The Predictive Value Of Evaluation Of Diaphragmatic Function By Ultrasound In Guiding The Weaning Of ICU Patients

Objective: The failure of weaning from mechanical ventilation of Intensive Care Unit(ICU)are frequent,and Disuse atrophy of the diaphragm during the process of mechanical ventilation,is considered the main factors of the failure of weaning form mechanical ventilation.Diaphragmatic dysfunction has a higher morbidity in ICU patient.Previous tools for the assessment of the diaphragm including X-ray,monitoring transdiaphragmatic pressure(Tdi),magnetic phrenic nerve stimulation,these tools are restricted because of several factors such as Invasive methods?complexity?risk of transport.In recent years,Many studies have found that Evaluation of Diaphragmatic function can be quantified by using bedside ultrasound,with a high accuracy and safety.The purpose of this study is to measurement the DE and DTF of patients facing weaning from mechanical ventilation in ICU with bedside ultrasound,to evaluate the predictive value of diaphragmatic ultrasound in guiding the outcome of mechanical ventilation patients.Method: 41 Patients were including for this study,all of these patients received mechanical ventilation over 48 hours in ICU at Hebei General Hospital from February 2017 to February 2018.The use of-T-piece for spontaneous breathing test(SBT)when meeting the criteria of weaning.Before the weaning,Acute Physiology and Chronic Health Evaluation II(APACHE II),Sepsis related organ failure assessment(SOFA),partial pressure of carbon dioxide(Pa CO2),oxygenation index(Pa O2/Fi O2)should be record,at the thirtieth minutes of spontaneous breathing test,the right hemi-diaphragm was measured with bedside ultrasound,the diaph-ragmexcursion(DE)measured by 3.5HZ probe and the Diaphragm thickening fraction(DTF)is measured at the zone of apposition with 10 MHz linear probe,also the and heart rate and mean arterial pressure was record,divided into success and failure weaning groups according to the results of the weaning.To predict the value of these parameter to weaning with ROC curve.Results: 41 Patients in total and 26 were weaned successfully and 15 were failed,the results of weaning were not associated with Pa O2,Pa CO2,Pa O2/Fi O2(P > 0.05),There was a positive correlation for APACHE?[13.35±4.94 vs.19.67±7.02,P=0.002]and SOFA[5.50(2,11)vs.7.93±3.20,P=0.016] with weaning.The outcome was not statistically significant with heart rates and mean arterial pressure(P > 0.05),There were significant differences about DE[1.23(1.00,2.67)vs.1.03(0.90,2.52),P=0.008]and DTF[0.33±0.07 vs.0.28±0.08,P=0.033]between success and failure weaning groups,the difference was statistically significant.According the ROC curve,the cutoff value of DE to predict successful weaning was1.08 cm,with the 80.77% of the sensitivity and 80.00% of the specificity,and the area under the receiver operating characteristic curve(ROC)was0.751(95%CI:0.571~0.932);For the DTF was 30% of the cutoff value,it's sensitivity and the specificity was65.38% and 60.00%,and It's AUCRoc was0.668(95%CI:0.484~0.852)?Conclusion:1.To measure diaphragm excursion and Diaphragm thickening fraction may be accurate to predict weaning outcomes of ICU ventilator patients.2.The APACHE ? and SOFA may have negative correlation with the results of weaning.