Obstructive Sleep Apnea (OSA)

Less severe forms may not produce oxygen desaturation, but they interrupt sleep.

Obstructive sleep hypopnea is a condition in which inspiratory flow is diminished, but not absent, in a high resistance airway.

Upper airway resistance syndrome is crescendo snoring terminated by snorts and respiratory effort-related arousals (RERAs). Breathing reductions do not meet strict criteria for obstructive apneas and hypopneas. Patients with upper airway resistance syndrome are typically younger and have less obesity than those with OSA. Patients are more often female, report fatigue, and complain of insomnia. Snoring and upper airway airflow resistance cause noisy inspiration but without arousals from sleep lasting > 2 seconds. Symptoms, diagnostic evaluation, and treatment of snoring and upper airway resistance syndrome are similar to those of OSA.

Obstructive sleep apnea is the leading medical cause of excessive daytime sleepiness. A more correct term is wake-time excessive sleepiness, because people who work during the night may be excessively sleepy during night hours. The excessive sleepiness actively increases risk of automobile crashes, difficulties at work, and sexual dysfunction. There is often some degree of cognitive impairment and also increased risk of injury (eg, when operating heavy machinery or engaging in other activities during which unintentional sleep episodes would be hazardous). Relationships with bed partners, roommates, and/or housemates may also be adversely affected because such people may have difficulty sleeping because of the patient's noisy, restless sleep. Severe OSA (apnea-hypopnea index > 30 per hour) increases the risk of death in middle-aged men.

OSA also has medical risks unrelated to excessive sleepiness. Hypertension is strongly associated with OSA (2 Pathophysiology references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ). Normotensive patients with untreated OSA are more likely to develop hypertension within 5 years of diagnosis. Repetitive nocturnal hypoxia and sleep disruption are associated with increased risk of medical disorders, including heart failure Heart Failure (HF) Heart failure (HF) is a syndrome of ventricular dysfunction. Left ventricular (LV) failure causes shortness of breath and fatigue, and right ventricular (RV) failure causes peripheral and abdominal... read more , atrial fibrillation Atrial Fibrillation Atrial fibrillation is a rapid, irregularly irregular atrial rhythm. Symptoms include palpitations and sometimes weakness, effort intolerance, dyspnea, and presyncope. Atrial thrombi may form... read more (even after catheter ablation) and other arrhythmias, nonalcoholic fatty liver Metabolic Dysfunction–Associated Liver Disease (MASLD) Steatotic liver disease is due to excessive accumulation of lipid in hepatocytes. Metabolic dysfunction–associated liver disease (MASLD) includes simple fatty infiltration (a benign condition... read more , and stroke Overview of Stroke Strokes are a heterogeneous group of disorders involving sudden, focal interruption of cerebral blood flow that causes neurologic deficit. Strokes can be Ischemic (80%), typically resulting... read more (3 Pathophysiology references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ). The risk of stroke and all-cause mortality is increased even when controlling for other risk factors (eg, hypertension Hypertension Hypertension is sustained elevation of resting systolic blood pressure (≥ 130 mm Hg), diastolic blood pressure (≥ 80 mm Hg), or both. Hypertension with no known cause (primary; formerly, essential... read more , diabetes Diabetes Mellitus (DM) Diabetes mellitus is impaired insulin secretion and variable degrees of peripheral insulin resistance leading to hyperglycemia. Early symptoms are related to hyperglycemia and include polydipsia... read more ) (4 Pathophysiology references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ). However, the contribution of OSA to these common disorders (and thus its cost to society) is often underappreciated (5 Pathophysiology references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ).

In addition, perioperative complications, including cardiac arrest, occur with unrecognized OSA, because moderate and general anesthesia is a risk for airway obstruction. Patients should inform an anesthesiologist of the diagnosis before undergoing any surgery and should receive continuous positive airway pressure (CPAP) when they receive preoperative drugs and during recovery.

