AUTHOR AND EDITOR INFORMATION

Section 1 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Acknowledgments
• References

INTRODUCTION

Section 2 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Acknowledgments
• References

Background

Upper airway obstruction occurring during sleep (ie, sleep-disordered breathing [SDB]) was first demonstrated in the 1960s. SDB represents a group of physiopathologic conditions that are characterized by an abnormal respiratory pattern during sleep that can be isolated or can coexist with other respiratory, nervous, cardiovascular, or endocrine diseases. Sleep-disordered breathing (SDB) is now known to be widely prevalent in the general population, and it is responsible for or contributes to numerous problems, ranging from fragmented sleep patterns to hypertension to traffic accidents.

Sleep-disordered breathing (SDB) includes obstructive sleep apnea (OSA), which consists of breathing cessations of at least 10 seconds occurring in the presence of inspiratory efforts during sleep. Central sleep apnea consists of similar apneas, but these instead take place in the absence of inspiratory efforts. 

The obstructive sleep apnea syndrome (OSAS) is defined by an apnea-hypopnea index (the total number of episodes of apnea and hypopnea per hour of sleep) of 5 or higher in association with excessive daytime somnolence.

Obstructive sleep apnea syndrome (OSAS) is a potentially disabling condition characterized by excessive daytime sleepiness, disruptive snoring, repeated episodes of upper airway obstruction during sleep, and nocturnal hypoxemia.

Risk factors for sleep apnea include obesity, increased neck circumference, craniofacial abnormalities, hypothyroidism, and acromegaly. Daytime consequences include excessive sleepiness, impaired cognitive performance, and disturbed moods with a reduced quality of life. Excessive daytime sleepiness is reported to be associated with a higher risk of motor vehicle accidents and work place injuries or poor work performance.

If not adequately diagnosed and treated, obstructive sleep apnea syndrome (OSAS) is associated with severe complications such as hypertension, strokes, coronary disease, and neurobehavioral complaints and is probably a predictor of premature death. At least 50% of patients with heart failure have sleep respiratory apneas, and patients with moderate-severe obstructive sleep apnea syndrome (OSAS) have a 3-fold increased risk of developing hypertension.

In general, everyone with sleep-disordered breathing (SDB) snores, but not everyone who snores has sleep-disordered breathing (SDB). Snoring in the absence of sleep-disordered breathing (SDB) is termed primary or simple snoring. However, some evidence indicates that snoring is one end of a clinical continuum with an opposite extreme of severe obstructive sleep apnea. Some health problems may be associated even with primary snoring.

Upper airway resistance syndrome (UARS) is characterized by snoring with increased resistance in the upper airway, resulting in arousals during sleep. This can disturb sleep architecture to the point of causing daytime somnolence. No distinct diagnostic criteria exist for this entity. Patients with upper airway resistance syndrome (UARS) can be treated with nasal continuous positive airway pressure (n-CPAP).

Laryngopharyngeal reflux can cause a patient to suddenly awaken from sleep, gasping for breath. A feeling of terror is often present.

Inadequate sleep time can cause excessive daytime sleepiness. This may be involuntary, as in insomnia, or voluntary. Insomnia is characterized by the inability to fall asleep or awakening during the night and being unable to fall back to sleep. Inadequate sleep time occurs for other voluntary reasons (eg, working more than one job, family responsibilities).

Patients with hypothyroidism can also present with fatigue, daytime somnolence, and obesity. Sleep-disordered breathing (SDB) and hypothyroidism can coexist.

Narcolepsy can also cause excessive daytime sleepiness.

Pathophysiology

Any factors that decrease upper airway size or patency during sleep can lead to intermittent obstruction during inspiration, despite inspiratory effort. If the obstruction is sufficiently prolonged, blood-oxygen levels drop. Then, the patient arouses or awakens. The arousals disrupt normal sleep architecture. These, together with the oxygenation drops, are responsible for the more severe accompaniments of sleep-disordered breathing (SDB), including hypertension, arrhythmias, and death.

Factors affecting upper airway size or patency include numerous anatomic variants and abnormalities (eg, nasal obstruction, retrognathia, macroglossia), obesity, alcohol or sedative intake, and body position during sleep.

