Airway lavage with exogenous surfactant in an animal model of meconium aspiration syndrome

Background: Meconium aspiration syndrome (MAS) is a major cause of respiratory morbidity and mortality in term infants, and occasionally causes serious respiratory disturbance. Viscous meconium debris in the trachea interferes with ventilation, and chest physiotherapy (CPT) is effective for removing secretions from the trachea. The effects of conventional exogenous diluted surfactant lavage combined with CPT were evaluated in a MAS animal model in a randomized controlled study. Methods: Twenty-three MAS model adult Japanese rabbits were randomized into three groups and artificially ventilated for 3 h with the following treatments: group 1, suction only (n = 7); group 2, surfactant lavage (n = 7); group 3, surfactant lavage with CPT (n = 7). Surfactant lavage was performed by infusing 2 mL/kg of diluted Surfactant TA (Surfacten; 6 mg/mL) into the trachea over approximately5 s, then performing gentle manual bagging six times, and aspirating the tracheal contents using a suction catheter. This procedure was performed four times in four different positions (total, 8 mL/kg). In group 3, CPT (squeezing) was performed during expiration of manual bagging in surfactant lavage. Results: In group 3, PaO2 improved significantly (P < 0.05) at all time points compared with those in the other groups. Oxygenation index (OI) in group 3 improved significantly (P < 0.05) at all time points except after 0.5 h compared with that in group 1, and at 2, 2.5, and 3 h compared with that in group 2. Conclusions: A combination of exogenous surfactant lavage and CPT (squeezing) improves respiratory disturbance in MAS.