Predictive value of lung ultrasound on extubation success rate in patients with mechanical ventilation / 重庆医学

ABSTRACT

Objective To study the predictive value of lung ultrasound score(LUS) on the extubation success rate in the patients with mechanical ventilation for early identifying the high risk patients with extubation failure and guiding the sequential therapy after extubation.Methods The prospective study method was adopted.Eighty-one cases with mechanical ventilation exceeding 48 h and successfully passing the spontaneous breathing trial(SBT) in EICU were selected.The bedside LUS evaluation was conducted before extubation.The cases were divided into the two groups according to whether successfully weaning.And the LUS differences before extubation were compared between the two groups.The receiver operating characteristic(ROC) curve was used to evaluate the predictive efficiency for extubation failure.Results The age and sex had no statistical difference between the two groups(P＞0.05).In included 81 cases,27 cases were failed to extubation and appeared different degrees of respiratory distress signrespiratory rate(RR) increase,heart rate(HR) increase,SpO2 decrease,etc.,which needed non-invasive mechanical ventilation or high flow nasal cannula oxygen for alleviating respiratory difficulty.In the extubation failure group,10 cases were ineffective by above treatment and then needed reintubation.One case died within 24 h after extubation.Fifty-four cases succeeded in weaning and extubation.The LUS score was positively correlated with RR and PaCO2 (r=0.43,0.62;P＜0.05) and negatively correlated with SpO2 and PaO2(r=-0.76,-0.58;P＜0.05),while it was not correlated with HR and pH value(r=0.15,0.02,P＞0.05).The area under the ROC curve (AUC) of LUS score was 0.90(95％CI0.84-0.95),it could be regarded that the accuracy of LUS for predicting extubation failure rate was stable,its sensitivity was 0.84 and specificity was 0.80.The diagnostic cutoff value was 15.00,if the LUS score exceeding 15 points,the extubation failure rate was significantly increased.Conclusion The LUS score has clinical application value for assessing the extubation success rate in the patients with mechanical ventilation.The patients with high risk of extubation failure can be early identified by the LUS score,which can guide the sequential therapy after extubation.