratory disturbances per hour of sleep. The RDI is a calculation of the total number of apneas and hypopneas divided by number of hours of sleep.
  • Apnea index (AI): Mean number of apneic episodes per hour of sleep.
  • Hypopnea index (HI): Mean number of hypopneic episodes per hour of sleep.
  • Lowest oxyhemoglobin saturation (LSAT) is a measure of the lowest level of arterial oxygen in the blood during sleep. Normal oxyhemoglobin saturation is 95% to 98%.

Definitions of mild, moderate, and severe OSA vary throughout the medical literature. An AHI/RDI between 20 and 40 and an LSAT between 65% and 85% are generally found in mild to moderate OSA. As the AHI/RDI rises and/or the LSAT falls, more severe OSA is generally suspected.5-8

Risk Factors and Occurrence of OSA

Data from the Wisconsin Sleep Study are often used to estimate the prevalence of OSA. This study of 602 men and women between the ages of 30 and 60 estimated 2% of middle-aged women and 4% of middle-aged men in the United States have OSA if a respiratory disturbance index of 5 or greater and excessive daytime somnolence (EDS) are used as minimal criteria.9 These figures, as applied to the Minnesota population, indicate that an estimated 40,000 to 80,000 Minnesotans between the ages of 30 and 60 may have OSA. Research indicates OSA is higher among adults age 65 and older. One self-administered survey showed 4% of women and 13% of men age 65 and older had episodes of sleep apnea.10 These figures, as applied to the Minnesota population, indicate that an estimated 31,000 men and 13,600 women age 65 and over may have OSA.

In addition to the healthy elderly and males, incidence of OSA appears to be higher in adults of any age who have coronary artery disease or hypertension. Obesity is a significant risk factor for OSA.9 However, the majority of patients with OSA are not morbidly obese.11 Other risk factors for OSA include hypothyroidism, adenotonsillar hypertrophy, and nasal obstruction.12

Health Effects

Periods of apnea or hypopnea result in frequent arousal during sleep, abnormally negative intrathoracic pressures, disrupted sleep architecture, and loud snoring. These contribute to EDS, which is associated with deficits in neurocognitive and psychosocial functioning, depression, impotence, morning headaches and decreased work productivity.3,13-15 Daytime sleepiness has been associated with an increased risk for fatigue-related accidents, including motor vehicle crashes.16 Population studies have shown strong associations between sleep-disordered breathing, including sleep apnea, and an increase in motor vehicle accidents.17,18 No studies analyzing the morbidity, mortality, and economic implications of these accidents were found in the medical literature.

Although many conditions have been associated with OSA, no causal links between untreated OSA and these conditions have been established. Conditions associated with untreated OSA include systemic and pulmonary hypertension, myocardial infarction, cerebrovascular disease, cardiac arrhythmias, and sudden death. Patients with OSA appear to have diminished long-term survival with a higher likelihood of cardiovascular disease-related morbidity and mortality. Early diagnosis and treatment of OSA may reduce the risk of cardiovascular disease and other morbidities in these patients.1,5,7,14,19-23

The National Heart, Lung, and Blood Institute (NHLBI) of the National Institutes of Health (NIH) has initiated a multicenter cohort study, the National Sleep Heart Health Study, to determine whether cardiovascular disease and other conditions are a consequence of sleep-disordered breathing, including OSA. The study has enrolled approximately 6500 subjects from 6 investigative centers throughout the United States. The University of Minnesota is one of the field centers. Data from the study will assist in determining whether sleep-disordered breathing is directly associated with an increased risk of coronary heart disease events, stroke, increased blood pressure, and all-cause mortality. Follow-up studies on the entire cohort or subsets of the cohort will help to determine whether sleep disordered breathing is associated with a variety of conditions, including recurrent heart disease, stroke, daytime sleepiness, blood pressure, and cardiac arrhythmias. Final results from this study are not expected for several years. Interim findings will be published in the next 2-3 years.24,25

Evaluation of the Evidence

Methodology and Quality of Evidence

The evidence evaluated was obtained from searches of the MEDLINE, EMBASE, and Current Contents databases spanning the years 1990 to December 1998. The searches were limited to adult subjects, randomized controlled trials, clinical trials, review articles, and clinical practice guidelines. A full description of the methodology is attached in Appendix II.

Analyses of clinical studies on OSA therapy are severely limited by their methodological deficiencies and problems in study design, which create difficulties in interpreting the data and arriving at valid conclusions. The vast majority of studies identified in searches of the peer-reviewed medical literature were either nonrandomized controlled studies or prospective or retrospective case series without controls. Many of the studies had small sample sizes and low statistical power, a problem further compounded by high numbers of dropouts and losses to follow-up. Follow-up data were commonly missing for a number of patients. Most of the studies were also limited by relatively short follow-up times.

Although the majority of studies presented P values, which provide some information about the statistical significance of the association, very few provided confidence intervals, which would allow for a better determination of clinical significance.

Other problems that hampered the comparability of the data between the reviewed studies were interstudy differences in patient populations with regard to OSA severity, age, body weight, comorbidity, and concomitant or prior treatment, as well as differences in treatment protocols or techniques, criteria for response, methods of diagnosis and monitoring. In addition, there is a paucity of data on patient satisfaction, quality of life, long-term morbidity and mortality rates, and cost-effectiveness for each of the OSA treatments.

Diagnosis and Monitoring of Obstructive Sleep Apnea

This assessment discusses overnight full-channel polysomnography (PSG), the most commonly used method to diagnose sleep apnea. Unresolved issues regarding PSG are the degree to which standards of care and sleep laboratories and center oversight are needed, and the relative safety and effectiveness of in-home PSG and other alternatives as compared with laboratory-based overnight PSG.

Standards of Care

A clinic, hospital, or other facility may establish a sleep disorders program with no review or oversight by a professional group. Thus, determining the quality and standard of care of a particular program is difficult for professionals and nearly impossible for patients. The American Academy of Sleep Medicine (AASM) accredits sleep laboratories and centers.26 The American Board of Sleep Medicine, established in 1991, certifies physicians and PhDs in sleep medicine.27 A sleep disorders laboratory is defined as a facility that "provides diagnostic and treatment limited to sleep-related breathing disorders." The AASM defines a sleep disorders center as "a medical facility providing the services of a laboratory plus ancillary services available to diagnose and treat people who show symptoms of sleep disorder, but may or may not have been identified as having a sleep disorder." Approximately 310 sleep disorder centers and 35 laboratories in the United States are accredited by AASM. Seven sleep disorders centers are accredited in Minnesota: one in Duluth, one in Rochester, and five in the Twin Cities metropolitan area. In some states, accreditation is tied to reimbursement of services. This is not the case in Minnesota. No data was found for this assessment on the number of unaccredited facilities in Minnesota or number of procedures performed.

The AASM, American Thoracic Society (ATS), and the NIH have issued clinical practice guidelines concerning several technologies associated with diagnosing and treating OSA. Summaries of the guidelines are attached in Appendix III.

Measures of Excessive Sleepiness

In the literature reviewed, overnight PSG is considered the gold standard of OSA diagnosis and follow-up. PSG provides objective data on the type and severity of sleep-disordered breathing. Candidates for PSG include patients with EDS and those with witnessed apneas; it is not routinely indicated for patients whose only symptom is snoring. Prior to PSG, sleep questionnaires are used to evaluate common symptoms of OSA such as loudness and frequency of snoring. Patients and/or their bed partners are questioned about snoring patterns and intensity, sleep habits, gasping for air at night, limb movements, feelings of fatigue or falling asleep during the day, falling asleep at work or while driving, alcohol, caffeine, and sedative use, sleeping position, shift work, weight gain or loss, morning headaches, nasal congestion or obstruction, and observed sleep apnea.