Sleep studies include

Polysomnography Testing Almost half of all people in the US report sleep-related problems. Disordered sleep can cause emotional disturbance, memory difficulty, poor motor skills, decreased work efficiency, and increased... read more records and helps classify stages of sleep and the occurrence and duration of apneic and hypopneic periods. It is ideal for confirming the diagnosis of OSA and quantifying the severity of OSA. However, it requires an overnight stay in a sleep laboratory and is thus complicated and expensive. Polysomnography typically includes

The patient is also observed by video.

Other variables evaluated include limb muscle activity (to assess nonrespiratory causes of sleep arousal, such as restless legs syndrome and periodic limb movements disorder) and body position, because apnea may occur predominantly in the supine position.

The apnea-hypopnea index (AHI) is the total number of episodes of apnea and hypopnea occurring during sleep divided by the hours of sleep time. It is a common measure of respiratory disturbance during sleep and is used to classify the severity of OSA. Note the AHI alone does not determine need for treatment.

OSA is graded as:

Some patients may have a very high AHI (> 60).

The respiratory disturbance index (RDI) is a related measure that includes the number of arousals related to respiratory effort (called respiratory effort-related arousals or RERAs) plus the number of apnea and hypopnea episodes per hour of sleep.

The arousal index, which is the number of arousals per hour of sleep, can be computed if EEG monitoring is used. The arousal index is loosely correlated with the apnea-hypopnea index and respiratory disturbance index; about 20% of apneas and desaturation episodes are not accompanied by arousals, or other causes of arousals are present.

However, the apnea-hypopnea index, arousal index, and respiratory disturbance index are only moderately associated with a patient’s symptoms. Some patients with a high or extremely high AHI (eg, > 60) have few or no symptoms. Additional metrics and combinations of metrics may prove useful in diagnosis (6 Diagnosis references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ). Furthermore, studies now show that it is a composite of clinical and polysomnographic data (not just AHI) that are linked to outcome and to cardiovascular risk and mortality, for instance, sleepiness regardless of AHI is linked to excess cardiovascular disease.

Home sleep testing using portable diagnostic tools uses a limited subset of polysomnographic measures, typically just heart rate, pulse oximetry, respiratory effort, position, and nasal airflow to detect apnea and estimate its severity. Their role is expanding (7 Diagnosis references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ) because of their convenience and decreased cost and their ability to provide a reasonably accurate estimate of respiratory disturbances during sleep.

However, portable tools have some limitations. They do not actually detect the presence of sleep and instead depend on patients to self-report sleeping, which can be inaccurate; if patients were not sleeping during part of the study and they did not report this, sleep-disordered breathing will be underestimated. Also, coexisting sleep disorders (eg, restless legs syndrome Periodic Limb Movement Disorder (PLMD) and Restless Legs Syndrome (RLS) Periodic limb movement disorder (PLMD) and restless legs syndrome (RLS) are characterized by abnormal motions of and, for RLS, usually sensations in the lower or upper extremities, which may... read more , seizures, REM behavior disorder, confusional arousals) are not detected. Follow-up polysomnography may still be needed to characterize these disorders as well as to accurately provide AHI and RDI values in the different stages of sleep and with changes in position, especially when surgery or therapy other than positive airway pressure is being considered.

Portable tools are often used in combination with questionnaires (eg, STOP-Bang, Berlin Questionnaire). If questionnaire results indicate a higher pre-test probability of disease, the sensitivity and specificity of the portable tools is higher.

Initial treatment aims to control risk factors such as obesity, hypertension, alcohol use, and sedative use. Exercise decreases the AHI and increases alertness, independent of any effect on body mass index (BMI).

Daytime sleepiness can be reduced by good sleep hygiene measures Insomnia and Excessive Daytime Sleepiness (EDS) Many sleep disorders manifest with insomnia and usually excessive daytime sleepiness (EDS). Insomnia is difficulty falling or staying asleep, early awakening, or a sensation of unrefreshing... read more , including sleeping longer and discontinuing sedative drugs, particularly antihistamines or antidepressants.

