Natural Versus Synthetic Surfactant Therapy in Respiratory Distress Syndrome of Prematurity

Pulmonary Surfactant in Adult ARDS: Current Perspectives and Future Directions

Acute respiratory distress syndrome (ARDS) is a major cause of hypoxemic respiratory failure in adults, leading to the requirement for mechanical ventilation and poorer outcomes. Dysregulated surfactant metabolism and function are characteristic of ARDS. A combination of alveolar epithelial damage leading to altered surfactant synthesis, secretion, and breakdown with increased functional inhibition from overt alveolar inflammation contributes to the clinical features of poor alveolar compliance and alveolar collapse. Quantitative and qualitative alterations in the bronchoalveolar lavage and tracheal aspirate surfactant composition contribute to ARDS pathogenesis. Compared to neonatal respiratory distress syndrome (nRDS), replacement studies of exogenous surfactants in adult ARDS suggest no survival benefit. However, these studies are limited by disease heterogeneity, variations in surfactant preparations, doses, and delivery methods. More importantly, the lack of mechanistic understanding of the exact reasons for dysregulated surfactant remains a significant issue. Moreover, studies suggest an extremely short half-life of replaced surfactant, implying increased catabolism. Refining surfactant preparations and delivery methods with additional co-interventions to counteract surfactant inhibition and degradation has the potential to enhance the biophysical characteristics of surfactant in vivo.

Surfactant Replacement Therapy: What’s the New Future?

Surfactant replacement therapy (SRT) can be lifesaving for preterm babies with respiratory distress because of surfactant deficiency. Attempts have been made over the last two decades to make surfactant administration as smooth and as nontraumatic as possible. Lesser invasive techniques, such as less invasive surfactant administration, minimally invasive surfactant therapy, intrapartum pharyngeal surfactant therapy, and the laryngeal mask airway, are preferred over invasive techniques like intubate surfactant extubation to reduce trauma and peridosing adverse effects. However, at present, aerosolized surfactant (AS) via nebulization remains the only truly noninvasive method of SRT. Many animal and human studies have shown promising results with the use of AS with similar clinical effects to an instilled surfactant with greater safety potential. But still AS has not been adapted to routine neonatal care. There is still scope for studies to further strengthen the role of AS. Also, SRT is a constantly changing field with new innovations revolutionizing and replacing old techniques.