Oral presentations

Introduction:In mechanically ventilated patients, extubation is decided after passing a spontaneous breathing trial (SBT).Supplementary motor area, which can be non-invasively assessed by measuring amplitude of pre-inspiratory potentials (PIPs), is recruited in case of increased respiratory effort.Weaning failure is accompanied by increased respiratory effort.We hypothesized that early increased PIP amplitude from the start of SBT may predict SBT failure.Methods: We performed a single-center physiological prospective study in mechanically ventilated patients meeting weaning criteria.PIP amplitude was measured using electroencephalography under mechanical ventilation and then during the first 15-min of the SBT performed using a T-piece.We compared PIP amplitude between patients who passed a 1-hour SBT and those who failed.Results: Among the 62 patients included, 17 (27%) failed the SBT.Whereas patients who failed the SBT had a lower median amplitude of PIPs under mechanical ventilation than those who passed the SBT (0.6 V [IQR, 0-1.3] vs. 1.9 [1.2-2.9],p < 0.0001), they had a higher amplitude of PIPs at the beginning of the SBT (2.1 V [IQR, 1.7-2.9]vs. 1.2 [0.5-2.0],p < 0.005).The change in PIP amplitude between mechanical ventilation and SBT significantly increased in case of SBT failure whereas it decreased in case of SBT success (+1.7 V [1.2-2.1] vs. -0.5 [-1.8-0.1],p < 0.0001).An increase of PIP above 0.43 V was associated with SBT failure with sensitivity of 100% and specificity of 87%.Conclusion: Analysis of respiratory-related cortical activation is a non-invasive tool that may help physicians to identify patients ready for extubation.