Page 52 - Physiological based CPAP for preterm infants at birth Tessa Martherus

Chapter 2
1.0. However, collectively the results of these trials are inconsistent and meta-analyses (28-30) have concluded that there is insufficient data to recommend a strategy for very preterm infants.
In this retrospective matched-pairs study, we explored two respiratory support approaches using either higher oxygen or titrated CPAP. At the Leiden University Medical Center (LUMC), CPAP pressures of 5-8 cmH2O and/or PPV are given while FiO2 levels are titrated between 0.3 and 1.0. At the University Hospital of Cologne, respiratory support commences with a CPAP of 12 cmH2O and CPAP pressures are step-wise increased up to a maximum of 32 cmH2O. The FiO2 is usually kept between 0.3 and 0.4. The large differences in respiratory support strategies prompted us to compare the immediate effect of these two different approaches on the physiological and short-term clinical outcomes.
Materials and methods
We performed a retrospective matched-pairs study and included infants born between 24 0/7 and 27 6/7 weeks of gestation. Infants born between the introduction of the New Life Box respiratory function monitor (Applied Biosignals, Weener, Germany) and August 2017 were included. The monitor was introduced at the University Hospital of Cologne in August 2014 and at the LUMC in March 2014. Infants with congenital abnormalities were excluded, as well as infants who’s recording could not be identified or infants with incomplete files. Infants born at the University Hospital of Cologne were matched 1:1 with infants born at the LUMC. Matching criteria were gestational age (+/- 4 days) and birth weight (+/- 25% grams). The database was scanned in chronological order and in case of multiple potential matches, the first potential match was included. Infants could not be matched in a 1:2 ratio due to an unequal distribution of gestation and birth weight.
Study Protocols
At the LUMC (low-pressure group), 5 cmH2O CPAP is given initially and can be increased to 8 cmH2O. If the infant is apneic or bradycardic, sustained inflations (20-25 cmH2O, 15 s) and PPV (PIP 25 cmH2O, 40-60/min) are given. The fraction of inspired oxygen (FiO2) is initially set at 0.3 and can be adjusted step-wise up to 1.0 based on the 25th percentile of the Dawson criteria. Respiratory support was provided by the NeopuffTM T- Piece resuscitator (Neopuff Infant Resuscitator, Fisher & Paykel Healthcare Ltd., Auckland, New Zealand) via facemask (Neonatal Resuscitation Mask, Fisher & Paykel Healthcare Ltd, Auckland, New Zealand).
In the University Hospital of Cologne (high-pressure group) infants are initially supported with 12 cmH2O CPAP, delivered by the Benveniste ValveTM (Dameca, Löwenstein Group, Rødovre, Denmark) via facemask (Disposable Face Mask Neonate, Ambu A/S, Ballerup, Denmark). If infants are apneic or bradycardic, the flow is increased by 2L/min subsequently increasing the pressure to a maximum of 32 cmH2O. Sustained inflations and positive pressure ventilation are not included in the local protocol. The FiO2 is initiated at 0.3 and can be increased to 0.4.
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