Obesity contributes to sleep-disordered breathing (SDB) by changing pharyngeal size and shape. Fat storage in the neck may be particularly associated with risk for sleep-disordered breathing (SDB), although a subset of patients with sleep-disordered breathing (SDB) are of normal body weight. Many of these patients have a family history of snoring or sleep-disordered breathing (SDB).

Alcohol intake near bedtime can cause or worsen sleep-disordered breathing (SDB) by reducing the activity of the upper airway dilating muscles. Alcohol increases both the number and duration of apneic or hypopneic events.

Frequency

United States

Sleep apnea occurs in 4% of men and 2% of women aged 30-60 years. Hypersomnolence is reported with a percentage of 16% in men and 22% in women, while 24% of men and 9% of women have an apnea-hypopnea index of at least 5.

International

Some researchers have noticed an increased incidence of OSA in persons of Asian origin.

Mortality/Morbidity

Excessive daytime sleepiness resulting from sleep-disordered breathing (SDB) can impact focus and concentration, causing decreased work effectiveness. Even mild-to-moderate sleep-disordered breathing (SDB) increases reaction time, causing performance decreases similar to alcohol intoxication. This can lead to motor vehicle accidents and other serious accidents in situations where alertness is required for safety (eg, heavy machinery operators).

Moderate-to-severe obstructive sleep apnea (OSA) is associated with earlier death. The cardiovascular sequelae of untreated obstructive sleep apnea (OSA) include hypertension, cor pulmonale, arrhythmias, and increased risk of myocardial infarction or stroke.

Race

The prevalence of obstructive sleep apnea syndrome (OSAS) among African-American persons seems to be at least equal to and may exceed that among white persons. The prevalence among men in urban India and men and women in Korea is similar to that observed in Western countries.

Sex

All the epidemiological studies indicate that sleep apnea syndrome is more common in men than in women (the male-to-female ratio is 2-3: 1). Epidemiologic studies have reported that obstructive sleep apnea syndrome (OSAS) is a common disorder affecting about 4% of adult males and 2% of adult females.

A retrospective study on 830 patients with OSAS reports a male-to-female ratio (M:F) that increases with the gravity of the disease: 2.2:1 in mild OSAS and 7.9:1 in severe OSAS.²
 
The discrepancy between the lower prevalence of obstructive sleep apnea (OSA), the greater frequency of obesity, and the smaller airway size in women compared with men suggests that a gender difference underlies this condition.

Men tend to have a larger but more collapsible airway during mandibular movement than women and this, in part, may play a role in the positional dependency and severity of obstructive sleep apnea (OSA) in men.

The gender-related protective effect decreases in females who are postmenopausal and not on hormone replacement therapy.

Another possible reason of the lower prevalence of OSAS may be due to the reluctance of many women to report symptoms, mostly considered inappropriate, like snoring, causing a clinical underestimation of the problem in females.

Age

The association between age and obstructive sleep apnea is complex. Several studies have shown a higher prevalence of obstructive sleep apnea in elderly persons compared with middle-aged persons, although daytime symptoms may be less common with advancing age.

The Sleep Heart Health Study demonstrated that the influence of male sex and body mass index on obstructive sleep apnea tends to wane with age. For unclear reasons, the overall prevalence of obstructive sleep apnea plateaus after 65 years of age.

CLINICAL

Section 3 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Acknowledgments
• References

History

The first clue in the history of patients with sleep-disordered breathing (SDB) is loud snoring. This is accompanied by breathing cessation; gasping, choking, and snorting; frequent arousals from sleep; and respiratory effort with no air. Nocturnal arrhythmias and acute blood pressure increases may occur. Morning headaches that dissipate as the day goes on, excessive daytime sleepiness, and poor concentration affect daytime performance. The disorder has been linked to an increased risk of angina, myocardial ischemia, stroke and motor vehicle crashes.

Older men may report getting up numerous times during the night to urinate and are convinced that they awaken because of the urge to urinate. The truth is often the reverse, that they awaken as a result of sleep-disordered breathing (SDB) and then they notice the urge to urinate. These patients are often surprised at their decreased need for nocturnal urination after successful sleep-disordered breathing (SDB) treatment.

