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, 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 (preemies). It consists of short episodes (about 3 seconds) of either shallow breathing or stopped breathing (apnea). These episodes are followed by periods of regular breathing lasting 10 to 18 seconds.

Irregular breathing may be expected in less mature babies. But the pattern of breathing and the age of the baby are both important when deciding how sick the baby is.

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.

Martin RJ. Pathophysiology of apnea of prematurity. In: Polin RA, Abman SH, Rowitch DH, Benitz WE, Fox WW, eds. Fetal and Neonatal Physiology. 5th ed. Philadelphia, PA: Elsevier; 2017:chap 157.

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.

Review Date: 
1/15/2021
Reviewed By: 
Kimberly G. Lee, MD, MSc, IBCLC, Clinical Professor of Pediatrics, Division of Neonatology, Medical University of South Carolina, Charleston, SC. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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