Poster Presentation & Flash Talk 46th Annual Meeting of the Fetal and Neonatal Physiological Society 2019

The effect of initial high versus low FiO2 on breathing effort in preterm infants at birth: A randomized controlled trial (#102)

Janneke Dekker 1 , Tessa Martherus 1 , Martin Giera 2 , Erin V McGillick 3 4 , Jeroen GJ Hutten 5 , Ruud W van Leuteren 5 , Anton H van Kaam 5 , Stuart B Hooper 3 4 , Arjan B te Pas 1
  1. Neonatology, Leiden University Medical Center, Leiden, The Netherlands
  2. Center Proteomics Metabolomics, Leiden University Medical Center, Leiden, The Netherlands
  3. Hudson Institute of Medical Research, Clayton, VIC, Australia
  4. Obstetrics and Gynaecology, Monash University, Melbourne, VIC, Australia
  5. Department of Neonatology, Emma Children’s Hospital, Amsterdam, The Netherlands

Background        Infants are currently stabilized with initial low FiO2 (0.21-0.3) which increases the risk of hypoxia and suppression of breathing in the first minutes after birth. We hypothesized that initiating stabilization at birth with a high FiO2 (1.0), followed by titration, would improve breathing effort when compared to an initial low FiO2.

Methods             In a bi-centre randomized controlled trial, infants < 30 weeks gestation were stabilized at birth with an initial FiO2 of 0.3 or 1.0, followed by oxygen titration guided by the reference ranges described by Dawson et al.(2010). Primary outcome was minute volume of spontaneous breathing. We also assessed tidal volumes, mean inspiratory flow rate (MIFR) and respiratory rate with a respiratory function monitor in the first 5 minutes after birth. Pulse oximetry was used to measure heart rate and SpO2 values in the first 10 minutes. Hypoxia was defined as SpO2 <25th percentile and hyperoxia as SpO2 >95%.

Results                 52 infants were randomized and recordings were obtained in 44 infants (100% O2-group: n=20, 30% O2-group: n=24). Minute volumes were significantly higher in the 100% O2-group (146.34 ± 112.68 mL/kg/min) compared to the 30% O2-group (74.43 ± 52.19 mL/kg/min), p=0.014. Tidal volumes and MIFR were significantly higher in the 100% O2-group, while the duration of mask ventilation given was significantly shorter (Table 1). Oxygenation was significantly higher in infants in the 100% O2-group (85 (64 – 93)%) compared to the 30% O2-group (58 (46 – 67)%)(p<0.001). The duration of hypoxia was significantly shorter in the 100% O2-group, while the duration of hyperoxia was not different between groups (Table 1). 

Conclusion          Initiating stabilization of preterm infants at birth with 100% O2 led to higher breathing effort, improved oxygenation, and a shorter duration of mask ventilation as compared to 30% O2, without increasing the risk for hyperoxia.5d15ac6ab639b-Table+1+Results+of+breathing+effort+and+oxygenation.jpg