Physical

Most patients with sleep-disordered breathing (SDB) are overweight or obese. A patient with a short, thick neck may be predisposed to sleep-disordered breathing (SDB). Scalloped indentations along the lateral tongue (from teeth) are a marker for relative tongue/mandibular arch size mismatch, which may predispose individuals to sleep-disordered breathing (SDB).

Causes

Important clinical risk factors for sleep-disordered breathing (SDB) are as follows:

• Nasal obstruction
• Craniofacial abnormalities
• Mandibular retrognathia
• Micrognathia
• Narrowed, tapered, and short maxillary arch
• Overbite
• Long soft palate
• Modified Mallampati grade III or IV
• Macroglossia
• Tonsillar hypertrophy
• Neck circumference more than 17 inches for men and more than 16 inches for women
• Obesity

Other problems that can contribute to or exacerbate sleep-disordered breathing (SDB) are sedative or alcohol use and poor sleep hygiene.

A very small percentage of patients with sleep-disordered breathing (SDB) have central rather than obstructive sleep apnea. Central sleep apnea can be caused by various neurologic disorders or can be idiopathic.

DIFFERENTIALS

Section 4 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Acknowledgments
• References

Other Problems to be Considered

The differential diagnosis includes simple snoring, central sleep apnea, and other disorders that cause day-time sleepiness (eg, insufficient sleep, a circadian-rhythm abnormality, narcolepsy, periodic limb movement disorder). 

WORKUP

Section 5 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Acknowledgments
• References

Lab Studies

The relation between snoring, obstructive sleep apnea and hypothyroidism has been confirmed by many authors. Thyroid-stimulating hormone (TSH) levels should be determined in patients who are newly diagnosed with sleep-disordered breathing (SDB) because sleep-disordered breathing (SDB) is relatively common among patients with hypothyroidism.

Imaging Studies

Radiologic and diagnostic studies have been used to identify the obstruction site, direct surgical intervention and predict outcomes of sleep apnea surgery. These studies include lateral cephalometric radiographs, CT, MRI, asleep fluoroscopy, asleep and awake endoscopy with Mueller maneuver, upper airway manometry, and acoustic reflection techniques. Most of those techniques have limitations (dynamic and tridimensional evaluation) in the mechanism of occlusion investigation. Ultrafast MRI provides a reliable and noninvasive method for static and dynamic evaluation of the soft tissue structures surrounding the upper airway during the respiratory cycle in wakefulness and sleep.

