Objective To evaluate practice variations amongst neonatologists regarding oxygen management in neonates with persistent pulmonary hypertension of newborn (PPHN). Study Design An online survey was administered to neonatologists to assess goal oxygenation targets and oxygen titration practices in PPHN. Response variations were assessed and intergroup comparisons performed. Results Thirty-three percent (492) of neonatologists completed the survey. Twenty-eight percent reported using specific oxygen titration guidelines. Majority of respondents used a combination of oxygen saturation (SpO2) and arterial oxygen tension (PaO2) initially to titrate oxygen. Seventy percent of the respondents used higher goal SpO2 > 95% or 95 to 98% and thirty-eight percent of the respondents used PaO2 > 80 mm Hg. Physicians with extracorporeal membrane oxygenation experience and those with greater than ten years neonatal intensive care unit experience inclined toward use of SpO2 alone for oxygen titration and aimed for lower range of SpO2 and PaO2 targets. Greater proportion of neonatologists who employed specific oxygen titration guidelines used lower SpO2 targets. Conclusion Wide practice variations exist amongst neonatologists regarding optimal SpO2 and PaO2 targets and oxygen titration practices in the management of PPHN.

Background High flow nasal cannula (HFNC) improves ventilation by washing out nasopharyngeal dead space while delivering oxygen. Heliox (Helium-oxygen gas mixture), a low density gas mixture, decreases resistance to airflow, reduces the work of breathing and facilitates distribution of inspired gas. Excessive lung work and potential injury increases the workload on the immature diaphragm predisposing the muscle to fatigue and can lead to inflammatory and oxidative stress, thereby contributing to impaired diaphragmatic function. We tested the hypothesis that HFNC with Heliox will decrease the work of breathing thereby unloading the neonatal diaphragm and potentially reducing diaphragmatic injury. Methods Spontaneously breathing neonatal pigs were randomized to Nitrox (Nitrogen-oxygen gas mixture) or Heliox and studied over 4 hrs following oleic acid injury. Gas exchange, pulmonary mechanics indices and systemic markers of inflammation were measured serially. Diaphragm inflammation biomarkers and histology for muscle injury were assessed at termination. Results Heliox breathing animals demonstrated decreased respiratory load and work of breathing with lower pressure- rate product, lower labored breathing index, and lower levels of diaphragmatic inflammatory markers and muscle injury score as compared to Nitrox. Conclusion These results suggest that HFNC with Heliox is a useful adjunct to attenuate diaphragmatic fatigue in the presence of lung injury by unloading the diaphragm, resulting in a more efficient breathing pattern and decreased diaphragm injury.

High flow nasal Heliox decreased respiratory load, reduced resistive work of breathing indices and attenuated lung inflammatory profile while ventilation was supported at less pressure effort in the presence of acute lung injury.