Somnolence is assessed by subjective scales or surveys including the Epworth Sleepiness Scale (ES) or the Multiple Sleep Latency Test (MSLT). For the ES, a patient rates his or her propensity to fall asleep during eight situations ranging from lying down to rest, to sitting, to conversing. The likelihood of falling asleep is rated on a scale from 0 to 3, with 3 representing the highest likelihood of falling asleep. The total score ranges from 0 to 24, with a score of < 7 considered within normal limits and a score of > 9 suggestive of sleep-disordered breathing.28 The MSLT is an objective test in which a patient is given four or five 20-minute opportunities to fall asleep at set intervals during the day (usually every two hours). The tendency of a patient to fall asleep in a comfortable setting is measured. It is considered a reliable, validated measure of sleepiness, but does not correlate strongly with severity of OSA.3 The MSLT has limitations, for example, it does not control for the mental state of the person tested and assumes the ability to fall asleep is directly associated with sleepiness, which may not always be the case.29

Laboratory-Based Polysolmnography

Presence of OSA is determined through overnight PSG, a laboratory sleep study. The PSG consists of modified electroencephalogram (EEG) to monitor brain activity, bilateral electro-oculogram (EOG) to monitor eye movement, submental and anterior tibialis electromyogram (EMG) to monitor limb activity, oral and nasal thermistors to monitor airflow, chest-wall and abdominal piezoelectric bands and intercostal EMG to monitor respiratory effort, ear or finger pulse oximetry to monitor arterial oxygen saturation (SaO2), and V1 telemetry to monitor cardiac activity. Electrocardiography (ECG) may also be included. Respiratory effort may be monitored by respiratory inductance plethysmography. The PSG provides data on the RDI, AHI, AI, and the LSAT. Continuous esophageal and pharyngeal pressure measurements may be added to indicate respiratory effort and to help determine the site of obstruction.30

Night-to-night variability in PSG findings due to interobserver differences in scoring, variability in sleeping position, alcohol ingestion, or nasal congestion may explain seemingly inconsistent results within individual patients and the lack of correlation between symptomatic improvement and sleep test results.4,7

Alternatives of Laboratory-Based PSG

In a 1998 review of literature, the Agency for Health Care Policy and Research (AHCPR) of the U.S. Public Health Service4 concluded that if the estimated prevalence of OSA in middle-aged adults is correct (2% to 4%), the costs of full-channel PSGs to diagnose the condition would be prohibitive. The report stated that simpler and less expensive diagnostic tests as well as simpler prescreening tests prior to full-channel PSG are needed.4 A summary of the conclusions is attached in Appendix IV.

Portable PSG devices are available for diagnosing sleep apnea outside a sleep laboratory. Home studies have been discussed in the medical literature as having value for those patients with limited access to laboratories due to distance or disability.31 Home-based PSG may provide cost savings in that technician and facility charges are avoided.32,33

Few studies have been completed comparing the accuracy of diagnosis using data from home and full PSG in a sleep laboratory or center. However, data from completed studies indicate the effectiveness of PSG in the home compares favorably with laboratory-based PSG.31,32,34 Concerns regarding the effectiveness and reliability of home PSG data include a lack of standardization in terms of the physiologic parameters measured and the techniques used for recording and interpreting data gathered during the study.4,35,36 For example, one difficulty reported in the literature was loss of data due to improper placement of sensors by patients. A study on patient satisfaction found that a significant percentage of patients preferred full laboratory PSG due to apprehension and uncertainty in administering an at-home test.32

OSA is also diagnosed and monitored by recording the number of O2 desaturations using ear oximetry and recording respiratory and body movements while the patient sleeps in a static-charge-sensitive bed (SCSB). In a SCSB recording, obstructive apneas or hypopneas typically appear as periodic, diamond-shaped respiratory movement patterns accompanied by repeated O2 desaturations.37,38

Additional Diagnostic Techniques

Modified Mueller Maneuver

The Modified Mueller Maneuver (MMM) is used to identify a specific site of pharyngeal obstruction. With the patient sitting or lying in the supine position, the upper and lower pharynx are visualized by a fiberoptic nasopharyngoscope at end expiration. The patient then attempts to inspire while the mouth and nose are occluded. Obstruction or collapse that occurs during negative inspiration, while not a direct correlate for the site of obstruction during sleep, is believed to indicate the most likely site(s) of obstruction during sleep. The degree of collapse is graded separately at the retropalatal area, the lateral pharyngeal walls, and the tongue base as follows: 0 for no collapse; 1+ for a 25% reduction in cross-sectional area; 2+ for a 50% reduction in area; 3+ for a 75% reduction in area; and 4+ for complete obstruction.2,7,15,21,39

Accurate identification of the exact site(s) of airway obstruction in OSA patients is complicated by the fact that obstruction occurs during sleep and is difficult to assess by procedures in which the patient is awake.7 A limitation of the MMM for diagnosis and postoperative assessment of OSA is that it is a subjective procedure during which the observer cannot readily be blinded since the surgical changes would be evident. In addition, only the airway lumen can be observed, not the surrounding soft-tissue structures. The data provided by this procedure has not yet been proven to accurately predict surgical response.2,7,39,40

Radiograph

Cephalometric radiographs are used to screen patients for craniofacial skeletal abnormalities prior to treatment. Treatment efficacy is also assessed by a comparison of pre- and postoperative standard cephalometric radiographs. Outlines of the posterior pharyngeal wall, soft palate, base of the tongue, hard palate, maxillary incisors, mandible, and hyoid are traced, digitized by a scanner, and the images are analyzed using a computer program. Measurements are made of the posterior airway space, minimal posterior airway space, posterior uvula airspace, tip of the incisor-to-tongue base distance, mandibular plane-to-hyoid distance, and cross-sectional area of the third cervical vertebrae. The preoperative values are compared with scaled postoperative measurements.15,39

Treatment of Obstructive Sleep Apnea

Various treatment options for OSA are available depending upon the site(s) of the obstruction or collapse, symptom severity, and extent of clinical complications. Recognized therapies include behavior changes, nasal continuous positive airway pressure (nCPAP),dental or oral appliances, and surgical procedures. This assessment focuses on nCPAP, weight loss, and surgical treatment of OSA. Patient selection and the appropriateness of follow-up sleep studies are unresolved issues surrounding medical and surgical treatments for OSA.

Patient Selection

In its review of diagnosis techniques for OSA, the AHCPR noted that, in view of its high prevalence and potentially serious morbidity, OSA is a major public health problem. The agency stated that there are questions about how and which patients should be tested, and about the implications of test results with respect to the risk of serious clinical complications.4

There is a scarcity of information regarding the extent to which more conservative or behavioral therapies are utilized for patients prior to surgical treatment. As the data discussed below suggest, surgical treatments for OSA have mixed results. Careful selection and determinations of the cause(s) and severity of OSA are necessary to determine if or when surgical treatment is most likely to be effective. Obesity has been associated with severity of OSA and has been identified as a factor in failure of several surgical therapies. However, it is unclear to what extent weight control is actively pursued as a treatment prior to surgical procedures.