Modest weight loss (≥ 15%) may result in clinically meaningful improvement (2 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more , 3 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ) but should not be considered curative for OSA. However, weight loss Treatment Obesity is excess body weight, defined as a body mass index (BMI) of ≥ 30 kg/m². Complications include cardiovascular disorders (particularly in people with excess abdominal fat)... read more is extremely difficult for most people, especially those who are fatigued or sleepy. Bariatric surgery Bariatric Surgery Bariatric surgery is the surgical alteration of the stomach, intestine, or both to cause weight loss. In the US, about 250,000 bariatric operations are done in each year. Development of safer... read more , however performed, is an option that frequently reverses symptoms and improves AHI in 85% of OSA patients with severe obesity (BMI ≥ 40); however, the degree of improvement may not be as great as the degree of weight loss.

CPAP is the treatment of choice for most patients with OSA and subjective daytime sleepiness, including those in whom it causes cognitive impairment (4 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more , 5 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ). There are reports of racial and socioeconomic bias in making this treatment available.

There are many different CPAP devices available, including those that cover the nose, nose and mouth, or the whole face. All have cushions to provide an air seal, which is essential for maintaining a pressure gradient. Cushions may be inflatable or made of silicone, foam, or gel. Proper fit and comfort vary widely among patients but must be optimized for both efficacy and adherence.

CPAP improves upper airway patency by applying positive pressure to the collapsible upper airway segment. Effective pressures typically range from 3 to 15 cm H2O. Pressure requirements are not correlated with disease severity. Many CPAP devices monitor CPAP efficacy and titrate pressures automatically, according to internal algorithms. If necessary, polysomnographic monitoring can be used to guide manual titration of pressure.

Although a reduction in AHI is one of the treatment goals, CPAP will reduce cognitive impairment and improve quality of life regardless of improvement in the AHI. CPAP also may reduce blood pressure. If CPAP is withdrawn, symptoms recur over several days, though short interruptions of therapy for acute medical conditions are usually well tolerated. Duration of therapy is indefinite.

If clinical improvement is not apparent, CPAP adherence should be reviewed, and patients should be reassessed for a second sleep disorder (eg, upper airway obstruction) or a comorbid disorder. If patients have septal deviation or polyps, nasal surgery may make CPAP treatment more successful but inconsistently “treats” OSA.

Adverse effects of nasal CPAP include discomfort resulting from a poorly fitting mask, and dryness and nasal irritation, which can be alleviated in some cases with the use of warm humidified air. However, newer mask designs have improved comfort and ease of use.

Adherence is difficult for many people and is lower in patients who do not experience sleepiness. Overall, about 50% of patients adhere to use of CPAP long term. Adherence can be improved by efforts to foster a positive attitude towards device use combined with early attention to any problems, particularly mask fit, and close follow-up by a committed caretaker, with reinforcement by the primary care physician. There is also a need to recognize and address the decreased long-term CPAP adherence among patients who do not have obesity and have low respiratory arousal threshold (ie, awaken easily) and thus a propensity for increased arousals and irregular breathing.

Even when adherence is adequate, results may become unsatisfactory if patient factors change (eg, weight gain, nasal obstruction develops).

CPAP can be augmented with inspiratory assistance (bilevel positive airway pressure) to increase tidal volume in patients with comorbid obesity-hypoventilation syndrome.

Oral appliances are designed to advance the mandible or, at the very least, prevent retrusion and tongue prolapse during sleep (6 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more , 7 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more , 8 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ). Some appliances are designed to pull the tongue forward. These appliances are now considered mainstream treatments of both snoring and mild to moderate OSA. Comparisons of appliances to CPAP show equivalent effectiveness in mild to moderate OSA, but cost-effectiveness studies are focused on fixed initial costs of fabrication, rather than replacement and follow-up costs.

Surgical procedures to correct anatomic factors, such as enlarged tonsils and nasal polyps contributing to upper airway obstruction (called anatomic procedures), should be considered (8 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more , 9 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ). Surgery for macroglossia or micrognathia is also an option. Surgery is a first-line treatment if specific anatomic encroachment is identified. However, in the absence of encroachment, evidence to support surgery as a first-line treatment is lacking.

