Apnea in the Preterm Infant

Key Features

Essentials of Diagnosis

• Respiratory pause of sufficient duration to result in cyanosis or bradycardia

• Most common in infants born before 34 weeks' gestation; onset before 2 weeks of age

• Methylxanthines (eg, caffeine) provide effective treatment

General Considerations

• Defined as a respiratory pause lasting more than 20 seconds—or any pause accompanied by cyanosis and bradycardia

• Causes

  • Temperature instability—both cold and heat stress

  • Response to passage of a feeding tube

  • Gastroesophageal reflux

  • Hypoxemia

    • Pulmonary parenchymal disease

    • Patent ductus arteriosus

    • Anemia

  • Infection

  • Sepsis (viral or bacterial)

  • Necrotizing enterocolitis

  • Metabolic causes

    • Hypoglycemia

  • Intracranial hemorrhage

  • Posthemorrhagic hydrocephalus

  • Seizures

  • Drugs (eg, morphine)

  • Apnea of prematurity

Clinical Findings

• Onset is typically during the first 2 weeks of life

• Frequency of episodes gradually increases with time

• Pathologic apnea should be suspected if episodes are sudden in onset, unusually frequent, or very severe

• Apnea at birth or on the first day of life is unusual but can occur in the nonventilated preterm infant

• In the full-term or late preterm infant, presentation at birth suggests neuromuscular abnormalities of an acute (asphyxia, birth trauma, or infection) or chronic (eg, congenital hypotonia or structural CNS lesion) nature

Diagnosis

• All infants—regardless of the severity and frequency of apnea—require a minimum screening evaluation, including

  • A general assessment of well-being (eg, tolerance of feedings, stable temperature, normal physical examination)

  • A check of the association of spells with feeding

  • Measurement of PaO₂ or SaO₂

  • Blood glucose

  • Hematocrit

  • Review of the drug history

• Infants with severe apnea of sudden onset require more extensive evaluation for primary causes, especially infection

Treatment

• Any underlying cause should be treated

• If the apnea is due simply to prematurity, symptomatic treatment is dictated by the frequency and severity of apneic spells

• Spells frequent enough to interfere with other aspects of care (eg, feeding), or severe enough to cause cyanosis or bradycardia necessitating significant intervention or bag and mask ventilation require treatment

• Caffeine citrate (20 mg/kg as loading dose and then 5–10 mg/kg/d) is the drug of choice

  • Side effects are generally mild and include tachycardia and occasional feeding intolerance

  • Target drug level is usually 10–20 μg/mL

• Nasal continuous positive airway pressure (CPAP) is effective in some infants

• Intubation and ventilation can eliminate apneic spells but carry the risks associated with endotracheal intubation.

• Although many preterm infants are treated medically for possible reflux-associated apnea, there is little evidence to support this intervention; if suspected, a trial of continuous drip gastric or transpyloric feedings can be helpful as a diagnostic and therapeutic intervention

Outcome

Prognosis

• In most premature infants, apneic and bradycardiac spells cease by 34–36 weeks

• Apneic and bradycardiac episodes in the nursery are not predictors of later SIDS, although the ...