Periodic breathing and apnea in preterm infants.
The relationship between periodic breathing and idiopathic apnea of prematurity was investigated. We recorded respiratory impedance, heart rate, pulse oximetry and end-tidal CO2 from 68 untreated infants of less than or equal to 34 wk gestation with a diagnosis of idiopathic apnea of prematurity. Mean birth wt was 1476 g (SD 420) and mean gestational age was 29.9 wk (SD 2.6). Apneas of more than 15 s duration that were associated with hypoxemia or bradycardia were identified by semiautomated analysis of computerized records. A total of 1116 significant apneic spells were identified, only one of which occurred during an epoch of periodic breathing, five others occurred within 2 min of the end of an epoch of periodic breathing. Less than 0.6% of significant apneic spells occur within 2 min of periodic breathing. In all of the 12 infants that were monitored starting in the first 12 h of life, significant apneic spells were identified before 36 h of age and no precipitating factors were identified. Periodic breathing did not occur during the first 48 h of life, a finding that supports the concept that the peripheral chemoreceptor is inactive in the first 48 h of life. Periodic breathing in the premature infant is not a precursor to significant apnea.
Barrington
K J
KJ
University of Alberta, Division of Paediatric Critical Care, Edmonton, Canada.
Finer
N N
NN
D001049:Apnea / Q000209:etiology / Q000503:physiopathology*; D002344:Carotid Body / Q000503:physiopathology; D002628:Chemoreceptor Cells / Q000503:physiopathology; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D010507:Periodicity; D012119:Respiration / Q000502:physiology*