Comparison of rapid shallow breathing index versus ultrasonographic guided diaphragmatic thickness fraction as weaning indices on mechanically ventilated patients

Abstract

Background: The discontinuation or weaning from mechanical ventilation is an important clinical issue which is associated with lot of complications and patient discomfort. So we need a reliable and feasible method for early, safe and effective liberation of patients from mechanical ventilation. The objectives of our study are to determine sensitivity and specificity of rapid sequence breathing index (RSBI) and ultrasonography (USG) guided diaphragmatic thickness fraction (DFT) as weaning indices and to compare their effectiveness. Methods: The study was carried out on mechanical ventilated patients, when they were considered ready for weaning and the underlying disease is stable or resolving. The measurements of RSBI and DFT using USG were carried out. Weaning was taken as successful if the patients could maintain spontaneous breathing at least 48hrs after extubating, otherwise weaning was classified as failed. Results: RSBI and DTF group showed no statistically significant difference in extubation of mechanically ventilated patients in the intensive care unit (ICU). RSBI showed sensitivity of 96%, specificity of 74.4%, positive predictive value of 88.2%, negative predictive value of 80.5%, and accuracy of 87.2%, and DTF showed sensitivity of 96%, specificity of 69.7%, positive predictive value of 82.4%, negative predictive value of 78.9% and accuracy of 81.9%. Conclusion: In our study since there was only one reintubation in each of the groups, that is failure of weaning of one case each in RSBI and DTF groups, both RSBI and DTF has the same sensitivity of 96%, RSBI has better specificity of 74.4% than DTF of 69.7%, RSBI having a better accuracy of 87.2% than DRF which has an accuracy of 81.9%. We conclude that both the methods are equally effective when used as weaning indices for extubation of mechanically ventilated patients.