P168 Pre and postnatal factors associated with periodic breathing in preterm infants

INTRODUCTION: Immature cardio-respiratory control in preterm infants often manifests as periodic breathing (PB). A number of pre- and postnatal demographic and clinical factors, such as exposure to maternal smoking, respiratory support and medications may affect respiratory control. We aimed to identify specific factors affecting the frequency of PB in preterm infants before hospital discharge. METHODS: 32 healthy preterm infants (14M, 18F) born between 28–32 weeks of gestational age were studied for 2–3 hours with daytime polysomnography at 31–36 weeks (when they had been off respiratory support for ≥ 3 days). % sleep time spent in PB was calculated. Variables are reported as median (IQR) and were compared with Mann-Whitney U and Chi square tests, between infants who spent greater or less than the median time in PB. RESULTS: 29 infants (91%) exhibited at least one episode of PB. Median sleep time in PB was 9.6% (IQR 0.6, 15.6%). Infants with time in PB above the median spent fewer days on respiratory support (4.0 days (1.0, 7.5) vs 9.0 (6.5, 21.5) days, p=0.035), and were younger (post-menstrual age 33.8 (IQR 32.1, 34.5) vs 35.1 (IQR 32.4, 35.6) weeks, p= 0.039). CONCLUSIONS: Of the large number of maternal and infant demographic and clinical variables examined, we found few associations with the time preterm infants spent in PB. Greater % time spent in PB was associated with earlier discontinuation of respiratory support, however larger studies are required to confirm these findings and to investigate if there are any long-term consequences.