Page 133 - Physiological based CPAP for preterm infants at birth Tessa Martherus

Feasibility and effect of physiological based CPAP in preterm infants at birth
increasing CPAP levels after iPPV may induce apnea in some infants. Preferably, CPAP is guided by lung aeration, this cannot be measured during the stabilization of preterm infants yet.
Although only eight infants were included in the PB-CPAP group, we did not observed signs of harm immediately at birth, which is in line with preclinical studies (25, 26). 15 cmH2O CPAP does not seem to cause adverse events at birth, presumably due to the stage of lung aeration (liquid-filled lungs at birth vs aerated lungs hours after birth) and the involvement of the larynx during non-invasive support. A recent sheep study (26) demonstrated that the larynx is involved in pressure transmission to the lungs during spontaneous breathing and can protect the lungs from overexpansion. We also suggest that PB-CPAP does not increase the risk of adverse events compared to current DR respiratory support approaches, as MAPs of ~15 cmH2O are a common occurrence when mask ventilation includes intermittent positive pressure ventilation (35).
The main limitation of this study is the number of included infants, which prevents us from
making appropriate conclusions. While this was caused by various problems that occurred
during the trial, a particular problem was low consent rate as 37 parents declined and
33 parents (31 randomized, 2 parents gave consent but there was insufficient time to perform
the randomization procedure). Potentially, this selection might lead to bias but we have not indication of difference between the patient cohorts (consent vs no consent). We found that
it was difficult for parents to comprehend the complexity of the procedure as CPAP was an
abstract concept for them. 5
Conclusion
This study demonstrated that PB-CPAP may be beneficial but that our current approach is too complex. We were also unable to demonstrate if PB-CPAP improves oxygen saturation. While the increase in oxygenation and lung aeration may not be co-dependent, the difference in gestational age, high FiO2 levels and lack of power could also diminished the effect of CPAP on oxygen saturation. Nevertheless, PB-CPAP did improve lung aeration as reflected by an increased heart rate and shortened duration of iPPV. Short-term neonatal outcomes were similar between groups, however due to the low number of included infants it is not possible to make appropriate conclusions from our study. Future studies may continue investigating PB-CPAP using a simplified version of the current approach.
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