Apnea, transient episodes of bradycardia, and periodic breathing in preterm infants

Apnea Frequently Persists Beyond Term Gestation in Infants Delivered at 24 to 28 Weeks

“…The etiology and physiologic significance of these self-resolved bradycardia events remain unclear. [13][14][15] Episodes of bradycardia in apnea of prematurity are most often associated with apneas of longer duration and may be precipitated by respiratory efforts against an obstructed airway. 16 -18 It has been hypothesized that bradycardia occurring during these longer apneic events may be a reflex response to the consequent hypoxemia and lack of lung inflation.…”

“…16,19 Transient self-resolved episodes of bradycardia without associated central or obstructive apnea also may occur in convalescent premature infants before and after discharge and in healthy term infants up to 6 months of age. 14,15 Thus, these events may be a normal reflex response that should not prompt additional evaluation or monitoring.…”

Variation in Diagnosis of Apnea in Moderately Preterm Infants Predicts Length of Stay

“…Indeed, the California and Massachusetts NICUs policies for low-heart rate alarm limits differed, with the California units setting a low limit of 80 beats per minute compared with 100 beats per minute for Massachusetts sites. No consensus exists about the clinically significant lower limit for bradycardia or the significance of bradycardia without associated apnea in otherwise healthy preterm infants, 1,18,19 allowing for subjective interpretation between sites and clinicians.…”

Levels of Neonatal Care

“…Compared with those born at term, infants born at 34 to 37 weeks' gestation are at increased risk of complications because of their physiologic immaturity. Biological variability exists in the time of attainment of independent thermoregulation 30 ; resolution of apnea, bradycardia, and/or hypoxemic episodes [31][32][33] ; and oral feedings. 34 Near-term infants (35-37 weeks' gestation) are at increased risk of hyperbilirubinemia and kernicterus.…”