Response to tube breathing in preterm infants with apnea.
In order to analyze the effects of maturity and apnea frequency on the respiratory control of preterm infants, we studied their responses to tube breathing using tubes equivalent to two anatomical dead spaces. Ventilation during tube breathing was expressed as a percentage above baseline and compared to an "expected" value calculated from the volume of the added tube. Twenty-seven preterm infants (median birthweight, 1.14 kg.; and gestational age, 29 weeks) were studied on 86 occasions. The percentage of "expected" ventilation increased with post-conceptional age (r = 0.48, slope = 3.12, P less than 0.0005), from a mean of 73% at 26 weeks up to 104% at 36 weeks. Using multiple regression analysis, neither postnatal age nor apnea frequency had any effect once allowance had been made for post-conceptional age. Although the respiratory adaptation of the most immature infants was poor, this study suggests that infants with apnea show no gross deficit in respiratory control, compared to those without apnea.
Upton
C J
CJ
Department of Neonatal Medicine, City Hospital, Nottingham, United Kingdom.
Milner
A D
AD
Stokes
G M
GM
D001049:Apnea / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D008397:Masks; D012119:Respiration / Q000502:physiology*; D012126:Respiratory Dead Space / Q000502:physiology; D012129:Respiratory Function Tests / Q000295:instrumentation / Q000379:methods; D012720:Severity of Illness Index; D013997:Time Factors