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Apnea in infants represents a clinically significant condition encompassing a spectrum of etiologies, from physiologic immaturity in preterm infants to underlying pathologic causes in term infants. Despite established diagnostic frameworks and evidence-based management guidelines, clinicians continue to demonstrate variability in recognizing apnea subtypes, stratifying risk, and selecting appropriate evaluation strategies. This activity provides a comprehensive review of infant apnea, including its classification, etiology, pathophysiology, and differentiation from benign periodic breathing. Participants examine current evidence supporting targeted diagnostic workup, methylxanthine therapy, and safe discharge planning. The activity also addresses the 2016 American Academy of Pediatrics transition from the term "apparent life-threatening event" to "brief resolved unexplained event" and the clinical implications of this change. Upon completion, participants demonstrate improved competence in risk stratification, evidence-based management, prevention of complications, and coordinated interprofessional care for infants presenting with apnea. Objectives: Identify the major etiologies of central, obstructive, and mixed apnea in infants, including central nervous system disorders, upper airway abnormalities, and gastroesophageal reflux disease, to inform targeted clinical evaluation. Assess infants with suspected apnea by distinguishing periodic breathing and breath-holding spells from true apnea using gestational age, event characteristics, and targeted physical examination findings. Implement evidence-based diagnostic testing and treatment plans for apnea in infants by selecting appropriate laboratory and imaging studies, initiating gestation-appropriate monitoring, and targeted therapy. Collaborate with neonatologists, nurses, respiratory therapists, and subspecialty consultants to develop coordinated discharge plans that include safe sleep education, medication discontinuation criteria, and family training in basic resuscitation skills. Access free multiple choice questions on this topic.

Apnea in infants refers to episodes of breathing cessation and may result from various physiological and pathophysiological processes. Brief periods of apnea occurring in short cycles of 5 to 10 seconds are not pathologic and are referred to as periodic breathing. Periodic breathing is seen predominantly between the ages of 2 and 4 weeks and resolves by age 6 months.[1][2] Apnea is frequently seen in preterm infants but can occur at any age. Apnea of prematurity is defined as a sudden cessation of breathing lasting at least 20 seconds, or accompanied by bradycardia or oxygen desaturation (cyanosis), in an infant younger than 37 weeks' gestational age. Apnea of infancy is defined as an unexplained episode of cessation of breathing for 20 seconds or longer, or a shorter respiratory pause associated with bradycardia, cyanosis, pallor, or marked hypotonia in full-term infants (older than 37 weeks of gestation). Apnea may be central, obstructive, or mixed: Central apnea results from depression of the central respiratory centers, with cessation of respiratory output and absence of respiratory effort. Obstructive apnea occurs when airway obstruction and inadequate respiratory effort prevent ventilation. Mixed apnea is a period of central apnea with absent respiratory effort, typically followed by continued respiratory effort against a closed or obstructed airway, and is the most common type among preterm infants.

The etiology of apnea in infants is broad and varies with the infant’s age and the underlying pathophysiological mechanism.[3][4][5] Preterm infants, especially those younger than 28 weeks of gestation, are highly prone to apnea due to the immature development of mechanisms of respiratory control and have apnea of prematurity. Feeding can trigger apnea of prematurity. While hypoxemia during feeding is most likely related to immature coordination between sucking, swallowing, and breathing, and potentially also to an immature laryngeal chemoreflex, hypoxemia after feeding may be caused by diaphragmatic fatigue. Gastroesophageal reflux, contrary to common belief, is not usually the culprit.[6] Apnea soon after birth can occur due to birth asphyxia, maternal drug use, infections, metabolic causes, and congenital anomalies. Causes of central apnea include central nervous system infections (meningitis, encephalitis), head trauma (birth asphyxia or abusive trauma), toxin exposure, pertussis, infant botulism, inborn errors of metabolism (mitochondrial disease, Pompe disease, Leigh syndrome, and the mucopolysaccharidoses), metabolic derangements (hypoglycemia, hypocalcemia, and acidosis), and congenital anomalies (congenital central hypoventilation, Down syndrome, and Arnold-Chiari malformation). Obstructive apnea can occur due to obstructive sleep apnea,[7] infections (pneumonia, croup), vocal cord paralysis, and congenital upper airway anomalies (eg, Pierre-Robin sequence). Mixed apnea occurs predominantly among preterm infants but can also be caused by gastroesophageal reflux, pertussis, and bronchiolitis.

The true prevalence and incidence of apnea in infants are unknown. Among preterm infants, the incidence of apnea is inversely related to gestational age. Almost every infant younger than 28 weeks' gestation has an episode; 50% of infants born between 33 and 34 weeks have 1, and the incidence decreases to 20% by 34 weeks' gestation.[8] The incidence of apnea in the full-term infant is 1 per 1000.[9]

The relatively immature respiratory center in infants, particularly preterm infants, makes them vulnerable to apneic episodes in response to internal and external stressors.[10][11] Unlike adults and older children, neonates respond to hypoxia and hypercarbia with a brief increase in respiratory rate followed by respiratory depression and apnea. During feeding, poor coordination of sucking and breathing impairs ventilation, further exacerbated by exaggerated laryngeal chemoreflexes that depress the respiratory center and cause apnea. Infants are susceptible to stressors such as anemia, hypoglycemia, hypothermia, and toxin exposure that can depress the respiratory center. The very pliable thoracic cage causes chest wall collapse, leading to increased work of breathing, chest muscle fatigue, and respiratory failure and apnea. Apnea of infancy in full-term infants typically results from specific underlying pathologic conditions rather than developmental immaturity, distinguishing it fundamentally from apnea of prematurity. The pathophysiology varies by etiology, with the 3 most common causes being gastroesophageal reflux disease (48%), upper airway abnormalities and obstruction (37%), and neurologic diseases (19%). However, many infants have multiple contributing factors.[12]

