Apnea
Apnea is defined as a cessation of breathing, originating from the Greek word meaning "without wind." This condition can manifest as brief pauses in breathing, but it becomes life-threatening when these pauses last over twenty seconds or are accompanied by bradycardia (slow heart rate) or cyanosis (bluish skin due to inadequate oxygen). There are three main types of apnea: central apnea, which is rare and has a neurological cause; obstructive apnea, the most common type, caused by airway blockage during sleep; and mixed apnea, which combines elements of both central and obstructive apnea, often seen in young children. Symptoms can include snoring, gasping for air, daytime sleepiness, and may be associated with depression and irritability in adults.
Diagnosis typically involves electrophysiological testing, such as polysomnography, which monitors various bodily functions during sleep. Treatment options vary and may include the use of medications, mechanical devices like continuous positive airway pressure (CPAP) masks, or surgical interventions to facilitate breathing. Additionally, lifestyle changes, especially for overweight individuals, are often recommended. Ongoing research is investigating the relationship between apnea and brain health, particularly concerning gray matter loss associated with the condition. Understanding apnea is crucial for effective management and improving the quality of life for those affected.
Apnea
ANATOMY OR SYSTEM AFFECTED: Brain, lungs, nervous system, respiratory system
DEFINITION: Cessation of breathing, from the Greek meaning “without wind.”
CAUSES: Inspiratory muscle inactivity, airway obstruction
SYMPTOMS: Choking, snoring, gasping, stridor, bradycardia, cyanosis, depression, irritability, learning difficulty, daytime sleepiness
DURATION: Chronic, with multiple episodes during sleep
TREATMENTS: Medication (xanthines), mechanical treatment (continuous positive airway pressure mask), surgery
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 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.
According to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, released in 2022, obstructive sleep apnea is define as having at least five obstructive incidents per hour of sleep, accompanied by snoring, snorting, or grasping for breath, or daytime sleepiness. It is also defined as having at least fifteen obstructive incidents per hour of sleep, regardless of any additional symptoms. 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 in between.
All forms of apnea can be diagnosed by electrophysiological testing. Pneumograms are often done on 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 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
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