Spontaneous Breathing Trial With T-piece or Inspiratory Pressure Augmentation (SBT-TIP)

A Cluster-Randomized Crossover Trial to Compare Spontaneous Breathing Trial With T-piece or Inspiratory Pressure Augmentation

Weaning is an important process to gradually separate mechanically ventilated patients from ventilators. A good weaning strategy aims to early identify mechanically ventilated patients who are ready for extubation but not to prematurely extubate them. Spontaneous breathing trial (SBT) is a test to assess the patient's ability to breathe spontaneously when extubated. Several methods have been used to conduct an SBT, including T-piece breathing, low-level pressure support ventilation (PSV) of 5-7 cm H2O, continuous positive airway pressure and automatic tube compensation (ATC). The investigators hypothesized that an SBT with inspiratory pressure augmentation increases initial SBT success, reduces the length of invasive mechanical ventilation (iMV) support and does not increase reintubation risk as compared with T-piece, which result in a higher proportion of patients successfully liberated from iMV in the inspiratory pressure augmentation group. However, inspiratory pressure augmentation significantly reduces work of breathing on an SBT as compared with T-piece. Patients extubated following an SBT with inspiratory pressure augmentation may experience increased respiratory effort after extubation and this may increase the use of noninvasive ventilation after extubation. An SBT with inspiratory pressure augmentation increases iMV free days but not MV free days as compared with T-piece. Longer iMV free days may be associated with a lower mortality due to fewer iMV related complication. This study is a pragmatic, cluster-randomized, multiple crossover, multicenter trial to compare SBTs with T-piece versus inspiratory pressure augmentation in weaning outcomes. Mechanically ventilated patients who meet the criteria for readiness to SBT will be included. The patients will use either T-piece or inspiratory pressure augmentation as SBT for weaning according to an ICU-based cluster randomization and crossover sequence.

Cluster-randomization crossover sequence 1: T-piece during odd-numbered months and inspiratory pressure augmentation during even-numbered months.

Cluster-randomization crossover sequence 2: T-piece during even-numbered months and inspiratory pressure augmentation during odd-numbered months.

SBTs with T-piece breathing for one hour during odd-numbered months and SBTs with inspiratory pressure augmentation for one hour during even-numbered months.

SBTs with inspiratory pressure augmentation for one hour during odd-numbered months and SBTs with T-piece breathing for one hour during even-numbered months.

The primary study endpoint is to compare the effect of SBT with T-piece versus inspiratory pressure augmentation on the proportion of patients with successful liberation from invasive mechanical ventilation in the ICU among patients who have started an SBT. Successful liberation is defined as sustaining iMV free for at least five days after extubation.

Time to successful liberation from invasive and noninvasive mechanical ventilation using competing-risks analysis.

Adjusted risk ratio of successful liberation from invasive mechanical ventilation for T-piece versus inspiratory pressure augmentation group.

Inclusion Criteria: Admitted to the adult intensive care unit (ICU) Receiving invasive mechanical ventilation via an endotracheal tube Ready to start an SBT* *The criteria of readiness to an SBT include FiO2 ≤ 0.4, PEEP ≤ 8 cmH2O, minute ventilation ≤ 0.15 L/min/predicted body weight, inspiratory pressure or driving pressure ≤ 14 cm H2O, stable cardiovascular status and no worsening of non-pulmonary organ function. Exclusion Criteria: Age < 20 years Receiving mechanical ventilation via tracheostomy Mechanical ventilation < 12 hours Invasive ventilation started before the index hospitalization On do-not-intubate order