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 diaphragmatic rapid shallow
breathing index (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
patients admitted to the ICU at Benha University Hospital. Each
patient underwent a full clinical evaluation, including medical
history, physical examination, laboratory tests, and imaging.
Spontenous breathing trial (SBT) was performed after meeting
weaning readiness criteria. Diaphragmatic excursion (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.