Minimally invasive surfactant therapy: An update

Preterm infants who have respiratory distress syndrome have for many years been managed with a combination of early intubation and exogenous surfactant therapy. It is now recognized that applying continuous positive airway pressure (CPAP) in an extremely preterm infant is a reasonable alternative to early intubation after birth. Meta-analysis of large controlled trials comparing these two approaches suggests a benefit of CPAP, with a small reduction in the risk of the composite outcome of death or bronchopulmonary dysplasia. In the past decade, there has been an upsurge in the use of CPAP as primary therapy for preterm infants, bringing with it the dilemma of whether and how to give exogenous surfactant. In an effort to circumvent this problem, techniques of minimally invasive surfactant therapy have recently been investigated, aiming to administer surfactant to spontaneously breathing infants, allowing them to remain on CPAP in the critical first days after birth and, hopefully, beyond. These techniques have included administration of exogenous surfactant by brief tracheal catheterization, aerosolization, and laryn-geal mask. Of these, the methods involving brief tracheal catheterization have been most extensively studied, with surfactant administered by using both a flexible feeding tube and a semi-rigid vascular catheter. In recent clinical trials (AMV [Avoidance of Mechanical Ventilation by Surfactant Administration] trial, Take Care study, and NINSAPP [Surfactant Application During Spontaneous Breathing With Continuous Positive Airway Pressure in Premature Infants <27 Weeks] trial), surfactant delivery via a feeding tube was found to reduce the need for subsequent intubation and ventilation and to improve short-term respiratory outcomes. Despite the relatively small numbers of infants in these trials, this technique has found its way into clinical practice in some centers. Further randomized controlled trials of surfactant administration via tracheal catheterization are underway or planned, and they will help clarify the place of this therapeutic approach. Additional studies will be needed to identify the best means of infant selection, refine the instillation technique, resolve the uncertainties regarding sedation, and determine the optimal surfactant dosage.