Large volume instillation of surfactant during extracorporeal life support improves lung function in lung lavaged rabbits.

The sometimes limited effect of surfactant therapy in neonates might be explained in part by an non homogeneous distribution of the surfactant after endotracheal instillation. This distribution can be improved significantly by increasing the fluid volume. The aim of this study was to evaluate the effect of two methods for gas exchange during a large volume instillation of surfactant on the outcome of this treatment in lung lavaged rabbits. In the control group (n = 6) gas exchange was maintained with continuous positive pressure ventilation (CV), whereas in the other group gas exchange was established with extracorporeal life support (ECLS) (n = 6) and intermittent sighs. Five hours after surfactant administration, an identical weaning procedure was started in both groups. The authors found significantly higher PaO2 values in the ECLS group than in the control group in the normocarbia state. All animals in the ECLS group could be weaned to room air maintaining normal blood gases, whereas all the animals in the control group died in the course of weaning. The ventilator efficiency index was significantly higher during the weaning period in the ECLS group, indicating better lung function, than in the control group. The authors conclude that a large volume instillation of surfactant is feasible by applying ECLS and intermittent sighs. Additional studies are needed to elucidate if this combined treatment will be an improvement over current surfactant therapy.