Apnea episodes may occur in premature newborns if the part of their brain that controls breathing (respiratory center) has not matured fully.
Apnea may lower the amount of oxygen in the blood, resulting in a slow heart rate and bluish lips and/or skin.
This disorder is diagnosed by observation or by the alarm of a monitor attached to the newborn.
As the respiratory center of the brain matures, apnea episodes become less frequent and then stop altogether.
If gentle prodding does not cause the newborn to resume breathing, artificial respiration may be needed.
Newborns with significant apnea are given caffeine, along with other treatments, to stimulate breathing.
(See also Overview of General Problems in Newborns Overview of General Problems in Newborns Problems in newborns may develop Before birth while the fetus is growing During labor and delivery After birth About 10% of newborns need special care after birth due to prematurity, problems... read more .)
Apnea of prematurity commonly occurs in about 25% of infants who are born prematurely Gestational age Problems in newborns may develop Before birth while the fetus is growing During labor and delivery After birth About 10% of newborns need special care after birth due to prematurity, problems... read more (delivered before 37 weeks of gestation Gestational age Problems in newborns may develop Before birth while the fetus is growing During labor and delivery After birth About 10% of newborns need special care after birth due to prematurity, problems... read more ). Apnea of prematurity is often more frequent and more severe the more premature a baby is. This disorder usually begins 2 to 3 days after birth and only rarely on the first day. In apnea of prematurity, newborns may have repeated episodes of normal breathing alternating with brief pauses in breathing. In some premature babies, the pause in breathing may not last 20 seconds but does cause a decrease in the heart rate or in the amount of oxygen in the blood. Shorter pauses in breathing that cause decreases in heart rate or blood oxygen levels are still considered apnea of prematurity.
There are three types of apnea:
Central apnea occurs when the part of the brain that controls breathing ( respiratory center Control of Breathing Breathing is usually automatic, controlled subconsciously by the respiratory center at the base of the brain. Breathing continues during sleep and usually even when a person is unconscious.... read more ) is not functioning properly because it has not matured fully. This is the most common type of apnea of prematurity.
Obstructive apnea is caused by temporary blockage of the throat (pharynx) due to low muscle tone or a bending forward of the neck. This type may occur in full-term babies as well as those born prematurely.
Mixed apnea is a combination of central apnea and obstructive apnea.
In all types of apnea, the heart rate can become slow and levels of oxygen can decrease.
Not all pauses in breathing are problems. Periodic breathing is 5 to 20 seconds of normal breathing followed by periods of apnea that last less than 20 seconds. Periodic breathing is common among premature newborns and is not considered apnea of prematurity. Full-term newborns can also have periodic breathing. It does not cause the heart rate or oxygen levels to drop and usually does not cause other problems.
Symptoms of Apnea of Prematurity
In the hospital, premature newborns are routinely attached to a monitor that sounds an alarm if they stop breathing for 20 seconds or more or if their heart rate slows. Depending on the length of the episodes, pauses in breathing may decrease the oxygen levels in the blood, which results in a bluish discoloration of the skin and/or lips ( cyanosis Cyanosis Cyanosis is a bluish discoloration of the skin resulting from an inadequate amount of oxygen in the blood. Cyanosis occurs when oxygen-depleted (deoxygenated) blood, which is bluish rather than... read more ) or pale skin (pallor). Low levels of oxygen in the blood may then slow the heart rate (bradycardia).
Diagnosis of Apnea of Prematurity
Observation or monitor alarm
Other causes ruled out
The diagnosis of apnea is usually made by observing the newborn breathe or by hearing the alarm of a monitor attached to the newborn and noting no breathing movements when the newborn is checked.