Additional prospective, randomized, controlled trials with adequate sample sizes and well-defined inclusion criteria and outcome measures are needed to compare response rates (RDI, AHI, AI, and LSAT), symptomatic improvement, quality of life, patient satisfaction, complication rates, long-term morbidity and mortality rates, and cost-effectiveness between treatment groups. Multi-variate analyses are needed to determine specific variables that contribute to patient outcomes so that patient selection criteria can be refined. The completion of such studies will help to more clearly define the roles of each of the medical and surgical treatments for OSA and, ultimately, to improve treatment efficacy and safety and cost-effectiveness.

Definition of Treatment Effectiveness

The generally accepted definitions of a positive response to OSA treatment include one or more of the following.37,41,1,5,6,15,38

  • Reduction in the AI by >50% from baseline and/or an AI <10; a reduction in the RDI or AHI by >50% from baseline and/or an RDI or AHI < 10 or < 20.
  • Increase in the LSAT by > 50% and improvements in EDS, snoring, sleep architecture, sleep latency, and sleep efficiency.
  • Reduction in the number of O2 desaturations > 4% per hour of sleep (ODI4).

Behavioral and Medical Treatments

Proper body positioning (sleeping on the side and not in the supine position) can lessen severity of OSA in patients whose condition is related to sleeping position. Other behavioral changes that have been shown to lessen the severity of OSA in some patients include avoiding alcohol, sedatives, and tobacco use. Behavioral measures help reduce exacerbations of OSA, but are not curative. Behavioral changes must be maintained to be of benefit; however, many patients are unable to sustain the changes needed for resolution of OSA symptoms.

Medical treatments include nasal decongestants, which may improve nasal obstruction if it exists. Some patients may be candidates for oral appliances, worn at bedtime, that help to maintain an open airway while the patient is sleeping.1,8,13

Weight Control

The role of body weight in development of OSA and the effectiveness of weight loss in improving OSA symptoms is complex and controversial. Obesity is a risk factor for OSA. However, daytime sleepiness with associated decreases in activity and other metabolic factors associated with OSA may promote weight gain.42,43 OSA may progress in patients who demonstrate weight gain. Increased adipose tissue deposits in the lateral pharyngeal fat pads and the increased muscle mass associated with weight gain are believed to cause airway obstruction and OSA. The exact mechanisms whereby weight loss results in improvements in OSA are unknown. Potential mechanisms by which weight loss may improve OSA include changes in upper body structure and decreases in upper airway collapsibility.1,11,44-46

Clinical studies that examined the effects of controlled diet and weight loss on OSA consisted of two prospective, non-randomized controlled trials, two uncontrolled case series, and one retrospective non-randomized controlled trial. Follow-up times ranged from 5 months to 7 years in study populations consisting of 13 to 127 patients with mild-to-moderate or moderate-to-severe OSA. In these studies, AHI/RDI, LSAT, and/or hypertension improved following weight loss, as did sleep architecture, EDS, and the Pcrit (nasal pressure below which the airway occludes). In one study, however, the patients continued using nCPAP, which may have confounded the effects of weight loss on OSA improvement. In one case series, weight loss had no additional effects on improvement in AHI or snoring achieved by nasal spray use and sleeping in the lateral position; however, in patients who lost >3 kg, snoring improved significantly. One long-term retrospective analysis compared the efficacy of tracheostomy and weight loss in patients with moderate-to-severe OSA. Results compared at 7 years showed 18.3% of tracheostomized patients had greater or unchanged EDS. Among weight loss patients, 81.9% had greater or unchanged EDS. Total and vascular disease-related mortality rates were significantly lower among the tracheostomized patients compared with the weight loss patients at the same follow-up (2.8% vs. 17.3%, and 1.4% vs. 11%, respectively).11,19,20,47

In one long-term study on the effects of nCPAP or weight loss on OSA, multivariate analysis showed that a change in BMI was the only variable significantly and independently associated with reduced blood pressure in OSA patients with hypertension.20 Weight levels must be maintained to be beneficial to the patient. Many patients are unable to maintain non-obese weight levels over the long term.48

Nasal Continuous Positive Airway Pressure (nCPAP)

Use of nCPAP while sleeping, is the mainstay of treatment for patients who fail conservative therapies and is highly effective. While sleeping, the patient wears a plastic mask or nasal prongs connected to a positive pressure device with provisions for adjunct therapy with supplemental oxygen or humidification of inspired air. Blowers generate a bias flow to deliver positive pressure. Flow rates ranging from 20 to 60 L/min generate pressures of 2 to 20 cm H2O pressure. With monitoring by PSG, the pressure level is titrated to a level that restores airway patency, improves arterial oxygenation, and ensures uninterrupted sleep. Patients must be followed regularly to assess treatment efficacy and to verify compliance.

The effects of nCPAP are only maintained while the device is being used. A number of patients find nCPAP uncomfortable and restrictive. As a result, long-term compliance is variable.45 Subjective reports suggest that long-term compliance rates range from 50% to 85%, while covert monitoring has revealed compliance rates of less than 50% for all night usage. The most consistent factor associated with improved compliance is improvement in levels of sleepiness, alertness, and other daytime symptoms recognized by patients or their families. 45,49-51

The efficacy of nCPAP was investigated in 3 randomized controlled trials, 2 non-randomized controlled trials, and 1 quality of life case-series analysis reviewed for this assessment. Follow-up times ranged from 3 to 6 months to a mean of 512 days, whith populations comprised of 27 to 126 patients with mild-to-severe OSA. Response rates, defined as improvements in AHI, AI, LSAT, and/or ODI4, ranged from 62% to 100%. EDS, snoring, and sleep architecture were generally improved when nCPAP was used. In one study, AI and hypertension improved in 29% of hypertensive patients with OSA during a follow-up of > 1 year; BMI was the only variable that significantly and independently predicted improvement. In another study comparing survival in nCPAP and UPPP-treated patients, 2.4% of nCPAP patients died compared with 4% of UPPP-treated patients during 6 years of follow-up; however, the probability of 5-year survival was not significantly different between the nCPAP-treated patients (0.95 ± 0.03) and the UPPP patients (0.94 ± 0.02). Survival was not significantly affected by postoperative AI severity or arterial SaO2 levels. In a randomized controlled trial, significantly more nCPAP treated patients had a normal ODI4 at 1 year (100%) compared with conservatively treated patients, i.e., those advised to lose weight (5%). Relapse rates were not evaluated in these studies.8,14,20,38,50 The quality of life case-series analysis found that after 8 weeks of nCPAP therapy in 29 patients with PSG documented sleep apnea, quality of life measures were improved. Based on administration of a standardized pretreatment and post-treatment survey, vitality improved by 75%, social functioning by 90%, and mental health by 96%.52

Complications associated with nCPAP use include: local skin irritation and nasal and throat dryness (50%), nasal congestion or rhinorrhea (25%), and eye irritation (25%). Rare complications include pneumocephalus, bacterial meningitis, conjunctivitis, massive epistaxis, and atrial arrhythmia.49 In the studies reviewed, the following complications were reported: rhinorrhea (54%), dry throat and nose (15%), mask use discontinuation due to discomfort (15%), disturbed by machine noise (7.7%), nasal symptoms (29%), and sense of suffocation (29%).8,38,50

Part-time or inconsistent use of the device does not adequately control OSA. The mask pressure required to suppress apneas and hypopneas and their associated O2 desaturations and arousals varies with body position and sleep stages and does not remain constant throughout the night. Patients who fail or cannot comply with medical treatment may be candidates for surgical treatment. 1,5,8,12-15,38,50

Surgical Treatments

Prior to 1980, the only surgical treatments available for OSA included tonsillectomy, adenoidectomy, nasal surgery, and tracheostomy. This assessment focuses on treatments developed after 1980. These include uvulopalatopharyngoplasty (UPPP), pharyngeal surgeries, and laser-assisted uvulopalatoplasty (LAUP).