Other Tests

• The Epworth Sleepiness Scale (Epworth Sleepiness Scale) is a questionnaire filled out by the patient that estimates the likelihood of falling asleep in different situations. This permits a standardized semiquantitative subjective assessment of daytime sleepiness.
• The polysomnography (PSG) is the criterion standard diagnostic test for obstructive sleep apnea syndrome (OSAS).
• • A respiratory event suggestive of obstructive sleep apnea syndrome (OSAS) is defined as a decrease in nasal and oral airflow, alone or with thoraco-abdominal movements, more than 90% (apnea) or more than 50% and less than 90% (hypopnea) that lasted for at least 10 seconds. A decrease in SaO₂ of 4% or more is considered significant oxygen desaturation.
  • Information from the PSG is reported as the Respiratory Disturbance Index (RDI). The RDI is the number of apneas or hypopneas 10 seconds or longer occurring per hour of sleep. A normal RDI is less than 5. A RDI less than or equal to 5 is considered suggestive of simple snoring with no OSAS. Greater than 5 and less than or equal to 15 is suggestive of mild OSAS. More than 15 and less than or equal to 30 is suggestive of moderate OSAS. Finally, more than 30 is suggestive of severe OSAS. The loudness and persistence of snoring (constant versus intermittent) are usually reported. Body position is also recorded so one can determine what position (usually supine) and in what sleep phase (usually rapid eye movement [REM] sleep, when muscle tone is most relaxed) the patient is in when respiratory events occur.
• The PSG has several limits including the necessity to perform the test in a sleep laboratory, high costs, considerable technical expertise, and long analyzing time by the operator. In addition, the examination often needs to be repeated because of the interference of monitoring electrodes with the physiological sleep of the patient (“first night effect”). Therefore, timely access to PSG is often a problem.
• An extensive interest in alternative diagnostic approaches, such as clinical prediction rules and portable monitors, has been expressed. A limited number of questionnaires are available to detect some sleep disorders, but those instruments do not achieve the reliability of PSG, which remains the recommended method of assessing patients with suspected sleep disorders. The role of those questionnaires is mainly of a screening tool for identifying patients at risk for obstructive sleep apnea syndrome (OSAS).
• Various types of ambulatory (to be used at home) monitors can measure parameters such as airflow, chest, and abdomen movements (as indicators of respiratory effort); oxygen desaturations; snoring; pulse; and body position. Although the data from such studies are not as detailed or accurate as an overnight PSG, these studies can often be used to differentiate primary snoring from snoring with apneas and can usually provide an indication of the frequency with which apneas are occurring. In contrast, techniques that measure only one parameter (eg, home oximetry alone) seem to be less accurate than those that track several measurements.
• Acoustic analysis of snoring sounds may help differentiate between primary snoring and obstructive sleep apnea (OSA). Other researchers have investigated the combination of clinical variables such as neck and chest circumference, body mass index, and resting room air oxygen saturation; however, none of these have been shown to differentiate consistently between primary snorers and patients with significant apneas and desaturations during sleep.
• Home sleep testing pursues the goal of simplify the diagnosis of sleep apnea while retaining the essential recording features of PSG.
• • Recent studies suggested that home sleep studies have benefits in terms of time and cost, but for diagnostic reliability, an in-laboratory sleep study may be required in more than half of the cases.
• • EdenTrace portable monitor measures nasal and oral air flow using thermistors, chest wall impedance, oxygen saturation with finger pulse oximetry, heart rate, and movement detected by electrical comparison of the signals from the ECG and the pulse oximetry.
  • The MESAM IV system evaluates sleep-disordered breathing based on an analysis of snoring, heart rate, and saturation change. Even if in many studies there is a good agreement between the AHI measured in the laboratory and with the home sleep testing, there is a risk that ambulatory diagnostic procedures may alter the relationship of patients to their disease and/or the medical staff so that subsequent compliance with treatment may be decreased.
  • The Nightwatch system has the ability to calculate the AHI. It records eye movement (1 channel, piezo electrode), leg movement (1 channel, piezo electrode), arterial oxygen saturation (finger pulse oximeter), nasal oral air flow (thermistor), chest and abdominal movements (piezo electrodes), body position and movement (mercury gauge placed on the chest), and heart rate. The Nightwatch system has also got the ability to send to the laboratory data for analysis by modem 2-minute portions of the complete recording so that signal quality can be assessed and transducer function corrected if needed. However, further studies are necessary before this technology can be put into widespread use.

Histologic Findings

Histology of the soft palate and uvula in snorers and patients with obstructive sleep apnea (OSA) syndrome has been a subject of investigation of many authors. Some authors observed muscular atrophy, dilatation and congestion of the blood vessels, lymphocytic infiltrations, and hypertrophy of superficial salivary glands localized between the muscle bundles and epithelium. Those histopathologic changes were related to the influence of the vibration on the soft palate and uvula and were considered responsible for the excessive flaccidity of these structures. Other authors observed similar contents of glands, muscle, fat, blood vessels, and the epithelium in the uvula and the soft palate of either OSAS and control subjects.

TREATMENT

Section 6 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Acknowledgments
• References

Medical Care

The first task in treating patients with sleep disordered breathing (SDB) is to eliminate all possible contributing factors. This includes weight loss for patients who are obese (see Diet) and elimination of alcohol or sedative use, especially near bedtime. Benzodiazepines, narcotics, and barbiturates can worsen sleep-disordered breathing (SDB), or sometimes they initiate it where it had not previously been present.

A 10% weight loss was associated with a 26% decrease in the apnea-hypopnea index in a population-based study. Weight loss should be recommended for all obese patients with sleep apnea; however, weight loss takes time, and only a minority of patients successfully maintains it.

Body positioning during sleep can improve sleep-disordered (SDB) in some patients. Because lying supine can allow gravity to assist in pulling lax tongue muscles back toward the posterior pharyngeal wall, patients should sleep on their sides, on their stomachs, or propped up 60°. These positions can improve sleep-disordered breathing (SDB) in patients whose symptoms occur primarily while supine.

