Sleep Apnea

(Sleep-Disordered Breathing)

Sleep apnea is intermittent interruption of breathing during sleep; if untreated, sleep apnea can cause significant morbidity, which is typically cardiopulmonary (eg, pulmonary hypertension, arrhythmias, heart failure), and mortality.

Sleep apnea may be obstructive, central, or mixed (a combination).

Central Sleep Apnea

Central sleep apnea is temporary interruption of breathing during sleep due to loss of central respiratory drive.

Common causes in the elderly include neurologic disorders (eg, stroke, Alzheimer's disease), heart failure, and uremia. Use of certain drugs (eg, sedative-hypnotics, alcohol) may further depress respiration. The typical symptom is Cheyne-Stokes breathing.

The underlying disorder should be treated when possible (eg, severity of heart failure should be reduced). However, whether central sleep apnea itself should be treated and what the best treatment is remain unclear. Some experts recommend nighttime O₂ therapy to provide short-term relief and, used with continuous positive airway pressure, possibly to improve long-term outcomes.

Obstructive Sleep Apnea

Obstructive sleep apnea is intermittent interruption of breathing during sleep due to airway obstruction. Obstructive sleep apnea causes pulmonary hypertension and can contribute to cardiac and vascular complications. Symptoms include intermittent loud snoring, choking, and apnea. Diagnosis is by polysomnography done during sleep. Treatment may involve avoidance of alcohol and of drugs that depress respiration, as well as weight loss, nasal continuous positive airway pressure, and, occasionally, tracheostomy or other surgery.

Geriatric Essentials

• Obstructive sleep apnea is common, can cause serious preventable complications, and is often undiagnosed.
• The major risk factors for obstructive sleep apnea in younger adults (male sex, obesity, and large neck circumference) are less predictive in the elderly. However, obesity is still a risk factor.

Obstructive sleep apnea is the most common type of sleep apnea in the elderly as well as in younger adults. Mild obstructive sleep apnea occurs in about 24% of elderly people who live independently, 33% of those in acute care institutions, and 42% of those in nursing homes.

Airway obstruction results from temporary collapse of the oropharyngeal wall. The cause of obstructive sleep apnea in the elderly is unknown. Risk factors that are moderately to strongly predictive in young adults (male sex, obesity, and large neck circumference) are only weakly predictive in the elderly. Thus, disease etiology and pathophysiology may differ in the elderly. Use of sedative-hypnotics or large amounts of alcohol may precipitate or exacerbate obstructive sleep apnea; these substances may relax upper airway neck muscles, decreasing the diameter of the upper airway temporarily at night, and may depress central respiratory drive, decreasing efforts to overcome airway obstruction.

Airway obstruction may be partial (hypopnea) or complete (apnea); because brief episodes of either can occur physiologically, episodes are considered abnormal only if they last >= 10 sec. Episodes may cause severe O₂ desaturation, sometimes with systemic and pulmonary hypertension. Complications can include various arrhythmias, ischemic heart disease, permanent systemic or pulmonary hypertension, stroke, depression, dementia, and erectile dysfunction. Premature death can occur.

Symptoms and Signs

Breathing becomes abnormally slow and shallow or stops. During these episodes, patients make persistent diaphragmatic efforts to overcome the airway obstruction, resulting in cacophonous snoring, grunting, or choking. A bed partner usually notices these efforts, but patients may not remember them. The bed partner may also notice that breathing stops after a period of crescendo snoring. To resume normal breathing, patients awaken repeatedly (usually unknowingly) and spend excessive proportions of sleep in lighter NREM stages; as a result, sleep is not refreshing, and patients are restless, groggy, and mentally dull during the day.

Diagnosis

Snoring or moderate or intermittent daytime sleepiness alone usually does not indicate obstructive sleep apnea; both are common among the elderly. The diagnosis is more likely when a patient's bed partner reports more characteristic symptoms during sleep: frequent, severe snoring, particularly with a crescendo pattern; abnormally slow or interrupted breathing; or choking. Other reasons to test for obstructive sleep apnea are controversial but may include unexplained hypertension or right ventricular failure or hypertrophy, a large neck circumference, and unexplained excessive daytime sleepiness, especially in obese patients. A combination of obesity, sleepiness, snoring, and hypertension may suggest the disorder.

The diagnosis can be confirmed by overnight polysomnography, usually done in a sleep laboratory; however, polysomnography is expensive and not widely available. Ambulatory (in-home) polysomnography is becoming more available and can be used instead. The apnea-hypopnea index is the number of hypopneic and apneic episodes lasting >= 10 sec that occur per hour; it is used to classify obstructive sleep apnea as absent (< 5), mild (5 to 15), moderate (15 to 30), or severe (> 30). Severity of disease predicts severity of symptoms and complications.

In the elderly, most cases are not diagnosed. Clinicians may be unaware of the prevalence, symptoms, or consequences of the disorder, and risk factors in the elderly are not clear. Thus, the diagnosis may not be considered. It is particularly easy to miss if a bed partner is unavailable or cannot provide information. Even if the diagnosis is considered, polysomnography, because it is not widely available, may not be used unless the diagnosis is strongly suspected.

Treatment

Treatment begins with common sense measures to reduce risk (eg, gradual discontinuation of sedative-hypnotics, moderation of alcohol intake). For overweight patients, reasonable efforts to lose weight are recommended.

Next, local treatment aims to mechanically overcome airway obstruction. Nasal continuous positive airway pressure (CPAP) therapy is the treatment of choice; it is usually effective but must be continued indefinitely. When CPAP is begun, patients should be encouraged to use it regularly each night because early adherence may make long-term adherence more likely. Dental devices that help keep the airway open may be useful, especially for patients who have mild symptoms or who cannot tolerate CPAP. Tracheostomy may be permanently effective but is reserved for severe disease.

Uvulopalatopharyngoplasty (removal of excess tissue to enlarge the pharyngeal airspace) helps < 50% of patients and may not be effective long-term. Laser surgery to reduce or obliterate pharyngeal tissue is not very effective; it alleviates snoring but may not reduce the number of apneic episodes.

This topic was last updated March 2006.