Late Breaking Abstract - Abdominal Muscle Function During Spontaneous Breathing Trials to Predict Extubation Failure

Abstract

Background: Ultrasound measurements of abdominal muscle thickening fraction (TF) may be useful to monitor abdominal muscle activity and function in mechanically ventilated patients. Aims: To quantify TF of the abdominal muscles during a spontaneous breathing trial (SBT) and to determine whether abdominal muscle TF during coughing predicts extubation success. Methods: In 57 mechanically ventilated patients, TF of right external oblique (EO), internal oblique (IO), transversus abdominis (TrA) and rectus abdominis (RA) were measured before and during SBT and during coughing. Discriminative validity to predict reintubation was assessed using ROC curve analysis. Results: TF during the SBT varied between patients. At 5’ into the SBT, TF was significantly higher in patients who failed the SBT compared to patients who passed for TFIO (difference 7.2%, 95%CI 2.2–13.2), TFTrA (difference 13.2%, 95%CI 0.9–24.8), but not for TFEO or TFRA. Compared to healthy subjects, TrA, IO and RA end-inspiratory thickness was significantly lower (p Conclusions: IO and TrA TF is significantly higher in patients who are failing an SBT compared to patients who are passing, consistent with elevated expiratory muscle effort. Abdominal muscle thickening during coughing may identify patients at high risk for reintubation