Sleep-Disordered Breathing and CPAP Treatment & Management

Updated: Apr 16, 2018
  • Author: Vittorio Rinaldi, MD; Chief Editor: Zab Mosenifar, MD, FACP, FCCP  more...
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Treatment

Initial Treatment

Elimination of contributing factors

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 and elimination of alcohol or sedative use, especially near bedtime. Benzodiazepines, narcotics, and barbiturates can worsen 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 respiratory disturbance index (RDI; also referred to as the apnea-hypopnea index [AHI]) 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 maintain it. [60, 61]

Alteration of body positioning during sleep

Body positioning during sleep can improve 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 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.

Thyroid hormone replacement therapy

In patients with hypothyroidism and SDB, thyroid hormone replacement therapy is usually accompanied by an improvement in the SDB.

Use of oral appliances

In some individuals, a mouthpiece may improve the anatomy of the airway to the point where snoring or mild obstructive sleep apnea (OSA) can be corrected. Oral appliances, or mandibular advancement devices (MADs), can be an effective alternative for mild and medium-to-moderate OSA syndrome (OSAS), but they require strict monitoring because of differences in individual response to this therapy. [62, 63]

Many types of oral appliances have been designed for the treatment of sleep apnea. Most are custom fitted 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 is less effective than continuous positive airway pressure (CPAP) in reducing the frequency of apnea and hypopnea. [64]

Restriction or elimination of alcohol use

Alcohol significantly worsens SDB. Eliminating use of alcohol, especially near bedtime, improves SDB. [65]

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Nasal CPAP

When none of the above therapies are appropriate or helpful, nasal CPAP (n-CPAP) is the most effective method of managing OSAS. [66, 67, 68, 4, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 61, 79]  n-CPAP provides a pneumatic stent for the upper airway, eliminating the airway collapse during inspiration. It is administered via a soft mask that covers the nose only. Sufficient pressure is introduced to eliminate apneas, hypopneas, and snoring. (See the image below.)

CPAP machine. CPAP machine.

Most physicians agree that patients with an RDI higher 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 SDB leads to improvement of the daytime symptoms or if other factors contribute to the daytime symptoms.

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.

Determination of required positive airway pressure

The criterion standard for determining the amount of pressure required to restore upper-airway patency is traditionally determined during polysomnography (PSG) 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 SDB. Once this diagnosis is made, if the RDI is high enough to suggest benefit from initiation of n-CPAP (usually ≥20), 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, and thus a diagnostic study limited to the first half of the night can underestimate disease severity.

The amount of pressure delivered is reported in centimeters of water. 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 at the beginning of 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. Newer n-CPAP machines can sense, on the basis of the patterns of inspiratory airflow, the amount of pressure needed to overcome upper-airway resistance. Patients are sometimes started on these machines without a prior titration study. [80, 81]

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.

Effects of n-CPAP

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 before the planned surgical procedure.

Regular use of n-CPAP improves the quality of life for both patients and their bed partners. [82, 83, 84]  The treatment lessens depressive symptoms, and improves daytime functioning, blood pressure and insulin sensitivity. In patients with OSA who receive antihypertensive treatment, long-term CPAP was found to be responsible for a significant reduction of diastolic blood pressure. Asthmatic OSA patients have fewer nighttime symptoms. [85, 75, 86]

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. [12]

Patients with OSA often have increased arterial stiffness and sympathovagal imbalance. CPAP therapy is reported to have beneficial effects on the vascular function in such patients: improvement of the sympathovagal balance by CPAP therapy may be significantly related to decreased stiffness of the central to middle-sized arteries, independent of the changes in the blood pressure and vascular endothelial status. [87]

Repetitive obstructive apnea produces acute impairment of left ventricular longitudinal function, suggesting the development of subendocardial ischemia. CPAP therapy not only decreases the severity of OSA but also ameliorates sleep-induced longitudinal left ventricular dysfunction.

Problems with n-CPAP

One problem with n-CPAP is that although this modality provides good improvement in symptoms and physiologic parameters, compliance with treatment is not good, with regular use sometimes estimated as low as 30% (46% in one study defining use as at least 4 hours/day, 5 days/week). Noncompliance has been classified by Zoula et al into the following categories [88] :

  • Tolerance problems
  • Psychological problems
  • 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. [82]  Psychological problems include lack of motivation, claustrophobia, and anxiety. The suggestions below for dealing with some of these problems may assist the physician in improving treatment compliance.