Uvulopalatopharyngoplasty (UPPP)

Introduced in 1980, UPPP corrects retropalatal obstruction and increases the size of the oropharyngeal airway. This surgical procedure involves excision of the tonsils, if present; excision of the uvula and posterior portion of the soft palate, and excessive pharyngeal tissue; and the removal and reshaping of the posterior and anterior tonsillar pillars in the lateral pharyngeal walls.1,2,21 UPPP may be combined with other pharyngeal surgeries, or with nasal septoplasty or tonsillectomy if there are multiple sites of obstruction. Other pharyngeal and tongue base reduction surgeries improve patency in other areas of the airway. This and other pharyngeal surgeries are performed under general anesthesia and require hospitalization.

Careful preoperative examination is needed to identify the airway obstruction site(s) and to select the appropriate surgery. Studies of UPPP have been unable to determine reliable preoperative criteria to predict the success of the procedure, and the exact mechanisms for treatment success or failure following UPPP are unknown.53 Studies evaluating the efficacy and safety of UPPP for mild-to-severe OSA consisted of two prospective and one retrospective case series, one nonrandomized controlled trial, and one randomized controlled trial, with follow-up times ranging from 3 months to 8 years and populations of from 10 to 149 patients. The response rates, with respect to improvements in RDI, AHI, AI, and/or LSAT, ranged from 18% to 81.4% and varied according to the criteria for response. Response rates were lower at later follow-ups compared with earlier postoperative follow-ups. In one study, the response rate decreased from 64% at 6 months to 48% at 4 to 8 years.1,5,12,14,19,22,23,37,54

Of note was the significant rate of relapse over time after UPPP. In up to 37% of patients who initially responded, treatment failed at 2 to 8 years after surgery. In the randomized controlled trial, the median ODI4 was abnormal; however, a significantly higher percentage of UPPP-treated patients (39%) had a normal ODI4 compared with conservatively treated patients treated with conservative treatment (7%).38

Data from most, but not all, studies showed significant improvement in EDS, snoring, and sleep architecture. Similarly, in some studies, a lower preoperative BMI and/or lower OSA severity were significantly predictive of a successful outcome whereas, in other studies, these variables had no effect on surgical response. In the non-randomized controlled study that examined long-term survival in UPPP and nCPAP patients, death rates during 6 years of follow-up were higher in UPPP patients who were not followed with PSG, but were not significantly different between UPPP- and nCPAP-treated patients. There were more cardiovascular deaths in the UPPP group, but, due to the small numbers, it was not possible to point to OSA as the cause.5,14,21,23,37,38

The results of UPPP on OSA are variable. Most studies report a response in approximately 50% of patients. In a meta-analysis of 37 published studies, the overall response to UPPP was 40.7% when the criteria for success was defined as > 50% reduction in AI or RDI and a postoperative AI of < 10 or an RDI of < 20. The subjective improvement following UPPP does not always correlate with objective indicators of success determined by PSG, such as a decreased RDI or AI. OSA patients require regular follow-up with objective tests after treatment since silent apneas may persist despite symptomatic improvement. It has been shown that long-term survival after UPPP is poorer in patients who are not followed with PSG compared with those who are monitored. 1,6,7,14,21,23,37,40,41,45,54

UPPP appears to be the most successful in patients with mild OSA with airway obstruction limited to the soft palate rather than the base of the tongue.53 Patients with severe OSA generally respond poorly after single surgical procedures such as UPPP. The high failure rate for the surgery may be attributable to the presence of upper airway obstruction at multiple sites in the pharynx. The failure rate increases when UPPP is performed alone in the presence of retrolingual obstruction. Treatment with UPPP is more likely to fail in patients with severe OSA, retrolingual obstruction, and/or who are obese. UPPP may fail in obese patients due to the compression of the airway by oropharyngeal fat deposits. In non-obese patients, UPPP failures are often related to the presence of obstruction at the level of the hypopharynx or to the existence of a skeletal abnormality that is not corrected by the surgery. 2,21,23,37,38,39,40,41,54

While UPPP may eliminate snoring and other OSA symptoms, the underlying airflow limitations may remain. There has been some concern that, if symptomatic improvement occurs in the absence of a sufficient reduction in objectively measured outcomes such as the RDI, the patient may continue to experience severe apneas that will remain untreated. This could potentially lead to a higher rate of cardiovascular complications.14,38,41,45,55 UPPP can increase the amount of air leaking around the mouth during nCPAP therapy. As a result, success of subsequent nCPAP therapy may be compromised.56

This procedure carries a number of safety concerns. In the studies reviewed for this assessment, 20% of patients undergoing UPPP required postoperative tracheostomy and 40% required reoperation for infection. Other complications included: velopharyngeal insufficiency (7.3% to 15%); myocardial infarction (6%); transient ischemic attack (6%); bleeding (5%); deep vein thrombosis (2.4%); cricopharyngeus spasm (11%); and mouth floor hematoma (11%).5,38

Pharyngeal Surgeries

UPPP alone does not address hypopharyngeal airway obstruction in all instances. When patients have multiple sites of obstruction, collapse of the oropharyngeal and hypopharyngeal airways, or craniofacial skeletal abnormalities, UPPP combined additional pharyngeal surgeries, is more effective for decreasing the RDI, EDS, and snoring. Hypopharyngeal surgery may be used alone for patients whose airway obstruction is limited to the hypopharynx or as a second-line approach in patients who have obstruction of both the oropharyngeal and hyopharyngeal airways and who fail UPPP.7,21,41,54

In a retrospective study that examined the frequency of complications in upper airway surgery which required intensive care monitoring after 125 surgical procedures for OSA, the following complications were reported: airway complications (0.8%), O2 desaturation to < 90%, bleeding (3.2%), severe hypertension (4.8%), mild hypertension (5.6%), wound complications (7.2%), urinary retention (4%), premature ventricular contractions (0.8%), and chest pain (0.8%).57 Surgeries such as inferior sagittal mandibular osteotomy with genioglossus advancement and hyoid myotomy with suspension or advancement (GAHM) and mandibular or maxillary osteotomy and advancement (MMO) are used to correct retrolingual or hypopharyngeal obstruction by moving the base of the tongue forward and increasing the size of the posterior airway space. Midline glossectomy (MLG) removes redundant tissue at the base of the tongue.1,2,15,21,40,41,54

Genioglossus Advancement and Hyoid Myotomy (GAHM)

In GAHM, the genial tubercle, which serves as the anterior attachment of the tongue, and the hyoid bone are advanced following a limited mandibular osteotomy. The hyoid is fixed to the anterior margin of the mandible or, in a more recent modification, fixed to the thyroid cartilage. A partial GAHM consists of the same procedure, but the hyoid is not suspended or advanced. Dental occlusion remains the same after either procedure.

