699 - Higher versus lower PEEP during non-invasive ventilation to stabilize preterm infants within their SpO2 target: a prospective real-life randomized cross-over trial

Publication Number: 4683.699

Stephanie Ströbele, University Medical Center Ulm, Ulm, Baden-Wurttemberg, Germany; Tibor Nikolas. Jung, TH Mittelhessen University of Applied Science, Giessen, Hessen, Germany; Dominik Kraft, TH Mittelhessen - University of Applied Sciences, Gießen, Hessen, Germany; Jens Dreyhaupt, Institute of Epidemiology and Medical Biometry, Ulm, Baden-Wurttemberg, Germany; Keywan Sohrabi, Technical University of Central Hesse, University of Applied Sciences, Giessen, Hessen, Germany; Harald Ehrhardt, University Medical Center Ulm, 89075, Baden-Wurttemberg, Germany

Background: Positive endexpiratory pressure (PEEP) stabilizes functional residual capacity and gas exchange during non-invasive mechanical ventilation (NIV) in extremely preterm (EPT) infants. Its use is first-line recommended respiratory support in guidelines around the world to avoid the harms of mechanical ventilation. Whereas there are no significant differences in terms of intubation between a higher and a lower PEEP level for the primary stabilization after delivery, there is a significant lower reintubation rate after extubation using a higher PEEP level. The most effective level of PEEP to stabilize EPT infants within their oxygen saturation (SpO2) target and to avoid the adverse effects of frequent fluctuations outside the target is however unknown.

Objective: To study the efficacy of a +3cmH2O set higher PEEP during NIV compared to the actually applied PEEP during routine care to keep EPT infants within a prespecified SpO2 target.

Design/Methods: This is a prospective single-center real-life randomized cross-over trial, carried out at a level 3 neonatal intensive care unit. EPT infant were assigned in random sequence to their actual (range 4-6 cmH2O) and higher (range 7-9 cmH2O) PEEP level for 24 hours. The primary outcome was the time spent within the SpO2 target (88-95%). Secondary outcomes included frequency and duration of hypoxemic and hyperoxemic episodes, impact on cerebral tissue oxygenation, gas exchange and vital signs.

Results: 24 EPT infants (14/24 male) with a median gestational age of 25+2 weeks at birth and a postnatal age of 34 days were enrolled. The mean time spent within the SpO2 target was significantly increased during the higher compared to the standard PEEP (75.1% vs 70,7%, p=0.03) with an achieved mean airway pressure gradient of +2.87cmH2O (p < 0.001). The higher PEEP showed a trend towards less time spent in hyperoxemia (SpO2 >95%) while the time in hypoxemia (SpO2 < 88%) was similar. A higher PEEP further reduced the spontaneous respiratory rate while no differences were observed in the applied FiO2, transcutaneous pCO2, and heart rate. No adverse events including abdominal distension or feeding intolerance were reported during the higher PEEP intervention.

Conclusion(s): Higher PEEP levels may be superior to stabilize respiratory unstable preterm infants on NIV. The 4.6% increase within the target during the higher PEEP is clinically relevant and deserves further evaluation whether this finding translates into improved prematurity-related outcomes.