Apnea can sometimes be a sign of a disorder, such as infection in the blood ( sepsis Sepsis in Newborns Sepsis is a serious bodywide reaction to infection spread through the blood. Newborns with sepsis appear generally ill—they are listless, do not feed well, often have a gray color, and may have... read more ), low blood sugar ( hypoglycemia Hypoglycemia Diabetes mellitus is a disorder in which blood sugar (glucose) levels are abnormally high because the body does not produce enough insulin or fails to respond normally to the insulin produced... read more ), or a low body temperature ( hypothermia Hypothermia Hypothermia is a dangerously low body temperature. Hypothermia is often regarded as a cold injury, because it can be caused or made worse by exposure to cold surroundings. Being in an environment... read more ). Therefore, doctors evaluate the newborn to rule out these causes when apnea begins suddenly or unexpectedly or the frequency of apnea episodes increases. Doctors may take samples of blood, urine, and cerebrospinal fluid to test for serious infections and test blood samples to determine whether the level of blood sugar is too low.
Prognosis for Apnea of Prematurity
Over time, as the respiratory center matures, episodes of apnea become less frequent, and by the time the newborn approaches 37 weeks of gestation Gestational age Problems in newborns may develop Before birth while the fetus is growing During labor and delivery After birth About 10% of newborns need special care after birth due to prematurity, problems... read more , the episodes usually no longer occur. Apnea may continue for weeks in infants who were born extremely prematurely (such as at 23 to 27 weeks). Apnea of prematurity rarely causes death.
Although premature birth is a risk factor for sudden infant death syndrome Sudden Infant Death Syndrome (SIDS) Sudden infant death syndrome is the sudden, unexpected death, usually during sleep, of a seemingly healthy infant 1 year of age or younger. The cause of sudden infant death syndrome (SIDS) is... read more (SIDS), an association between apnea of prematurity and a later risk of SIDS has not been proved. Likewise, there is no proof that discharging a premature newborn from the hospital with an apnea monitor decreases the risk of SIDS.
Treatment of Apnea of Prematurity
Gentle prodding or touching
Treatment of cause
Measures to support breathing
When apnea is noticed, either by observation or monitor alarm, newborns are touched or prodded gently to stimulate breathing, which may be all that is required.
Further treatment of apnea depends on the cause. Doctors treat known causes such as infections.
If episodes of apnea become frequent, and especially if newborns have cyanosis, they remain in the neonatal intensive care unit Neonatal intensive care unit (NICU) Problems in newborns may develop Before birth while the fetus is growing During labor and delivery After birth About 10% of newborns need special care after birth due to prematurity, problems... read more (NICU). They may be treated with a drug that stimulates the respiratory center, such as caffeine. If this treatment does not prevent frequent and severe episodes of apnea, newborns may need treatment with continuous positive airway pressure Obstructive sleep apnea (CPAP). This technique allows newborns to breathe on their own while receiving slightly pressurized oxygen or air given through prongs placed in the nostrils. Newborns who have apnea spells that are difficult to treat may need a ventilator Mechanical Ventilation Mechanical ventilation is use of a machine to aid the movement of air into and out of the lungs. Some people with respiratory failure need a mechanical ventilator (a machine that helps air get... read more (a machine that helps air get in and out of the lungs) to help them breathe.
Newborns should always be placed on their back to sleep. Safe sleeping practices Safe to Sleep: Reducing the Risk of Sudden Infant Death Syndrome should be followed for all infants whether they are premature or not.
Because all premature newborns, especially those with apnea of prematurity, are at risk of apnea, low levels of oxygen in the blood, and a slow heart rate while in a car seat, they should have a car seat challenge test Discharge from the hospital A premature newborn is a baby delivered before 37 weeks of gestation. Depending on when they are born, premature newborns have underdeveloped organs, which may not be ready to function outside... read more before leaving the hospital. This test determines whether the newborn is able to safely ride home in the semi-reclined position of a car seat.
Most newborns are able to go home from the hospital without a monitor, whereas some newborns are sent home with an apnea monitor and may also need caffeine. Parents should be taught how to properly use the monitor and any other equipment, what to do when the alarm sounds, how to do cardiopulmonary resuscitation Standard CPR Cardiac arrest is when the heart stops pumping blood and oxygen to the brain and other organs and tissues. Sometimes a person can be revived after cardiac arrest, particularly if treatment is... read more (CPR) in case it is needed, and how to keep a record of events. Most monitors electronically store information about events that occur. Parents should consult a doctor about when to stop using the monitor.