UPPP with GAHM is typically performed in patients with multiple sites of pharyngeal obstruction and who have moderate-to-severe OSA. The studies that evaluated the efficacy and safety of this procedure consisted of two prospective and two retrospective case series, with mean follow-up times ranging from approximately 4 to 9 months, and were comprised of from 9 to 239 patients. Response rates, with respect to improvements in RDI/AHI, AI and/or LSAT, ranged from 57.1% to 100% and varied with the criteria for response. In one study, 11% of patients demonstrated clinical worsening indicated by a fall in SaO2. EDS, sleep architecture, and snoring were generally better after UPPP and GAHM. In one study, the response rate was lower for patients with more severe OSA. In another study, AI and BMI were not significantly related to surgical outcome; however, there was a paucity of data on variables that predicted surgical response. Long-term relapse, response, and survival rates were not investigated in these studies.7,21,39,41

In the studies reviewed, the following complications were reported: bleeding (8.3% to 25%); odynophagia (8.3%); change in taste (8.3%); gingivolabial sulcus incision dehiscences (15.6%); gingivolabial sulcus wound infection (3.2%); transient paresthesia of the mandibular incisors (100%); screw extrusion and mandibular bony fragments (6.3%); and moderate ecchymosis and edema of neck and facial skin (3.2%).40,54

Maxillomandibular Osteotomy and Advancement (MMO)

The mechanism by which MMO improves upper airway diameter is unknown.2 The most common complication in MMO is transient anesthesia of the cheek and chin, which occurred in 100% of patients in one safety study. Eighty-seven percent of these cases were resolved within 6 to 12 months. No postoperative bleeding, infection, skeletal relapse, or relapse of OSA symptoms occurred.21

In MMO, the advancement of the mandible and hyoid bone results in a greater advancement of the pharyngeal muscles and base of the tongue and, thus, greater airway expansion. The maxilla and mandible are advanced simultaneously via Le Fort I maxillary and sagittal-split mandibular osteotomies. MMO is either performed after a failed UPPP or as the sole procedure for OSA patients with mandibular skeletal deformities associated with a narrowed posterior airway space and tongue base obstruction.1,2,7,21,41,54

In one retrospective case series reviewed on MMO (mean follow-up, 9 months) in 91 patients with moderate-to-severe OSA who had failed UPPP and GAHM (n=24), who had MMO for a craniofacial skeletal abnormality (n=7), or who had failed UPPP (n=60), the response rates with respect to improvements in RDI and LSAT were 100%, 100%, and 96.7%, respectively. Sleep architecture was improved; however, EDS, snoring, and possible predictors of response were not evaluated. No long-term response, relapse, or survival rates were presented in either the study on MMO or those on MLG.21,40,54

Midline Glossectomy and Epiglottidectomy (MLG)

MLG with tonsillectomy and epiglottidectomy is used alone or after UPPP failure to reduce the size of the tongue base. With the patient under general anesthesia given through a tracheostomy, laser is used to resect a segment of lingual tonsil and tongue base from approximately 1 cm anterior to the circumvallate papilla, extending posteriorly into the vallecula to the base of the epiglottis. A tissue section measuring 2.5 to 3.5 cm in width and 2 cm in depth is removed. Partial epiglottidectomy removes excess epiglottic tissue. An advantage of this procedure as opposed to GAHM is that it does not require osteotomy, fixation, or immobilization for bone healing. Obstructions of the nasopharynx are corrected by standard nasal septoplasty with inferior nasal turbinate resection.1,7,40,54

MLG following failed UPPP has a low and variable success rate, with response rates ranging from 25% to 41.7% depending on the criteria used. While it appears that non-obese patients have a better outcome after MLG, the reason why remains unclear. Patients who respond may have specific hypopharyngeal anatomic features that are corrected by the procedure. The efficacy of this surgery requires further analysis in prospective studies.40,54

In one prospective and one retrospective case series that examined the efficacy and safety of MLG and epiglottidectomy, each comprised of 12 patients with severe OSA and with follow-up ranging from a mean of 73 days to 15 months, from 25% to 41.7% of patients demonstrated an improved RDI. Sleep architecture improved in one study but was unchanged in the other. Similarly, the response rate was significantly better in less obese patients in one study, while preoperative BMI, RDI, and LSAT had no significant effect on surgical outcome in the other study. No long-term response, relapse, or survival rates were presented in the studies reviewed on MLG.21,40,54

Laser-Assisted Uvulopalatoplasty (LAUP)

LAUP was developed as a treatment for snoring and may be performed in a physician's office under local anesthesia and light sedation. LAUP improves airway patency through removal of part of the uvula and soft palate bilaterally. Since it does not require general anesthesia or hospitalization, LAUP is less costly than UPPP and other pharyngeal surgeries. However, there are no evidence based guidelines which suggest LAUP is effective or safe as a treatment for OSA.

In 1997, the American Medical Association (AMA) published a Diagnostic andTherapeutic Technology Assessment (DATTA) on the efficacy and safety of LAUP for the treatment of simple snoring and OSA. A panel of 61 physicians in otolaryngology and head and neck surgery, neurology, and pulmonary medicine answered a survey regarding the effectiveness and safety of the surgery. Otolaryngologists on the panel rated the safety and effectiveness of LAUP for simple snoring as established. Overall, panel members defined the role of LAUP in OSA as primarily investigational.15

Clinical studies that investigated the efficacy and safety of LAUP consisted of one randomized controlled trial, one prospective case series, and one retrospective case series, with follow-up ranging from 77 days to > 4 months.5-7 The studies included 34 to 56 patients with mild-to-moderate or mild-to-severe OSA. Response rates, which varied widely according to the criteria used, ranged from 33% to 65.8% and were lower for the stricter criteria. In the two studies that evaluated symptoms and sleep patterns, EDS, snoring, and sleep architecture were improved; however, daytime headaches and mental status were unchanged.6,7

There is a paucity of data on specific variables that predict surgical outcome, as well as on the long-term durability of response after surgery. Only one of the studies examined variables that might affect outcome.5 In this study, LAUP responders had significantly lower AI than non-responders, but BMI, RDI, and LSAT were not significant predictors of surgical outcome. Additional long-term, randomized, controlled trials, with direct comparisons to other types of surgery and medical treatments are needed before definitive conclusions regarding the role of LAUP in OSA therapy can be reached.6,7,15

Due to the problem of immediate and long-term postoperative OSA in some patients treated by LAUP, patients who undergo this procedure must be followed with PSG for extended periods of time. There is a need for further investigation of the long-term durability of response and the rate of relapse after this procedure.5-7,58

In the studies reviewed, throat dryness and tightness occurred in all patients immediately following surgery. Bleeding occurred in 1.8% to 5.3% of patients. Other complications included oral candidiasis (5.3%), velopharyngeal insufficiency (2.6%), and vasovagal episode (1.8%).5-7 Patients with marginal airways are at risk for postoperative airway complications that cannot always be predicted before surgery.55

Tracheostomy

In this surgical procedure, a percutaneous opening is created in the trachea distal to the pharynx and larynx, bypassing the area of pharyngeal obstruction. The diameter of the stoma is maintained by stenting and insertion of a rigid or semirigid hollow tube that extends to the surface of the body. At bedtime, the external end of the tube is unplugged to allow breathing to take place through the tube. During wakefulness, the tube is kept plugged. This redirects airflow to the nose, mouth, pharynx, and larynx.1 Tracheostomy is an effective treatment for OSA; however, due to its negative cosmetic effects and associated morbidity, the procedure is generally limited to emergency situations and when other treatment options are unacceptable.

Costs and Cost-Effectiveness

Studies have found that adult patients diagnosed with OSA tend to be high users of health care services in the years prior to diagnosis.59,60 A study of 181 OSA patients found these patients generated an average $3972.00 per patient in the ten years prior to diagnosis compared to $1969.00 per subject in a matched control group. OSA patients spent an average 6.2 nights in the hospital compared to 3.7 nights among the control group during that same period.60

Few analyses on the cost-effectiveness of the medical or surgical treatments for OSA have been published in the medical literature. Information regarding charges associated with diagnostic and treatment modalities for OSA is available.

