Article
Resolution of Apnea of Prematurity (AOP) in 24-28 Week Gestational Age (GA) Infants Is No Different from Preterms 31-34 Weeks GA
Pediatric Research
(1999)
Abstract
Apnea of prematurity is a very common neonatal diagnosis occurring in 85% of infants less than 34 weeks GA, increasing in frequency with decreasing GA. The resolution of AOP in 24-28 wk GA infants has been reported to occur beyond 40 wks corrected age (CA) in 14% of patients (Eichenwald, etal, Pediatrics, 1997). However, the frequency of AOP persisting beyond 40 wks CA did not appear to be as high in our population. To determine the CA at which preterm infants 24-28 wks GA vs 31-34 wks GA resolve their AOP we performed a retrospective chart review. The records of all infants cared for in the NICU at University Hospital Stony Brook born at 24-28 wks GA and 31-34 wks GA between January 1995 to December 1997 were reviewed. We compared the incidence of AOP by GA, the frequency of AOP beyond 40 wks CA, and the CA at hospital discharge between these two groups. Resolved AOP for hospitalized patients was defined as a 1 week apnea-free interval off methylxanthines. For infants discharged with AOP, resolved AOP was defined as no witnessed or documented events off methylxanthines. We reviewed the charts of 595 infants were 24-28 wk GA and 415 infants were 31-34 wk GA. The incidence of AOP was 83% in the 24-28 wk group and 25% in the 31-34 wk group (p<0.05). We found no difference in the percent of infants with unresolved AOP at 40 weeks CA. 8% (12/150) in the 24-28 wk group vs 5% (5/104) in the 31-34 wk group. Thirty-five percent of the 17 infants with persistent AOP at 40 weeks CA were also being treated for gastroesophageal reflux. The CA at hospital discharge of those infants who were diagnosed with AOP was significantly different between the two groups, 37.5 ± 0.6 in the 24-28 wk group vs 35.7± 0.4 weeks in the 31-34 wk group (p<0.05). This suggests that the most premature infants gain a functional maturity (feeding ability, thermoregulation, and cardiorespiratory stability) at a later CA than 31-34 wk group. Alternatively, the 24-28 wk GA infants often have a more complicated neonatal course including BPD, ROP, and NEC that may contribute to their later CA at discharge. Preterm infants with a diagnosis of AOP were discharged at an older CA than those who never had AOP. This suggests that infants with AOP are less mature at any given CA than their AOP-free counterparts. We conclude that persistence of AOP beyond 40 weeks CA in infants 24-28 weeks GA is less common than previously reported, occurring in about 8%. This difference from the previous study may be related to differences in clinical practices between institutions. We speculate that premature infants who continue to be symptomatic beyond 40 weeks CA are likely to have a diagnosis other than AOP (for example GER, RSV).
Disciplines
Publication Date
April, 1999
Citation Information
Nwanneka Nwokolo, Susan Katz and Joseph D DeCristofaro. "Resolution of Apnea of Prematurity (AOP) in 24-28 Week Gestational Age (GA) Infants Is No Different from Preterms 31-34 Weeks GA" Pediatric Research Vol. 45 (1999) p. 251 Available at: http://works.bepress.com/susan-katz/5/