The Predicting Value Of Diaphragm Ultrasound For Weaning

IntroductionOur present study aimed to evaluate the predictive performance of the diaphragm thickening fraction (DTF) and the averaged diaphragmatic excursion (ADE).Methods55 patients who received mechanical ventilation over 48 hours and met the criteria for a spontaneous breathing trial were included. The excursion of hemi-diaphragm and the changes of diaphragm thickness was measured by ultrasonography during SBT. The patients were classified into success or failure group according to the weaning outcomes. The receiver operating characteristic curves was calculated to evaluate the predictive performance of each index.ResultsDiaphragm thickness difference between two groups of patients had no statistical significance (P=0.46).14 subjects (27.5%) had diaphragmatic dysfunction (DE<10 mm in 11 patients unilaterally and in 3 patients bilaterally). The AUCs of the averaged diaphragm excursion (ADE), the minor diaphragm excursion (MDE), right DE and left DE to predict the success of weaning were 0.97 0.98,0.88, and 0.82, respectively. Optimal cutoff values were 13 mm for the ADE (sensitivity 92%, specificity 99%), 11mm for the MDE (sensitivity 90%, specificity 100%). The cutoff value of DTF>24% was associated with a successful weaning (sensitivity of 74%, specificity of 79% in right; sensitivity of 84%, specificity of 64% in left).Conclusion Diaphragm ultrasound is feasible to predict the outcome of the weaning. The averaged diaphragm excursion and the minor diaphragm excursion may be accurate parameters to predict weaning outcomes.