What is apnea?

Causes and Symptoms

People normally experience brief pauses in breathing.
When these pauses last more than twenty seconds or are accompanied by bradycardia (slow heart rate) or cyanosis
(bluish skin from poor blood oxygenation), however, they can be life threatening. This condition is referred to as apnea.

Apnea can be categorized into three types based on whether inspiratory muscle activity is present. In central apnea, which has a neurological cause, there is no activity of inspiratory muscles following expiration. Central apnea is uncommon except in cases of prematurity in infants. Obstructive apnea, the most common type, occurs when the person is making an effort to breathe, so inspiratory muscles are moving. As a result of a blockage, however, air cannot flow into or out of the person’s nose or mouth. This condition typically occurs while the patient is asleep and is characterized by snoring, gasping for air, or stridor (noisy breathing). It is seen in people who have a physical obstruction in the airway, who experience gastroesophageal reflux, or who are overweight. The third type of apnea is mixed apnea, which is a combination of central and obstructive apnea. It is usually seen in young children and can occur while asleep or awake.

Individuals with apnea will often show decreases in heart rate, oxygen saturation, peripheral blood flow, and muscle tone. Adults suffering from sleep
apnea may exhibit depression, irritability, learning difficulty, and sleepiness during the day. With sleep apnea, there can be up to sixty apneic episodes per hour, with snoring or choking in between.

All forms of apnea can be diagnosed by electrophysiological testing. Pneumograms are often done on premature babies to record their pattern of breathing over a twelve-hour period. Polysomnography is used for older children and adults to record electrical activity of the brain, muscle activity, heart rate, airflow, oxygen levels in the body, and eye movement.

Treatment and Therapy

The treatment of apnea can be based on medication, mechanical treatment, or surgery. The category of drugs used to treat apnea is xanthines. Mechanical treatment involves the use of continuous positive airway pressure (CPAP), a mask worn over the nose during sleep that forces air through the nasal passages. Another potential treatment involves the use of a mandibular advancement device (MAD), a specially designed and fitted oral appliance that prevents obstruction of the throat during sleep. Surgery may be performed to remove an obstruction or to increase the size of the airway. Overweight patients are often encouraged to exercise and improve their diet.

Perspective and Prospects

Studies have indicated that people with obstructive sleep apnea have less gray matter in their brains. Research is being done to determine if the lack of gray matter leads to the apnea or the lack of oxygen caused by apnea causes deterioration in the brain.

Bibliography:

George, Ronald B. Current Pulmonology and Critical Care Medicine. Vol. 17. Philadelphia: Mosby, 1996.

Klaus, Marshall H., and Avroy A. Fanaroff, eds. Care of the High-Risk Neonate. 5th ed. Philadelphia: W. B. Saunders, 2001.

Pack, Allan, ed. Sleep Apnea: Pathogenesis, Diagnosis, and Treatment. 2d ed. New York: Marcel Dekker, 2008.

“Sleep Apnea.” MedlinePlus, Apr. 19, 2013.

White, Emily, Thomas Workman, Amir Sharafkhaneh, and Michael Fordis. “Treating Sleep Apnea: A Review of the Research for Adults.” Agency for Healthcare Research and Quality, Aug. 8, 2011.