General procedures
DECUBITUS
The TIE index incorporates the time domain into the assessment of muscle inspiratory function. It is calculated as the ratio of PImax registered after the first 30 s of observation by the time required to reach it, while keeping the airways occluded with a unidirectional valve for up to 60 s. The TIE MeterBefore testing, all participants were ventilated under pressure-support mode (≤10 cmHFor the spontaneous breathing trial, subjects were positioned in dorsal decubitus with the head elevated at 45° with a low-flow oxygen support (∼40% FIOThe criteria to proceed with extubation was either a TIE index ≥1 cm H