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 device. 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 n-CPAP.

Some patients have trouble tolerating the initial pressure. Especially when higher pressures (>12-13 cm H2O) are required for elimination of apneas and hypopneas, this level of pressure may be uncomfortable. Many n-CPAP machines have a built-in ramp or gradual increase in pressure. With 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 time. Full pressure is not used until the patient is actually asleep.

Patients may experience 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 of determining whether sufficient potentially reversible mucosal edema exists to warrant pursuing that avenue of treatment is to perform 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 inline humidification and warming of the inspired air may alleviate patient discomfort. [89, 90]

A number of patients report 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.

Patients may experience 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.

Patients may sleep with the 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. [91]

Patients may experience epistaxis. This may be related to the high-flow dry air and may be helped by humidification and warming of the inspired air.

Some patients experience nasal drying. Forced dry air can be irritating to the nose, encouraging mucosal inflammation and crusting. Use of humidified air for n-CPAP usually eliminates this problem.

Other problems may also occur. Pneumopericardium has been reported with n-CPAP. [92]  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.

Rigorous patient education and early reinforcing follow-up may improve long-term use of n-CPAP.

Other considerations

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 a level that barely overcomes 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 they do the one-level n-CPAP device, which delivers the higher pressure throughout the entire respiratory cycle.

Following treatment with CPAP, some patients with OSA remain sleepy despite effective CPAP, and attention should be paid to other diagnoses that can be associated to sleepiness. So-called post-CPAP sleepiness, as a specific disorder, may not exist.

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Oxygen Administration

Because some of the effects of 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 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 n-CPAP.

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Pharmacotherapy

Protriptyline

Protriptyline, a tricyclic antidepressant, is the medication most studied in the treatment of SDB and does yield improvement in patients with this condition. This effect, however, appears to be mainly due to suppression of rapid-eye-movement (REM) sleep. Because SDB is often most severe during REM sleep, less REM sleep can mean fewer apneas.

Modafinil

Modafinil is a wake-promoting medication used in association with CPAP to treat patients with OSAS. It has an action similar to that of sympathomimetic agents (like amphetamine and methylphenidate), though its 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. Because there is no benefit to using modafinil in patients with OSA who are not compliant with CPAP, it should not be administrated in such cases.

Other drugs

Other drugs that have been investigated for treatment of sleep apnea include progestational agents, aminophylline, acetazolamide, L-tryptophan, naloxone, baclofen, bromocriptine, chlorimipramine, and prochlorperazine. For the most part, these have not shown a consistently helpful effect on SDB. However, a study of the use of acetazolamide in patients with OSA and comorbid hypertension found that this agent reduced blood pressure, vascular stiffness, and SDB in this setting. [93]

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Surgical Therapy

Surgical care of SDB is discussed more fully in Surgical Approach to Snoring and Sleep Apnea. [94, 95, 63]  In the perioperative period, n-CPAP is often used to ensure good ventilation even in the presence of postoperative 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 before surgery.

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Diet

Diet and exercise counseling play a major role in the initial therapy for SDB.

Weight reduction in the patient with obesity can dramatically improve SDB. Even a modest weight loss can have quite a beneficial effect on the frequency of apneas and hypopneas. 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; thus, retesting is recommended.

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Consultations

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

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Long-Term Monitoring

It msut be remembered that n-CPAP does not cure or alter the underlying 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, PSG results on the first day or two off n-CPAP look remarkably improved. However, this carry-over is short-lived, and it is usually the case that within 1 week, the snoring, apneas, hypoxias, and daytime symptoms return to their original level.

n-CPAP is highly successful in managing OSA, as long as it is used. Unfortunately, compliance with n-CPAP use is less than ideal: Only about half of the patients for whom it is prescribed use it for at least 4 hours a night on 5 of 7 nights. 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 n-CPAP for years. Others find sustained use impossible; these are the patients for whom surgery may be helpful. [63]

Even snorers whose PSG does not show SDB should be monitored periodically because they can progress to SDB with time, even without weight gain.

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