The Value Of Ultrasound Evaluation Of Diaphragm Function In Predicting Weaning Outcomes Of Children With Mechanical Ventilation In PICU

Objective: The diaphragm ultrasound parameters of children with mechanical ventilation（MV）in pediatric intensive care unit（PICU）and healthy children were measured by B-mode and M-mode ultrasonography,to evaluate the changes of diaphragm function in children with MV,analyze the correlations between diaphragm ultrasound parameters and duration of MV,and explore the application value of diaphragm ultrasound parameters in predicting weaning outcomes of children with MV.Methods: 50 critically ill children admitted to PICU of Lanzhou University Second Hospital with MV were selected as the case group（MV group）.According to the clinical weaning outcomes,the MV group was divided into the successful weaning group（n = 34）and the failed weaning group（n = 16）.Additionally,41 healthy children with matched age and gender were selected as the normal control group.The general data of the normal control group and the MV group were collected.Diaphragm ultrasound parameters were measured and calculated,including diaphragm excursion（DE）,diaphragm thickness（DT）,diaphragm thickening fraction（DTF）,diaphragm excursion-rapid shallow breathing index（DE-RSBI）,and diaphragm thickening fraction-rapid shallow breathing index（DTF-RSBI）.In addition,collected the clinical data such as the reasons of MV,the duration of MV and laboratory indexes of the MV group.Firstly,diaphragm ultrasound parameters of the normal control group and the MV group were compared.Then,general data,clinical data,laboratory indexes and diaphragm ultrasound parameters were compared between the successful weaning group and the failed weaning group.To analyze the correlations between diaphragm ultrasound parameters and the duration of MV.Finally,the optimal cut-off value,sensitivity and specificity of diaphragm ultrasound parameters in predicting weaning outcomes were obtained by drawing the receiver operating characteristic（ROC）curve.Results: 1.The DE,DT at end of inspiratory,DT at end of expiratory,and DTF of the normal control group were higher than those of the MV group,while DE-RSBI and DTF-RSBI were lower than those of the MV group（all P < 0.001）.2.The comparison results of each index between the successful weaning group and the failed weaning group showed that duration of MV was longer in the failed weaning group（P < 0.001）.Compared with the failed weaning group,the successful weaning group had higher DE and DTF,but lower DE-RSBI and DTF-RSBI（all P<0.05）.And there were no significant differences in general data and laboratory indexes between the two groups（all P > 0.05）.3.Correlation analysis results showed that DE was negatively correlated with duration of MV（r=-0.391,P=0.005）,while DE-RSBI was positively correlated with duration of MV（r =0.423,P=0.002）.4.According to the ROC curve,the cut-off value of DE in predicting weaning success was 8.05 mm,and the AUC was 0.885（95% CI: 0.793-0.977）,the sensitivity and specificity were 82.4% and 87.5% respectively.The cut-off value of DTF in predicting weaning success was 26.1%,and AUC was 0.749（95%CI: 0.591-0.907）,the sensitivity and specificity were 67.6% and 81.2% respectively.The cut-off value of DERSBI in predicting weaning failure was 3.73 breaths/（min·mm）,and AUC was 0.811（95%CI: 0.673-0.948）,the sensitivity and specificity were 68.8% and 85.3%respectively.The cut-off value of DTF-RSBI in predicting weaning failure was 107.97breaths/min,and AUC was 0.709（95%CI:0.531-0.886）,the sensitivity and specificity were 68.8% and 76.5% respectively.Conclusion: Diaphragm ultrasound can effectively evaluate diaphragm atrophy and systole dysfunction in children with mechanical ventilation,diaphragm ultrasound parameters such as DE,DTF,DE-RSBI and DTF-RSBI can be used as effective indicators to predict weaning outcomes.As a rapid,accurate and unrestricted technique,diaphragm ultrasound can provide an important reference for pediatricians to make weaning decisions.