Polysomnography

In a set of clinical guidelines published in 1997, the AASM stated that there are no available randomized controlled trials and outcome studies that establish the cost-effectiveness of diagnostic and treatment methods for sleep-testing procedures. The cost of recording, scoring, and interpreting PSG results increases with the numbers of physiologic parameters evaluated and the need to have a technologist present throughout the study.30 In Minnesota, the Medicaid program reimburses PSG measuring 1 to 3 parameters at $422.79, and 4 or more parameters at $437.93. Authorization is required for rental or purchase of nCPAP after 2 months of use.61

In Minnesota, PSG is commonly administered in two parts during a single night to reduce personnel and sleep facility costs. During the first half of the night, patients are evaluated for the presence or absence of OSA. The second half is used to calibrate nCPAP.62

Three prospective studies reviewed for this assessment compared the accuracy of full-night and split-night studies. Data indicate that split-night studies provide reliable information on apnea severity and adequately determine effective nCPAP pressure. There were no significant differences detected between positive pressure titration in patients undergoing full-night and half-night studies. For patients in whom the probability of OSA is uncertain, full overnight PSG may be more cost-effective than a cardiorespiratory sleep study due to the problem of false-negative results in patients with mild-to-moderate OSA for the latter test.63-65

A model comparing the costs and utility of laboratory PSG, home studies, and no testing during the 5 years following initial evaluation of OSA, found that when compared to other medical procedures, laboratory PSG provides sufficient benefit per dollar spent. Quality adjusted life years were favorable for laboratory PSG when compared with those of coronary artery bypass, surgery for main left artery occlusion, renal dialysis, and screening asymptomatic patients for carotid stenosis.66 Although the size and parameters on which the model is based limit the generalizability of the results, it does present a framework for analysis and comparison of the benefits and costs of various diagnostic techniques.67

OSA Treatments

The American Thoracic Society has reported that suggested list prices of nCPAP devices range from $1200 to $1272.49 The Medicaid program in Minnesota reimburses CPAP at $1109.52 if purchased or $92.46 per month if rented with an initial set-up fee of $97.80. Uvulectomy is reimbursed at $469.60 and palatopharyngoplasty at $1905.75. Authorization is required for palatopharyngoplasty.61

Findings and Conclusions

Data Quality

  • Little comparative or generalizable patient outcome data on diagnostic and treatment methods for OSA in adults are available.
  • Evidence in the medical literature shows that diagnosis and treatment of OSA in adults vary greatly between facilities. Interpretation of data was limited due to small study size and lack of controls or randomization of many studies.
  • Few cost-effectiveness analyses on any of the diagnostic methods or OSA treatment for were identified in a search of the medical literature.

Diagnosis

  • OSA is a complex condition which may be exacerbated or relieved by a number of physical and physiological factors. As a result, particular attention must be paid to informing patients on what is and is not known about the effectiveness of diagnosis and treatment strategies for OSA.
  • Professional groups recommend that patients with suspected OSA undergo a complete physical and otolaryngologic examination including medical history and determination of body mass index.
  • Overnight PSG is considered the gold standard of sleep apnea diagnosis. There is controversy, however, on whether the costs of overnight PSG provide substantially better diagnostic information compared with alternatives such as in-home sleep studies.

Oversight of Sleep Laboratories

  • Although the AASM accredits sleep laboratories and centers, there is no centralized oversight of sleep facilities. A clinic, hospital, or other facility may establish a sleep disorders program with no review or oversight by a professional group. Thus, determining the quality and standard of care of a particular program is difficult for professionals and even more difficult for patients.

Treatment Selection

  • Guidelines for diagnosis and treatment of OSA in adults have been developed by several professional organizations; however, there is no clear consensus on patient selection criteria for sleep studies and treatment options.
  • Selection of treatment(s) for individual OSA patients should be based upon balanced consideration of disease severity and site(s) of obstruction, subjective symptoms, risks of morbidity and mortality, and patient choice.
  • Treatment effectiveness is variable and dependent on patient needs. It is believed that treatment must be evaluated over time for good patient outcome.

Medical and Behavioral Treatments

  • Several medical and behavioral treatments for OSA in adults are available, including change in sleeping position, drug therapies, and use of dental devices. This assessment focuses on two approaches; weight reduction and nCPAP.
  • Data in the literature indicate that weight loss in obese adults may be associated with improvements in the objective and subjective signs of OSA; however, many patients return to obese body weight over time.
  • For patients who are inappropriate candidates for behavioral treatments, nCPAP is the mainstay of therapy. Compliance rates are variable due to discomfort and side effects of nCPAP. Compliance is highest among patients who experience improvement in levels of sleepiness, alertness, and other daytime symptoms.

Surgical Treatments

  • Surgery may be appropriate for patients who cannot comply with or are not appropriate candidates for conservative therapies or nCPAP alone. The type of surgery performed should be based upon the specific pathophysiology of a patient's condition.
  • Careful and thorough preoperative examination by radiography, imaging, and direct visualization is needed to identify the airway obstruction site(s) and to select the appropriate surgery.
  • UPPP is most efficacious for patients with oropharyngeal obstruction. The failure rate increases when it is performed alone in the presence of retrolingual obstruction. Response rates to UPPP decrease over time.
  • When patients have multiple sites of obstruction or craniofacial skeletal abnormalities, UPPP combined with GAHM or MMO or MMO alone, is more effective than UPPP alone for decreasing the respiratory disturbance index, excessive daytime somnolence, and snoring.
  • The efficacy of midline glossectomy (MLG) following failed UPPP is relatively low and is variably affected by body weight and OSA severity; the long-term outcome after MLG is unknown.
  • While data indicates laser-assisted uvulopalatoplasty (LAUP) can improve snoring and EDS, no evidence based guidelines suggest LAUP is effective or safe as a treatment for OSA.
  • Tracheostomy is an effective treatment for OSA. Use of this procedure is limited to patients for whom other treatment options have failed due to associated morbidity and negative cosmetic effects.

Recommendations

Based upon the conclusions, the Health Technology Advisory Committee recommends:

  1. The presence and extent of OSA in adults must be documented by established methods, including clinical examination and additional diagnostic procedures including PSG, if necessary. Conditions that may exacerbate OSA must be treated.
  2. In uncomplicated, nonemergent cases, first-line treatment options should include conservative measures such as reduction of alcohol or sedative use, sleeping in the lateral position, and weight loss if the patient is overweight.
  3. In clinically significant OSA, nCPAP is the treatment of choice and should be pursued prior to consideration of surgical therapies.
  4. Patients who may be candidates for surgical treatments should receive full disclosure of the success rates, complications, and late failure rates of each procedure considered.
  5. Since outcome data are not generally available, and not all facilities are accredited by the AASM, it is especially important that patients consult with their personal physician to identify the sleep disorder facility appropriate for their needs.