Uvulopalatopharyngoplasty (UPPP) was previously the most common procedure. It involves resection of pharyngeal tissue. UPPP has been largely replaced by less aggressive approaches that attempt to stabilize the lateral walls of the pharynx and/or enlarge the velopharyngeal area without risk of altering speech or swallowing. Equivalence with CPAP was shown in one study using CPAP as a bridge to surgery, but the interventions have not been directly compared. Results are less predictable in patients who have severe obesity or anatomic narrowing of the airway. The procedure may reduce intrusive snoring, although apneic episodes may remain as severe (although silent) as before surgical intervention.

Other surgical procedures include midline glossectomy, hyoid advancement, and mandibulomaxillary advancement. Mandibulomaxillary advancement is sometimes offered as a 2nd-stage procedure if soft tissue approaches are not curative. The optimal multistage approach is not known.

Tracheostomy is the most effective therapeutic maneuver for OSA but is done as a last resort. It bypasses the site of obstruction and is indicated for patients most severely affected (eg, those with cor pulmonale Cor Pulmonale Cor pulmonale is right ventricular (RV) enlargement secondary to a lung disorder that causes pulmonary artery hypertension. Right ventricular failure follows. Findings include peripheral edema... read more ).

Upper airway stimulation using an implanted device to stimulate a branch of the hypoglossal nerve (10 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more , 11 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ) can activate muscles that protrude the tongue and other muscles that help open the airway. This therapy is now mainstream, being successful in selected patients with moderate to severe disease. It is used mainly in those who are unable to tolerate CPAP therapy and in whom oral appliances are ineffective. The procedure may also be tried in those in whom mandibulomaxillary advancement is contemplated. Improvements in AHI to < 10 per hour occur in about 65% of these selected patients, but symptoms may improve without achieving efficacy in an AHI < 20 per hour.

Various adjunctive treatments are sometimes used but have no proven benefit for OSA.

Supplemental oxygen improves blood oxygenation and may reduce AHI and arousal index among patients who did not respond to upper airway surgery (12 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ), but a beneficial clinical effect is mainly in those with high gain (tendency to have repeated apnea or hypopnea after an initial episode) and effects are hard to predict. Also, oxygen may provoke respiratory acidosis and morning headache.

Alerting drugs (eg, modafinil, solriamfetol) may be used to counteract excessive sleepiness that occurs with OSA or in the 20% of treated patients who have residual sleepiness (13 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more , 14 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more , 15 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ).

A number of other drugs have been tried, including tricyclic antidepressants, theophylline, dronabinol, combined atomoxetine plus oxybutynin (16 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ), but cannot be recommended because of factors including limited experience, a low therapeutic index, lack of replication of results, and lack of adequate trials. Better methods to recognize sleep apnea subtypes may allow better selection of patients for this line of treatment.

Exercises for upper airway muscles (myofunctional therapy) have been proposed on the theory that improved muscle strength and tone might help improve airway patency during sleep (17 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ). There are a number of exercises that seem to reduce AHI and symptoms, making this approach interesting, particularly because it is noninvasive and with no adverse effects. However, this approach is not yet a mainstream recommendation, because of the wide variety of techniques proposed and the uncertainly about their mechanism of action and efficacy, combined with the great practical difficulties with adherence.

Nasal dilatory devices and throat sprays sold over-the-counter for snoring have not been studied sufficiently to prove value in OSA.

Laser-assisted uvuloplasty, uvular splints, and radiofrequency tissue ablation have been used to treat snoring in patients without OSA. Although they may transiently decrease snoring loudness, efficacy in treating OSA is neither predictable nor durable.

An informed patient and family are better able to cope with an OSA treatment strategy, including tracheostomy. Patient support groups provide helpful information and effectively support timely treatment and follow-up. There is now organized investigation on the role of patient support groups and digital support tools for management (18 Treatment references Obstructive sleep apnea (OSA) consists of multiple episodes of partial or complete closure of the upper airway that occur during sleep and lead to breathing cessation (defined as a period of... read more ).