Apnea

Apnea is strictly defined as the absence of breathing. The term is also used to refer to an interruption in breathing that occurs in some infants and during the sleep of some children and adults.

Apnea in Infants

The usual cause of apnea in infants is immaturity of the brain centers that regulate breathing. From time to time, the infant suddenly stops breathing completely and turns blue. If the baby is stimulated in some way (for example, by a flick of the finger on the bottom of the foot), he or she will usually start breathing normally at once.

Seldom is it necessary to use first-aid measures or a mechanical respirator to restart breathing. However, because a history of apnea is one of the factors that may be associated with sudden infant death syndrome (SIDS), physicians sometimes recommend monitoring high-risk infants with equipment that sounds an alarm if any stoppage of breathing is detected. In some cases, the tendency toward apnea disappears a few weeks after birth, when the breathing control centers have matured.

Apnea in Children and Adults

Apnea in children and adults is generally less immediately life-threatening than apnea in infants, but it can be physically exhausting and, in a severe form, can cause cardiovascular and respiratory problems. In some patients, episodes of sleep apnea can cause the concentration of carbon dioxide in the blood to build up to a dangerously high level.

Recognition of the problem generally cannot be made by the patient. A spouse or parent may be the first to notice an abnormal sleep pattern -- for example, loud snoring that is followed by silence (when the breathing stops) and then a loud choke or gasp as the sleeper partially awakens, clears the air passage, and resumes breathing.

This type of pattern may be repeated many times during the night. As a result, people with sleep apnea are likely to be drowsy during the day and irritable due to lack of sleep, with decreased memory and attention span. A definitive diagnosis can be made after observation in a hospital sleep laboratory.

In children and adults, apnea may occur because of a disorder in the breathing control centers in the brain, or it may be a result of physical abnormalities of the chest, neck, and back due to obesity, the presence of a disease, or an inborn structural defect. The most common treatment for adult sleep apnea is a device called continuous positive airway pressure (CPAP).

With CPAP, a mask is worn over the nose and mouth; air is forced through the mask to keep the airways open while the individual is sleeping. If apnea is due to an abnormality of the breathing control centers, drugs may be prescribed or stimulation of the diaphragm (the large muscle separating the chest and abdominal cavities, which is instrumental in breathing) with an electronic pacemaker may be tried.

Obesity is a common cause of sleep apnea in adults, because the presence of excess tissue can block the airway in certain sleeping positions; the disorder may disappear after weight loss. If a physical abnormality due to disease or a structural defect is the cause, surgical treatment may be necessary. For example, enlarged tonsils and adenoids that are partially obstructing the upper airway may be removed. In extreme cases, the only solution may be tracheostomy (surgical creation of a hole in the trachea and neck, through which the patient can breathe).