Appendix I: Definitions

TermAcronym or AbbreviationDefinition/Description
Apnea/hypopnea indexAHIAverage number of respiratory disturbances per hour of sleep. AHI is synonymous with respiratory disturbance index (RDI).
Apnea indexAINumber of apneic episodes per hour of sleep.
Arterial oxygen saturationSaO2 Ear or finger pulse oximetry to monitor arterial oxygen saturation during polysomnography.
Body-mass IndexBMICalculated in kg per m2.
Excessive daytime somnolenceEDSMeasured by analog scales or the Epworth Sleepiness Scale (ES) EDS is a measure of a patient's likelihood of falling asleep in daily living situations.
Mandibular osteotomy with genioglossus advancement and hyoid myotomyGAHMA pharyngeal surgery performed alone or in uvulopalatopharyngoplasty (UPPP).
Hypopnea indexHITotal incidences of decrease in depth and rate of respiratory activity
Laser-assisted uvulopalatoplastyLAUPSurgery that can be done on an outpatient basis; developed as a treatment for snoring.
Lowest oxyhemoglobin saturationLSATA measure of the lowest level of arterial oxygen in the blood during sleep. Normal oxygen saturation is 95% to 98%.
Mandibular osteotomy with genioglossus advancement and hyoid myotomyGAHMA pharyngeal surgery performed alone or in uvulopalatopharyngoplasty (UPPP).
Maxillomandibular osteotomy and advancementMMOA pharyngeal surgery performed alone or in addition to uvulopalatopharyngoplasty (UPPP).
Midline glossectomyMLGA pharyngeal surgery performed alone or in addition to uvulopalatopharyngoplasty (UPPP).
Modified Mueller maneuverMMMA diagnostic procedure used to identify a specific site of pharyngeal obstruction.
Maxillomandibular osteotomy and advancementMMOA pharyngeal surgery performed alone or in addition to uvulopalatopharyngoplasty (UPPP).
Multiple sleep latency testMSLTA measure of the period between the time a person lays down to rest and onset of sleep.
Nasal continuous positive airway pressurenCPAPThe mainstay of treatment for patients whose OSA does not respond to conservative therapies. In nCPAP, a positive air pressure device delivers a calibrated level of air to the patient through nasal prongs or a plastic mask.
O2 desaturations of > 4% per hour of sleepODI4 One parameter of PSG, it measures oxygen levels through ear oximetry.
PolysomnographyPSGMultiparameter sleep study to determine the presence of OSA and calibrate CPAP.
Respiratory disturbance indexRDIAlso called the apnea-hypopnea index (AHI), the RDI is a calculation of the total number of apneas and hypopneas reported and divided by number of hours of sleep.
Static-charge-sensitive bedSCSBOSA is also diagnosed and monitored by recording the number of O2 desaturations using ear oximetry and recording respiratory and body movements while the patient sleeps in an SCSB.
UvulopalatopharyngoplastyUPPPA type of surgery for OSA that enlarges the oropharynx.

Appendix II: Methodology

The evidence evaluated for this assessment was obtained from searches of the MEDLINE, EMBASE, and Current Contents databases spanning the years 1990 to December 1998 using the following search terms: obstructive sleep apnea, diagnosis, therapy, and surgery combined with uvulopalatopharyngoplasty, UPPP, laser uvulopalatoplasty, LAUP, pharyngoplasty, lingualplasty, glossectomy, mandibular osteotomy, genioglossus advancement, hyoid myotomy, maxillomandibular osteotomy, tracheotomy, tracheostomy, nasal continuous positive airway pressure, weight loss, and polysomnography. The searches were further limited to adult subjects, randomized controlled trials, clinical trials, review articles, and clinical practice guidelines.

The criteria for inclusion of a clinical trial in this evaluation were: a prospective design, a minimum sample size of 10 adult OSA patients, a minimum follow-up of 3 months, and the presentation of pre- and post-treatment data on symptoms, EDS, RDI, AHI, AI, O2 saturation, and/or LSAT with assessment by PSG, polgraphy and the SCSB, the MMM, oximetry, cephalometric radiographs, and questionnaires detailing sleep patterns, daytime sleepiness, and nocturnal symptoms such as snoring. When the selection criteria could not be fully met, for example, studies with fewer than 10 patients, follow-up of less than 3 months, or retrospective design, the study was evaluated if it met the remaining criteria.

Additional studies were identified by reviewing the citations of selected articles. Information on practice guidelines was obtained from the Agency for Health Care Policy and Research (AHCPR), the American Academy of Sleep Medicine (AASM), the American Thoracic Society, and the National Institutes of Health (NIH).

Appendix III: Guidelines

American Academy of Sleep Medicine (AASM)

The Standards of Practice Committee of the AASM has established practice parameters on the following technologies associated with diagnosing and treating OSA. The year each practice parameter was published follows in parentheses.

  • Indications for polysomnography and related procedures (1997)
  • Treatment of obstructive sleep apnea in adults: efficacy of surgical modifications of the upper airway (1996)
  • Treatment of snoring and obstructive sleep apnea with oral appliances (1995)
  • Use of laser-assisted uvulopalatoplasty (1994)
  • Use of portable recording in the assessment of obstructive sleep apnea (1994)

Indications for Polysomnography and Related Procedures (1997)

The recommendations of the AASM for PSG, referring to full overnight PSG unless otherwise indicated, are briefly summarized as follows:30

  • PSG is routinely indicated for the diagnosis of sleep-related breathing disorders. A cardiorespiratory sleep study may be substituted for patients in a high-pretest-probability group, providing that overnight PSG is performed for patients in this group who test negative by the cardiorespiratory sleep study.
  • Overnight PSG is indicated for nCPAP titration in patients with sleep-related breathing disorders.
  • A preoperative clinical evaluation including PSG or a cardiorespiratory sleep study is routinely indicated to identify the presence of OSA in patients prior to LAUP.
  • Follow-up PSG or a cardiorespiratory sleep study is routinely indicated for the assessment of treatment results following surgery in patients with moderate-to-severe OSA and in those whose symptoms recur after apparently successful surgery.
  • Follow-up PSG is routinely indicated for nCPAP-treated patients who lose or gain substantial amounts of weight, and when the clinical response is insufficient or symptoms recur after an initially positive response.
  • Follow-up PSG or a cardiorespiratory sleep study is not routinely indicated in patients treated with nCPAP with continued symptomatic improvement.
  • A multiple sleep latency test is not routinely indicated for most patients with sleep-related breathing disorders. Subjective assessment of EDS should be obtained routinely.
  • The routine use of unattended cardiorespiratory studies or unattended PSG cannot be supported until such studies have been validated.

Surgery of the Upper Airway (UPPP, GAHM, MLG, and Tracheostomy)

Recommendations made by the association are as follows: the presence and severity of OSA must be determined by the evaluation of clinical symptoms and signs and by PSG before surgery is performed; this process identifies patients at risk for complications due to OSA and provides baseline measurements from which to determine surgical efficacy. The goal of OSA surgery is to alleviate clinical signs and symptoms and to normalize sleep quality, the AHI, and SaO2 levels.12

The recommended therapy for moderate-to-severe OSA is nCPAP; this treatment may also be preferred by patients with mild OSA who are symptomatic. Surgery is indicated in patients whose OSA is related to a specific, surgically correctable anatomical abnormality, and may be indicated for patients who have failed or rejected more conservative treatments, who are medically stable, and who desire the surgery. However, in the absence of the identification of a specific anatomical defect, the optimal way to predict the patient's response to site-specific surgery has not been determined. Any one surgical procedure may not adequately eliminate the clinical signs and symptoms of OSA due to the complexity of upper airway collapse or narrowing during sleep.12

With respect to the individual surgical procedures, these recommendations were made:

