Validity of A new Weaning Index of Discontinuation From Mechanical Ventilation in Intensive Care Unit

Abstract

Abstract Background Failure to wean from mechanical ventilation (MV) is a frequent problem in the intensive care unit (ICU) setting. Herein, we investigate a new WI measured at the initial spontaneous breathing trial (SBT) in order to predict successful liberation from MV in mechanically ventilated ICU cases. Patients and methods This prospective cross-sectional study consisted of two phases; Phase I was designed to create a new WI from the criteria of 60 mechanically ventilated patients, while Phase II aimed to assess the accuracy of that index in another 40 patients. Patients aged older than 18 years who were receiving controlled-mode MV from day 3 to day 14 and planned to be weaned off MV were included in our study. Contrarily, patients with prior history of poor tolerance to SBT, weaning failure were excluded. Additionally, we also excluded patients with neurological or neuromuscular disorders, tracheostomy, pregnancy, or an active COVID-19 infection. Results The incidence of failed weaning was 33.3% in phase I, and 35% in phase II. Pulmonary causes were the most common indication in both groups. Multivariate regression analysis was done for phase I variables, and the following equation was created; (((Cough strength* 0.743) - 1.927) *0.05 + ((PaCO2 (mmHg)* - 0.126) + 6.786) *0.08 + ((mean airway pressure (CmH2O) * -1.304) + 14.119) *0.193 + ((PaO2/FIO2 * 0.268) - 58.555) *0.328 + ((rapid shallow breathing index * -0.485) + 24.406) *0.353). Using a cut-off value of > 0.69 and applying this index in phase II, it showed a mean value of -1.43 and 4.67 in the failure and success groups, respectively (p < 0.001). This new WI with cutoff value (> 0.69) had 88.5% sensitivity, 57.1% specificity, and a 77.5% accuracy to predict the success of weaning from MV. Conclusion We developed a new WI with good sensitivity and moderate specificity for predicting successful weaning from MV in ICU patients. Its use should be encouraged in the ICU setting, especially by less experienced ICU physicians.