Apnea of prematurity
Definition
Apnea means "without breath" and refers to breathing that slows down or stops from any cause. Apnea of prematurity refers to breathing pauses in babies who were born before 37 weeks of pregnancy (premature birth).
Most premature babies have some degree of apnea because the area of the brain that controls breathing is still developing.
Alternative Names
Apnea - newborns; AOP; As and Bs; A/B/D; Blue spell - newborns; Dusky spell - newborns; Spell - newborns; Apnea - neonatal
Causes
There are several reasons why newborns, in particular those who were born early (prematurely), may have apnea, including:
- The brain areas and nerve pathways that control breathing are still developing.
- The muscles that keep the airway open are smaller and not as strong as they will be later in life.
Other stresses in a sick or premature baby may worsen apnea, including:
- Anemia
- Feeding problems
- Heart or lung problems
- Infection
- Low oxygen levels
- Temperature problems
Symptoms
The breathing pattern of newborns is not always regular and may be called "periodic breathing." This pattern is even more likely in newborns born early. It consists of episodes of either shallow breathing or short pauses in breathing lasting just a few seconds. These episodes are then followed by periods of regular breathing. This is generally considered a normal pattern and can be expected in less mature and even some full-term babies. However, the pattern of breathing, length of breathing pauses, and the age of the baby are both important when deciding if it needs to be further evaluated.
Apnea episodes or "events" that last longer than 20 seconds are considered serious. The baby may also have a:
- Drop in heart rate. This heart rate drop is called bradycardia (also called a "brady").
- Drop in oxygen level (oxygen saturation). This is called desaturation (also called a "desat").
Exams and Tests
All premature babies under 35 weeks gestation are admitted to newborn intensive care units, or special care nurseries, with special monitors because they are at higher risk for apnea. Older babies who are found to have apnea episodes will also be placed on monitors in the hospital. More tests will be done if the baby is not preterm and appears unwell.
- Monitors keep track of breathing rate, heart rate, and oxygen levels.
- Drops in breathing rate, heart rate, or oxygen level can set off the alarms on these monitors.
- Baby monitors marketed for home use are not the same as those used in the hospital.
Alarms may occur for other reasons (such as passing stool or moving around), so the monitor tracings are reviewed regularly by the health care team.
Treatment
How apnea is treated depends on:
- The cause
- How often it occurs
- Severity of episodes
Babies who are otherwise healthy and have occasional minor episodes are simply watched. In these cases, the episodes go away when the babies are gently touched or "stimulated" during periods when breathing stops.
Babies who are well, but who are very premature and/or have many apnea episodes may be given caffeine. This will help make their breathing pattern more regular. Sometimes, the nurse will change a baby's position, use suction to remove fluid or mucus from the mouth or nose, or use a bag and mask to help with breathing.
Breathing can be assisted by:
- Proper positioning
- Slower feeding time
- Oxygen
- Continuous positive airway pressure (CPAP)
- Breathing machine (ventilator) in extreme cases
Some infants who continue to have apnea but are otherwise mature and healthy may be discharged from the hospital on a home apnea monitor, with or without caffeine, until they have outgrown their immature breathing pattern.
Outlook (Prognosis)
Apnea is common in premature babies. Mild apnea does not appear to have long-term effects. However, preventing multiple or severe episodes is better for the baby over the long-term.
Apnea of prematurity most often goes away as the baby approaches their "due date." In some cases, such as in infants who were born very prematurely or have severe lung disease, apnea may persist a few weeks longer.
References
Ahlfeld SK. Respiratory tract disorders. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KW, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 122.
Mitchell LJ, Macfarlane PM, Bavis RW, Martin RJ. Pathophysiology of apnea of prematurity. In: Polin RA, Abman SH, Rowitch DH, Benitz WE, Fox WW, eds. Fetal and Neonatal Physiology. 6th ed. Philadelphia, PA: Elsevier; 2022:chap 156.
Patrinos ME. Neonatal apnea and the foundation of respiratory control. In: Martin RJ, Fanaroff AA, Walsh MC, eds. Fanaroff and Martin's Neonatal-Perinatal Medicine. 11th ed. Philadelphia, PA: Elsevier; 2020:chap 67.
Reviewed By: Mary J. Terrell, MD, IBCLC, Neonatologist, Cape Fear Valley Medical Center, Fayetteville, NC. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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