Role of diaphragmatic ultrasonography-based rapid shallow breathing index in predicting weaning outcome from mechanical ventilation device

Background: Rapid shallow breathing index (RSBI) is widely employed to predict weaning outcomes; however, multiple factors can influence its reliability. These include hemodynamic variables, respiratory muscle strength, and the ability to clear secretions through effective coughing. As such, relying solely on a single index may not provide an accurate prediction of weaning success. Several alternative indices have been suggested. Among them, the D-RSBI has emerged as a potentially more accurate tool for evaluating weaning outcomes. Aim of the Study: To investigate the effectiveness of D-RSBI, measured via ultrasonography, in predicting successful weaning in cases deemed ready for extubation. Subjects and Methods: A prospective investigation involved 60 mechanically ventilated cases admitted to the ICU at Benha University Hospital. Each case underwent a full clinical evaluation, including medical history, physical examination, laboratory tests, and imaging. SBT was performed after meeting weaning readiness criteria. DE was assessed using ultrasonography 30 minutes after initiating SBT. RSBI and D-RSBI were measured, and weaning outcomes were documented. ROC analysis was conducted to determine diagnostic accuracy. Results: At a cut-off >2.26 breaths/min/mm, D-RSBI demonstrated superior predictive value, with sensitivity of 92.6%, specificity of 77.8%, and accuracy of 88.3%, compared to RSBI cut-off >42.05 breaths/min/L (sensitivity 88.9%, specificity 66.7%, accuracy 73.3%). A DE threshold >9.5 mm predicted successful extubation with 92.9% sensitivity, 77.8% specificity, and 88.3% accuracy—equivalent to D-RSBI. D-RSBI also exhibited the highest AUC (0.982). Conclusion: D-RSBI offers superior diagnostic accuracy for weaning outcomes compared to RSBI, supporting its use as a valuable index in clinical decision-making.