Avoidance of supine sleeping can easily be accomplished with a sock, tennis ball, and safety pins. The tennis ball in a sock is pinned to the back of the pajamas, positioning the tennis ball between the scapulae. When the patient rolls into the supine position during sleep, this lump is uncomfortable enough that the position is immediately shifted, usually without the patient awakening.

In patients with hypothyroidism and sleep-disordered breathing (SDB), thyroid hormone replacement therapy is usually accompanied by an improvement in the sleep-disordered breathing (SDB).

In some individuals, a mouthpiece may improve the anatomy of the airway to the point that snoring or mild obstructive sleep apnea (OSA) can be corrected. Many types of oral appliances have been designed for the treatment of sleep apnea. Most are custom fit to the teeth of both dental arches to reposition the mandible and to enlarge the retropalatal and retrolingual airway space. However, consistent patient tolerance for this treatment is relatively low and it's less effective than continuous positive airway pressure in reducing the frequency of apnea and hypopnea.

n-CPAP is used as follows:

• When none of the above therapies are appropriate or helpful, n-CPAP is the most effective method to manage OSAS. Patients who are unlikely to benefit from n-CPAP include those with such severe nasal obstruction that n-CPAP cannot be used, patients with such extreme claustrophobia that they cannot tolerate a nasal mask, and patients in whom n-CPAP does not reliably eliminate apneas, hypopneas, and snoring.
• n-CPAP provides a pneumatic stent for the upper airway, eliminating the airway collapse during inspiration. It is administered by a soft mask that covers the nose only. Sufficient pressure is introduced to eliminate apneas, hypopneas, and snoring.
• The criterion standard for determining the amount of pressure required to restore upper-airway patency is traditionally determined during polysomnography by trained technicians. In some centers, this is performed as a split-night study, with data from the first half of the night used for diagnosis of sleep-disordered breathing (SDB). Once this diagnosis is made, if the RDI is sufficient to suggest benefit from initiation of n-CPAP (usually an RDI of 20 or more), the second half of the night's study is used to determine the optimal amount of pressure. The disadvantage of the split-night approach is that the second half of a full night study often reveals more severe sleep apnea, so a diagnostic study limited to the first half of the night can underestimate disease severity.
• The amount of pressure delivered is reported as cm H₂O. An average starting point for CPAP would be 8-10 cm H₂O. Patients report that pressures at these levels feel odd but are tolerable even when beginning treatment and become more tolerable as the patients become accustomed to treatment. Higher levels (>15 cm H₂O) are often not well tolerated.
• When a second overnight study is logistically difficult, some clinicians empirically start a patient on n-CPAP with a pressure of 8-10 cm H₂O. A new generation of n-CPAP machines, on the basis of the patterns of inspiratory airflow, can sense the amount of pressure needed to overcome upper airway resistance. Patients are sometimes started using these machines without a prior titration study. Alternatively, an autotitrating machine can be used for several nights, the record of amount of pressure required to suppress apneas and hypopneas can be downloaded and studied, and a suitable nightly pressure can be determined in this fashion. Also, the amount of pressure required to suppress snoring can be used as an audible guide to appropriate pressures.
• A patient who routinely takes sedatives or ingests alcohol during the evening and does not intend to change this should probably be tested after continuing their usual nightly routine. n-CPAP titration without sedatives or alcohol is likely to lead to undertreatment of the SDB at home, when such patterns are resumed.
• Most patients feel better during the daytime on the first day after beginning n-CPAP. During the first week of treatment, most experience rebound sleep with prolonged episodes of REM sleep. Sleep patterns become more normal after the first week. For these reasons, several weeks of n-CPAP use may be helpful for normalization of sleep patterns in patients with severe sleep apnea who plan to undergo surgery. Sleep patterns should be normalized prior to the planned surgery.
• Regular use of n-CPAP improves both the patients' and their bed partners' quality of life. The treatment lessens depressive symptoms, and improves daytime functioning, blood pressure and insulin sensitivity. In patients with obstructive sleep apnea (OSA) who receive antihypertensive treatment, long-term CPAP was found to be responsible for a significantly reduction of diastolic blood pressure. Asthmatic OSA patients have fewer nighttime symptoms. Other effects of using CPAP include increased vagal tone, increased cardiac output, increased stroke volume, decreased systemic vascular resistance, and reduced risk of cardiovascular mortality.