  • Tracheostomy is the only surgery that has been demonstrated to be consistently effective as the sole procedure for treating OSA; however, due to the cosmetic effects and morbidity associated with this surgery, it is rarely performed as a treatment for OSA, but is limited to situations in which other treatments are not acceptable, or for medical emergencies.12
  • For all surgeries, the patient must be informed about surgical response rates and possible complications, as well as the availability and efficacy of treatment alternatives such as nCPAP and oral appliances.12
  • UPPP, with or without tonsillectomy, may be appropriate for patients who demonstrate narrowing or collapse in the retropalatal region; however, surgical response rates are not necessarily predicted by a thorough preoperative evaluation, and the response rates are variable. UPPP should only be performed when less invasive treatments, such as nCPAP, have been considered.12
  • With regard to retrolingual surgeries, specifically GAHM, surgical success depends upon the surgeon's skills and few centers have experience with this surgery. While GAHM appears to be the most promising, inadequate data are available on the effectiveness of MLG and lingualplasty.12
  • MMO may successfully treat patients who fail UPPP, nasal surgery, MLG, or GAHM; however, this is generally not considered to be first-line therapy.12
  • When postoperative healing is complete, OSA patients should be followed to assess the presence of residual disease, including an objective measurement of the presence and severity of OSA and of sleep disruptions. It is recommended that follow-up be performed with the patient off of nCPAP. In addition, due to the paucity of data on the durability of response following surgery, patients must be monitored for late relapses which can occur after initially responding to surgery.12

Laser-Assisted Uvulopalatoplasty (LAUP)

In a position paper developed by the AASM's Standards of Practice Committee and published in 1994, the AASM stated that the use of LAUP to treat OSA or snoring could not be condoned since there were was a paucity of controlled trials on the procedure in the peer-reviewed medical literature. The committee concluded that, although LAUP may have some efficacy for OSA, its role had not been defined. In fact, it was stated that the elimination of snoring by LAUP could mask the underlying presence of or delay the diagnosis of OSA. Thus, all patients who are being considered for LAUP must undergo a thorough preoperative clinical examination, including PSG, and be followed with PSG until disease remission is confirmed. The perioperative use of narcotics poses risks of airway complications for patients who have had LAUP.55

American Thoracic Society (ATS)

Nasal Continuous Positive Airway Pressure (nCPAP)

The ATS published a statement in 1994 that delineated the indications and standards for use of nCPAP in OSA.49 The major points of this statement are summarized as follows. nCPAP is effective for the treatment of adult patients with clinically important OSA. Treatment with nCPAP is indicated when there is documented evidence of OSA by PSG and clinical impairment. It is not routinely indicated for the treatment of simple snoring without the presence of OSA. The procedure is a safe and effective form of therapy for which complications are rare, and it effectively eliminates OSA, oxyhemoglobin desaturation, and respiratory event-related arousals from sleep. It is associated with reductions in EDS and improved cardiopulmonary function with possible, but unconfirmed, reductions in mortality. Relative contraindications to nCPAP use include bullous lung disease and recurrent sinus or ear infections; however, there are no absolute contraindications. While patients generally report that they are compliant with nCPAP, actual use of the device varies. Higher levels of patient compliance are associated with resolution of EDS, fatigue, and the restoration of mental alertness. The level of nasal airway pressure requires titration to a level that restores adequate ventilation, arterial oxygenation, and maintenance of sleep. Routine outpatient monitoring is recommended to ensure patient compliance, and to assess treatment efficacy. An initial follow-up at 1 month is recommended with additional follow-up at 3 to 6 month intervals. Due to the limitations of subjective reports of compliance, objective assessment is recommended. Nasal CPAP is not curative, and when it is not used, airway obstruction recurs.49

National Institutes of Health (NIH)

In a consensus statement published in 1990 on the treatment of sleep disorders in older people,13 the NIH consensus committee reached several conclusions on the diagnosis and treatment of sleep disorders, including OSA. The findings of this committee are summarized as follows:

  • There is little agreement among researchers as to what is clinically normal and abnormal except in extreme cases (e.g., high indices of sleep-disordered breathing).
  • There is a lack of standardization in measurements and data collection.
  • The natural histories of sleep disorders have not been well-delineated, and there is a need for additional epidemiological studies.
  • There is some disagreement about what constitutes mild and moderate types of OSA; although the criteria for more severe forms is generally agreed upon.
  • Diagnostic evaluation is needed for patients presenting with reported sleeping problems, including EDS.
  • PSG is indicated when a sleep-related breathing disorder is suspected. PSG followed by a multiple sleep latency test may help to quantitate daytime sleepiness.
  • While ambulatory monitoring may be useful to assess the efficacy of OSA therapy, several issues, including technologic advances, standardization of variables, and cost-effectiveness need to be addressed before such monitoring is incorporated into epidemiologic studies or clinical practice.
  • The indications for treatment of OSA include: a high RDI on PSG, repetitive episodes of hypoxemia, and abnormally shortened sleep latency.
  • The decision to treat is largely based upon clinical judgement since no strict thresholds dictating treatment necessity according to disease severity have been developed.
  • Certain general measures, such as weight loss, avoidance of alcohol and sedatives, avoidance of sleeping in the supine position, and management of nasal and nasopharyngeal disease, may suffice as the treatment for OSA.
  • The mainstay of treatment is nCPAP; other treatments such as orthodontic devices require further study.
  • If conservative measures and nCPAP fail or are not tolerated, surgery, such as UPPP, may be an appropriate alternative treatment, particularly when the airway obstruction site is identified. Tracheostomy may be required if other procedures fail or are unacceptable.
  • Regardless of the therapy that is selected, long-term follow-up is required.

Appendix IV: Summary of Concusions by the Agency for Health Care Policy and Research (AHCPR)

Diagnosis of OSA: A Systematic Review of the Literature

The AHCPR completed a systematic review of the medical literature in an effort to identify the strengths and weaknesses of existing methods used to diagnose OSA in adult patients.4 The agency noted that, in view of its high prevalence and potentially serious morbidity, OSA is a major public health problem. There are questions about how and which patients should be tested, and about the implications of test results with respect to the risk of serious clinical complications. The major conclusions of the AHCPR's review are summarized as follows:4

The gold standard method of diagnosis for OSA is overnight, full-channel PSG in a sleep laboratory. This method is intrusive and costly, and interpretation of the results can be difficult.

A standard PSG consists of an EEG, submental (± tibialis) EMG, EOG, respiratory airflow (by oronasal flow monitors), respiratory effort by plethysmography, and O2 saturation by oximetry. ECG and body position are monitored in formal sleep studies and are considered a standard requirement by some groups.

If the estimated prevalence of OSA in middle-aged adults is correct (2% to 4%), the costs of full-channel PSGs to diagnose the condition would be prohibitive. Simpler and less expensive diagnostic tests as well as simpler prescreening tests prior to full-channel PSG are needed.

Possible alternatives to full-channel PSGs or to prescreen patients for PSG include: partial channel PSGs; partial night or daytime PSGs; portable sleep monitoring at home; cephalometric and other radiographs to assess head and neck abnormalities predictive of OSA; MRI and CT; anthropomorphic measurements, e.g., neck circumference; nasopharyngeal and laryngeal endoscopic measurements of structure and function; and focused questionnaires.

In an analysis of 71 studies of 7572 patients that employed full-channel PSGs to diagnose OSA, variability in PSG definitions of apnea and hypopnea, and in AI and AHI thresholds for diagnosis, with or without the presence of clinical signs and symptoms, were found. Other observations included variability in the components of standard PSGs, a lack of established standards for PSG channels in OSA diagnosis, and poorly documented night-to-night reproducibility for PSGs.4

Appendix V: Public Comment

Comments received during the public comment period are available by contacting HTAC staff.

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