Extubation Failures

The hypothesis is that the Spontaneous Breathing Test (SBT) without pressure support (PS) is not inferior to the SBT with pressure support in relation to the following outcomes: a) extubation failure; b) time on MV. The main objective of this study is to determine whether SBT without PS is non-inferior to SBT with PS in relation to the primary outcome: a) extubation failure; and secondary outcomes: b) length of stay in the PICU and c) days free of MV. Pacients will be randomized to 2 arms: 1. SBT with PS 2. SBT without PS (with PEEP only)