• Most physicians agree that patients with a respiratory disturbance index (RDI) greater than 20 require treatment. n-CPAP can also be useful for patients with a lower RDI, especially if they experience daytime sleepiness or other symptoms. If the severity of the daytime symptoms and the Epworth Sleepiness Scale score are much greater than would be expected with a particular RDI, a trial of n-CPAP can help determine whether elimination of the sleep-disordered breathing (SDB) leads to improvement of the daytime symptoms, or if other factors contribute to the daytime symptoms.
• Overall compliance rates can be low (46% in one study defining use as at least 4 h/d, 5 d/wk). Noncompliance has been categorized by Zoula et al as tolerance problems, psychological problems and lack of instruction, support, or follow-up. Tolerance problems may be due to side effects (ie, dry mouth, conjunctivitis, rhinorrhea, skin irritation, pressure sores, nasal congestion, epistaxis), mask leaks, difficulty exhaling, aerophagia, chest discomfort, and bed-partner intolerance. Psychological problems include lack of motivation, claustrophobia and anxiety. The points below may assist the physician in improving treatment compliance. Main referred problems include the following:
• • Claustrophobia: Many patients report claustrophobia. They find that the sensation of covering the nose with a mask makes them so uncomfortable that they cannot tolerate wearing the n-CPAP. Sometimes this can be helped with a smaller or more transparent mask design. Use of nasal pillows (inserted into the nostrils) instead of a formal nasal mask may allow such patients to tolerate the n-CPAP.
  • Trouble tolerating initial pressure: Especially when higher pressures (>12-13 cm H₂O) are required for elimination of apneas and hypopneas, patients may find this level of pressure uncomfortable. Many n-CPAP machines have a built-in ramp or gradual increase in pressure. Using this feature, the mask can be placed and pressure begun at a very low and easily tolerated level. Over 30 minutes, the pressure gradually builds to the full amount necessary. Often, the patient can fall asleep during this ramp-up time. The full pressure is not used until the patient is actually asleep.
  • Nasal obstruction
  • • Evaluation by an otolaryngologist reveals whether this is predominantly a fixed skeletal obstruction or a soft tissue obstruction potentially modifiable without surgery. Marked septal deviation or turbinate hypertrophy usually requires surgery for resolution. Alar collapse may be adequately treated by internal or external dilators (eg, Breathe Right strip, Nozovent). Surgery is sometimes required for repair of marked alar collapse.
    • Mucosal edema may be due to allergic rhinosinusitis or to vasomotor or irritative rhinitis. Allergy testing and treatment and pharmacotherapy trials (eg, topical steroids or antihistamines, oral antihistamines, or decongestants) may be beneficial.
    • One way to determine whether sufficient potentially reversible mucosal edema exists to pursue that avenue of treatment is the topical decongestant test. The patient uses a nasal topical decongestant (eg, oxymetazoline) at bedtime for several days, with the patient and bed partner observing for any improvements in snoring or apneas. A marked improvement suggests potentially reversible mucosal edema as a main contributor to the nasal obstruction. Failure to improve suggests a fixed skeletal obstruction that requires surgical correction.
    • Sometimes the dryness of the air or its temperature may be irritating to the patient. Use of in-line humidification and warming of the inspired air may alleviate patient discomfort.
  • Facial or nasal pain: Sometimes this pain can be related to a poorly fitting mask. With the many different types of masks available now, different styles and sizes can be tried to select the optimal fit for each individual anatomy. Because the mask is pulled tight against the face, an edentulous anterior maxilla may not provide the resistance necessary for a good fit. Leaving dentures in at night can help with this. If the facial or nasal pain persists despite mask refitting, evaluation for nasal obstruction or chronic sinusitis may be helpful. The CPAP Pro delivery method anchors the tubing to a platform based on an upper retainer, obviating the need for a forehead strap.
  • Dry eye or other eye discomfort: If the mask does not seal well, egress of pressurized air from the upper end of the mask toward the eye may occur, causing dry eye or even exposure keratitis. Mask refitting usually eliminates this problem.
  • Mouth falling open, awakening with dry mouth: Sometimes a chin strap is required to prevent the mouth from opening at night. A commercially available disposable adhesive bandage may used to pull the chin up toward the lower cheeks.
  • Epistaxis: Epistaxis may be related to the high-flow dry air and may be helped by humidification and warming of the inspired air.
  • Nasal drying: Forced dry air can be irritating to the nose, encouraging mucosal inflammation and crusting. Use of humidified air for nCPAP usually eliminates this problem.
  • Other: Pneumopericardium has been reported with n-CPAP. Pneumocephalus has occurred when n-CPAP was used in a patient with cerebrospinal fluid rhinorrhea. Eustachian tube dysfunction, serous otitis media, bulging of the eardrums, and eardrum perforation have also been reported.
• Although n-CPAP provides good improvement in symptoms and physiologic parameters, compliance with treatment is not good, with regular use sometimes estimated as low as 30%. Rigorous patient education and early reinforcing follow-up may improve long-term use.

