Surfactant replacement and open lung concept – Comparison of two treatment strategies in an experimental model of neonatal ARDS

BACKGROUND: Several concepts of treatment in neonatal ARDS have been proposed in the last years. The present study compared the effects of open lung concept positive pressure ventilation (PPV(OLC)) with a conventional ventilation strategy combined with administration of two different surfactant preparations on lung function and surfactant homoeostasis. METHODS: After repeated whole-lung saline lavage, 16 newborn piglets were assigned to either PPV(OLC )(n = 5) or surfactant treatment under conventional PPV using a natural bovine (n = 5) or a monomeric protein B based surfactant (n = 6). RESULTS: Comprehensive monitoring showed each treatment strategy to improve gas exchange and lung function, although the effect on Pa(O2 )and pulmonary compliance declined over the study period in the surfactant groups. The overall improvement of the ventilation efficiency index (VEI) was significantly greater in the PPV(OLC )group. Phospholipid and protein analyses of the bronchoalveolar lavage fluid showed significant alterations to surfactant homoeostasis in the PPV(OLC )group, whereas IL-10 and SP-C mRNA expression was tendentially increased in the surfactant groups. CONCLUSION: The different treatment strategies applied could be shown to improve gas exchange and lung function in neonatal ARDS. To which extent differences in maintenance of lung function and surfactant homeostasis may lead to long-term consequences needs to be studied further.