Fig 2. Mean PaCO₂ values over time of surfactant-depleted rabbits managed with non-invasive ventilation.

Surfactant-depleted adult rabbits were treated with NCPAP only (white diamonds), with NCPAP+SF (black diamonds), with NIPPV only (white squares), with NIPPV+SF (black squares), with SNIPPV only (white circles), or with SNIPPV+SF (black circles). Surfactant-treated animals (black symbols) received a bolus of surfactant before extubation, immediately after the 0 time-point. Values are shown as the mean ± SEM * P vs. NIPPV group < 0.01; ^# P vs. NIPPV+SF group < 0.01; ^§ P vs. all other groups < 0.01.