Variations of air pressure delivery can sometimes make n-CPAP use more comfortable for patients. Autotitrating positive airway pressure (APAP) continually adjusts the pressure to barely overcome the collapsing forces. Bilevel positive airway pressure (BiPAP) provides higher pressure during inspiration (when the pneumatic splint is needed to prevent obstructive airway collapse) and lower pressure during expiration. C-Flex is another autoadjusting delivery method that increases pressure toward the end of expirations, as collapse would usually begin, and decreases pressure during early expiration. Patients who require higher pressures to overcome obstructive apneas may tolerate these devices better than the one-level n-CPAP, which delivers the higher pressure throughout the entire respiratory cycle.

Following treatment with continuous positive airway pressure (CPAP), some patients with obstructive sleep apnea remain sleepy despite effective CPAP, and attention should be paid to other diagnoses that can be associated to sleepiness. The so called "post-CPAP sleepiness," as a specific disorder, may not exist.

Surgical Care

Surgical care of sleep-disordered breathing (SDB) is discussed in the eMedicine article Snoring/Obstructive Sleep Apnea, Surgery. n-CPAP is often used in the perioperative period to assure good ventilation even in the presence of postsurgical edema. Because of the use of analgesics and swelling of the soft tissues, the pressure needed to maintain a patent airway postoperatively may be greater than the patient had been using prior to surgery.

Consultations

Multidisciplinary sleep teams, including pulmonologists, otolaryngologists, neurologists, and oral-maxillofacial surgeons, may offer the most convenient and comprehensive treatment for these patients.

Diet

Weight reduction in the patient with obesity can dramatically improve sleep-disordered breathing (SDB). Even a modest weight loss can have quite a beneficial effect on the frequency of apneas and hypopneas. Diet and exercise counseling play a major role in the initial therapy for sleep-disordered breathing (SDB). Bariatric surgery may be needed in some cases.

When rapid weight loss occurs after bariatric surgery or successful dieting, the pressure for overcoming apneas and hypopneas is likely to decrease, so retesting is recommended.

Alcohol significantly worsens sleep-disordered breathing (SDB). Eliminating use of alcohol, especially near bedtime, improves sleep-disordered breathing (SDB).

MEDICATION

Section 7 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Acknowledgments
• References

Protriptyline, a tricyclic antidepressant, is the medication most studied in the treatment of sleep-disordered breathing (SDB) and does improve sleep-disordered breathing (SDB). This effect, however, appears to be mainly due to suppression of REM sleep. Because sleep-disordered breathing (SDB) is often most severe during REM sleep, less REM sleep can mean fewer apneas. Other drugs that have been investigated for treatment of sleep apnea include progestational agents, aminophylline, acetazolamide, L-tryptophan, naloxone, baclofen, bromocriptine, chlorimipramine, and prochlorperazine. None of these have shown a consistently helpful effect on sleep-disordered breathing (SDB).

