Background
Our understanding of the anatomy, physiology, biochemistry, and molecular biology of neonatal breathing has increased in recent years.
For instance, emerging data are elucidating the genes involved in the embryonic development of central respiratory centers and their neural networks.
The central respiratory generator is essential for fetal breathing movements. It appears early in pregnancy and importantly contributes to pulmonary development.
In the fetus, breathing is intermittent and occurs during the low-voltage electrocortical state (analogous to rapid eye movement [REM] sleep) and becomes continuous immediately after birth. The regulatory neurologic mechanisms that cause the transition from intermittent fetal breathing to continuous neonatal breathing are incompletely appreciated.
After birth, apnea of prematurity (AOP) is a major concern for caregivers in intensive care nurseries. The magnitude of this problem resulted in the National Institutes of Child Health and Human Development (NICHD) convening a workshop on apnea of prematurity. Summary Proceedings from the Apnea-of-Prematurity Group have been published.
The NICHD review group emphasized the following conclusions:
No consensus has been reached regarding the definition, diagnosis, or treatment of apnea of prematurity.
Systematic research has not been conducted to investigate the value of different interventions for apnea of prematurity.
Available technology is not routinely used to document real-time events associated with apnea.
The time required to demonstrate an improvement in apnea of prematurity with a specific treatment has not been established.
The observational period needed after therapy for apnea of prematurity is unknown, and an appropriate duration of surveillance off therapy is needed to reasonably prevent acute life-threatening events.
Important confounding conditions that influence the occurrence of apnea of prematurity are poorly recognized and/or integrated into care.
The relationship between gastroesophageal reflux (GER) and apnea of prematurity requires additional investigation because current knowledge suggests an infrequent association.
Improved characterization of the effects of apnea of prematurity on neurodevelopment during infancy and childhood is needed.
Other confounders associated with brain injury in preterm infants are difficult to separate from apnea of prematurity as meaningful causes of abnormal child development.
The NICHD review group also made recommendations about what issues associated with apnea of prematurity that need urgent attention, what research methods might be best for future studies, what outcomes are essential to our understanding of apnea of prematurity, and what ethical principles should govern future investigations of apnea of prematurity.
Given this discussion from the NICHD review group, the present article provides state-of-the-art information regarding what is and what is not known about apnea of prematurity.