This document discusses rational surfactant therapy. It begins by establishing that surfactant replacement therapy works based on multiple randomized controlled trials showing reductions in mortality, duration of ventilation and hospital stay. It describes the types of surfactants available and recommends natural surfactants. The document discusses the timing of surfactant replacement, benefits of multiple doses, and synergistic effects with antenatal steroids. Ventilatory management after surfactant including INSURE technique is covered, along with risks of the therapy.