Because some of the effects of sleep-disordered breathing (SDB) are due to hypoxia during sleep; the administration of oxygen would seem like a reasonable treatment. Although oxygen administration improves the lowest blood-oxygen saturation level during sleep and can improve some of the arrhythmias occurring during desaturation, repeated studies have not demonstrated sustained clinically significant improvement in sleep-disordered breathing (SDB) with oxygen administration. Some prolongation of apneas also occurs, particularly at the beginning of therapy. Oxygen administration may be beneficial in a subset of patients. Some patients with other coexistent pulmonary disorders may also benefit from use of oxygen in conjunction with CPAP.

n-CPAP is effective in improving sleep quality and reducing daytime sleepiness. Long-term treatment with n-CPAP reduces both mortality and the acute blood pressure elevation that occurs with sleep-disordered breathing (SDB). Over time, a trend develops toward baseline blood pressure reduction in hypertensive patients with sleep-disordered breathing (SDB).

Modafinil is a wake-promoting medication used in association with CPAP in obstructive sleep apnea syndrome (OSAS). Modafinil has an action similar to sympathomimetic agents (like amphetamine and methylphenidate), although the pharmacologic profile is not identical to that of sympathomimetic amines. The precise mechanism through which Modafinil promotes wakefulness is unknown. Headache and nervousness are the only adverse events reported. There is no benefit using Modafinil in patients with obstructive sleep apnea (OSA) who are not compliant with CPAP, so it should not be administrated in such cases.

Drug Category: Antidepressants

These agents may suppress REM sleep.

Drug Category: Central Nervous System Stimulant, Nonamphetamine

These agents have wake-promoting effects.

FOLLOW-UP

Section 8 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Acknowledgments
• References

Further Outpatient Care

• The n-CPAP does not cure or alter the underlying obstructive sleep apnea (OSA) but rather provides daily relief from the apneas, snoring, hypoxias, and consequent daytime symptoms. After long-term n-CPAP use, a carry-over effect is often noted; therefore, polysomnography results on the first day or two off n-CPAP look remarkably improved. However, this carry-over is short lived, and usually within a week, the snoring, apneas, hypoxias, and daytime symptoms have returned to their original level.
• n-CPAP is highly successful in treating obstructive sleep apnea (OSA), as long as it is used. Unfortunately, compliance with n-CPAP use is not great, with use for at least 4 hours a night on 5 of 7 nights occurring in only about one half of patients. For this reason, regular follow-up visits are mandatory for ensuring continued successful treatment.
• Some physicians see patients on a 3- to 4-month basis during their first year of n-CPAP use and yearly thereafter. Repeat sleep studies are obtained after major weight loss or gain or after major change in daytime symptoms. Many patients happily and successfully use the n-CPAP for years. Others find sustained use impossible. These are the patients for whom surgery may be helpful.
• Even snorers whose polysomnogram does not show sleep-disordered breathing (SDB) should be monitored periodically because they can progress to sleep-disordered breathing (SDB) with time, even without weight gain.
• The Epworth sleepiness scale is as follows:
• • The patient is instructed to rate the chance of dozing off in each of these situations. They are to choose the most appropriate ranking for each of these situations, working out how they would probably respond if it is something they have not actually done recently. The following is the scoring for this scale:

0 - Would never doze off
1 - Slight chance of dozing off
2 - Moderate chance of dozing off
3 - High chance of dozing off

• Score situation

_____ Sitting and reading

_____ Watching TV

_____ Sitting inactive in a public place (eg, theater, meeting)

_____ As a passenger in a car for an hour without break

_____ Lying down to rest in the afternoon when circumstances permit

_____ Sitting and talking to someone

_____ Sitting quietly after a lunch without alcohol

_____ In a car, while stopped for a few minutes in the traffic

_____ Total

Patient Education

For excellent patient education resources, visit eMedicine's Sleep Disorders Center. Also, see eMedicine's patient education articles Snoring and Narcolepsy.

ACKNOWLEDGMENTS

Section 9 of 10  

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Acknowledgments
• References

Special thanks go to Dr. Stefano Rinaldi and Dr. Maria Virgilia De Merulis.

REFERENCES

Section 10 of 10

• Authors and Editors
• Introduction
• Clinical
• Differentials
• Workup
• Treatment
• Medication
• Follow-up
• Acknowledgments
• References

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Article Last Updated: Oct 6, 2008