Ultrasonographic Evaluation of Diaphragmatic Thickness versus Excursion as a Predictor of Weaning in Mechanically Ventilated Patients

Abstract

Abstract Background Best predictor of successful extubation after mechanical ventilation is a matter of debate. Objective The aim of this study was to assess the efficiency of diaphragm thickness and/or diaphragm excursion as measured by means of ultrasound as a predictor of extubation in mechanically ventilated patients in ICU. Methods We performed a prospective study on fifty patients who successfully passed spontaneous breathing trial (SBT). During T-tube spontaneous breathing trial (SBT) we evaluated the right hemidiaphragm excursion by using the M mode and diaphragmatic thickness fraction (DTF%) using B mode, and they were classified in to the successful extubation group and the failure group. Primary outcome: defined as weaning failure and requirement of either noninvasive ventilation or mechanical ventilation. Secondary outcome: To investigate possible factors related to weaning failure Results Of the 50 patients in the study, 35 patients were successfully weaned and 15 failed weaning. The mean diaphragmatic thickness fraction with respect to cut-off value was higher in the failure group during SBT whereas the diaphragmatic excursion with respect to cut off value was less in the failure group during SBT while there was increase in both DTF and diaphragmatic excursion with respect to cut off value in the success group. The diaphragmatic excursion cut-off value predictive of weaning was 10 mm with a specificity 78% and sensitivity 82% respectively and the diaphragmatic thickness cut-off value predictive of weaning was 21.5% with a specificity of 71% and sensitivity of 76% respectively. There was negative correlation between diaphragmatic function and duration of mechanical ventilation. Conclusion The diaphragmatic ultrasonography was found to be a promising tool for predicting the extubation outcome for mechanically ventilated patients.