The Predictive Value Of DD Combined With LUBS,D-RSBI For Mechanical Ventilation Weaning

Background:Mechanical ventilation is widely used in critically ill patients and is also an important means of respiratory support.Weaning from the ventilator is a key step to patient.Timely and effective weaning from the ventilator can reduce the complications related to mechanical ventilation,reduce hospitalization time,decline the cost of hospitalization,and avoid re-intubation.At the beginning of mechanical ventilation,the patient should be judged on the possibility of weaning from the ventilator.Experimental weaning is allowed when the patient meets the screening criteria for daily weaning.At present,a number of indicators have been used to predict the outcome of weaning,among which the most widely used is the shallow rapid respiration index（RSBI）.However,RSBI has some disadvantages,such as low specificity.Therefore,finding the parameters with higher value for predicting weaning has become a research goal for scholars at home and abroad.Ultrasound has been widely used in critically ill patients in recent years because of its advantages,such as speed,convenience and no radiation,providing a visual tool for clinicians to timely assess the condition of patients.Research shows that diaphragmatic ultrasound can monitor diaphragmatic function through measuring diaphragmatic displacement（DD）,and reflect the breathing condition of patients through lung ultrasound B-line score（LUBS）.Both diaphragmatic ultrasound and pulmonary ultrasound are good parameters to predict weaning,but separate diaphragmatic ultrasound and pulmonary ultrasound may be missed in patients with some special diseases,which increases the failure rate of weaning.Therefore,some scholars suggest combining DD with LUBS.Studies have shown that the combination of DD and LUBS can comprehensively evaluate the functional status of diaphragm and lung,and can more accurately evaluate the outcome of weaning than a single index.Diaphragmatic rapid shallow breathing index（D-RSBI）is a new indicator obtained by foreign scholars in 2016,replacing VT with DD measured by ultrasonic according to the calculation formula of RSBI（RR/VT）,which has good value in predicting the weaning.Objective:There is still a lack of a sensitive and specific parameter to accurately evaluate the outcome of weaning.Once the weaning fails,it will bring serious burden to the patients and their families.Scholars at home and abroad have been looking for ways to predict a higher success rate of the weaning and reduce the risk of the weaning failure.Both DD combined with LUBS,D-RSBI have shown good predictive value in predicting weaning.At present,there are few studies on these two aspects,and no studies have compared their diagnostic efficiency in predicting weaning.By comparing,this study seeks for a more accurate parameters to predict the weaning outcome.Methods:To collect data from June 2019 to December 2020 in EICU of Hebei university affiliated hospital,which receiving invasive mechanical ventilation.Collect patients’information,such as ID,age,gender,vital signs,arterial blood gas analysis,brain natriuretic peptide（BNP）,electrolytes,procalcitonin（PCT）and assessment of acute physiology and chronic health evaluationⅡscore（APACHEⅡ）.DD,LUBS,respiratory rate（RR）and tidal volume（VT）were measured during spontaneous breathing test（SBT）for 30 minutes.According to the weaning results,it was divided into two group:the successful group and the failed group.The differences of each detection index in the two groups were compared,and the ROC curve was drawn to detect the predictive ability of each index.Spearman correlation analysis was conducted to compare the correlation between detection indexes.Results:The age,PCT,BNP and APACHE II of the group with failure were higher than those in the success group,and the mean arterial pressure and Pa O₂ were lower than those in the success group（P<0.05）,while the others were not statistically significant,such as p H,WBC,hematocrit,sodium,potassium,creatinine,lactic acid between the two groups（P>0.05）.There were statistical differences in RSBI,D-RSBI,DD combined with LUBS between the two groups（P<0.05）.（2）RSBI,D-RSBI,DD combined with LUBS can all be used to predict weaning failure.The area under the ROC curve of D-RSBI predicting weaning failure was 0.917,the best threshold value was 1.34,the sensitivity was 90.91%and the specificity was 82.72%.The area under the ROC curve of DD combined with LUBS was 0.896,the sensitivity was 86.36%,and the specificity was 79.01%.Finally,the area under the ROC curve that RSBI predicts the failure of weaning was 0.825,the optimal threshold was 54.59,the sensitivity was 72.73%,and the specificity was 87.65%.（3）There was a correlation between D-RSBI and RSBI（r=0.636,P<0.05）,there was no correlation between DD combined with LUBS and RSBI（P>0.05）.Conclusion:D-RSBI,DD combined with LUBS are all good parameters for predicting weaning with similar predictive value,but D-RSBI is more suitable for clinical practice because of its simple operation,shorter time consuming.