The initial history should distinguish between a true apneic episode and periodic breathing or a breath-holding spell. Once the episode is classified as apneic, the approach to history and physical examination differs substantially depending on gestational age at birth: apnea of prematurity reflects physiologic immaturity, whereas apnea of infancy requires evaluation for specific pathologic causes. For preterm infants (younger than 37 weeks), apnea of prematurity reflects physiologic immaturity of respiratory control and typically resolves by 40 weeks postgestational age. The history should focus on gestational age, the timing of events relative to feeding and positioning, and associated symptoms (bradycardia, desaturation), while the physical examination should assess maturity and rule out acute illness (infection, metabolic derangements, anemia).[13][14][15] In contrast, full-term infants (≥37 weeks) presenting with apnea of infancy require systematic evaluation for underlying pathology, with the 3 most common etiologies being gastroesophageal reflux disease (48%), upper airway abnormalities and obstruction (37%), and neurological diseases (19%).[12] For term infants, the history should elicit feeding-related symptoms (choking, regurgitation), upper airway symptoms (stridor, noisy breathing, positional changes), and neurological concerns (abnormal movements, altered tone, seizure-like activity), while physical examination systematically evaluates nasal patency, oropharyngeal structure, neurological tone and reflexes, and respiratory patterns in different positions.[12][16][17]

The history and physical examination findings should guide the selection of laboratory and imaging studies. In neonates, complete blood counts, serum glucose, calcium, and electrolyte levels can be considered. If the infant is febrile or hypothermic and a serious infection is suspected, appropriate cultures of blood, urine, and possibly cerebrospinal fluid should be obtained.[18] An electrocardiogram can be performed to rule out cardiac dysrhythmias, especially long QT syndrome.[19] Neuroimaging, electroencephalogram, and specialist consults are not routinely recommended unless specifically indicated by the clinical picture. If the infant meets low-risk criteria for a brief resolved unexplained event, no laboratory studies are indicated.[20][21]

The initial step in managing apnea in infants is to assess whether immediate resuscitation or stabilization is needed. Subsequent management consists of determining the underlying etiology and instituting targeted therapy for the identified cause. For neonates, a period of observation with cardiorespiratory and pulse oximetry monitoring in the neonatal intensive care unit is recommended. For infants with apnea of prematurity, interventions are recommended if apneic spells are frequent, prolonged, require frequent stimulation, or are associated with bradycardia and hypoxia. These infants benefit from nasal continuous positive airway pressure and methylxanthine therapy. Methylxanthines and continuous positive airway pressure are not routinely indicated in term infants. Speech or occupational therapy may be consulted for infants with feeding-related issues. Treatment for infants in the low-risk, brief-resolved unexplained event category consists of parental reassurance and education.[16][22][23]

The differential diagnosis of apnea in infants includes: Aspiration syndrome Anemia of prematurity Botulism Bronchiolitis Bronchopulmonary dysplasia Pediatric sleep apnea Croup Congenital heart disease with pulmonary hypertension; congestive heart failure Inborn errors of metabolism Influenza Laryngomalacia Munchausen syndrome by proxy (factitious disorder imposed on another) Sepsis from serious bacterial or viral infection

Counseling parents on safe sleep and other recommended habits is extremely important. Parental reassurance and addressing of concerns are primary considerations. Educating parents and caretakers about concerning signs and symptoms, when to seek care, and training them in basic resuscitation skills (eg, how to manage choking or perform cardiopulmonary resuscitation) are also important.

Apneic episodes may sometimes be categorized as an apparent life-threatening event. The term apparent life-threatening event describes an acute event that appears frightening to the caregiver and includes some combination of apnea, bradycardia, color change (usually cyanosis or pallor, occasionally plethora), and choking or gagging. In 2016, the American Academy of Pediatrics recommended discontinuing the use of "apparent life-threatening event" as a diagnosis and recommended the alternative term "brief resolved unexplained event."

Apnea in infants has many causes, may present intermittently, and, if left untreated, may have undesirable consequences. Intermittent hypoxia from continuing apnea and periodic breathing may cause hypoxic cerebral injury and potentially worsen neurodevelopmental outcomes.[13] Apnea caused by sepsis or a neurological insult carries a very high mortality rate.[23][24][25] Untreated apnea can lead to failure to thrive, loss of intellect, and cor pulmonale. Therefore, health care professionals, including nurses, must be aware of apnea and its clinical presentation. In general, apnea is more common in low birth weight infants and affects anywhere from 1% to 7.5% of hospitalized infants. Effective coordination requires clearly defined roles. Neonatologists lead diagnostic evaluation, treatment decisions, and discharge planning.[26] Nurses and respiratory therapists provide continuous monitoring, implement tactile stimulation, and manage respiratory support devices.[14] Specialists (neurology, cardiology, gastroenterology) evaluate secondary causes when indicated.[14] Coordinated discharge planning should include clear criteria for medication discontinuation, observation periods, and family education on safe sleep practices.[13]