Treatment with bovine surfactant in severe acute respiratory distress syndrome in children: A randomized multicenter study

Objective: To determine whether bovine surfactant given in cases of severe pediatric acute respiratory distress syndrome (ARDS) improves oxygenation. Design: Single-center study with 19 patients, followed by a multicenter randomized comparison of surfactant with a standardized treatment algorithm. Primary endpoint PaO₂/FIO₂ at 48 h, secondary endpoints: PaO₂/FIO₂ at 2, 4, 12, and 24 h, survival, survival without rescue, days on ventilator, subgroups analyzed by analysis of variance to identify patients who might benefit from surfactant. Setting: Multicenter study in 19 reference centers for ARDS. Patients: Children after the 44th postconceptional week and under 14 years old, admitted for at least 4 h, ventilated for 12-120 h, and without heart failure or chronic lung disease. In the multicenter study 35 patients were recruited; 20 were randomized to the surfactant group and 15 to the nonsurfactant group. Decreasing recruitment of patients led to a preliminary end of this study. Interventions: Administration of 100 mg/kg bovine surfactant intratracheally under continuous ventilation and PEEP, as soon as the PaO₂/FIO₂ ratio dropped to less than 100 for 2 h (in the pilot study increments of 50 mg/kg as long as the PaO₂/FIO₂ did not increase by 20%). A second equivalent dose within 48 h was permitted. Results: In the pilot study the PaO₂/FIO₂ increased by a mean of 100 at 48 h (n=19). A higher PaO₂/FIO₂ ratio was observed in the surfactant group 2 h after the first dose (58 from baseline vs. 9), at 48 h there was a trend towards a higher ratio (38 from baseline vs. 22). The rate of rescue therapy was significantly lower in the surfactant group. Outcome criteria were not affected by a second surfactant dose (n=11). A significant difference in PaO₂/FIO₂ in favor of surfactant at 48 h was found in the subgroup with an initial PaO₂/FIO₂ ratio higher than 65 and in patients without pneumonia. Conclusions: Surfactant therapy in severe ARDS improves oxygenation immediately after administration. This improvement is sustained only in the subgroup of patients without pneumonia and that with an initial PaO₂/FIO₂ ratio higher than 65.