Role of diaphragmatic rapid shallow breathing index in predicting weaning outcome in patients with acute exacerbation of COPDRole of diaphragmatic rapid shallow breathing index in predicting weaning outcome in patients with acute exacerbation of COPD
Ahmad Abbas, Sameh Embarak, Mohammad Walaa, Samah Mohamed Lutfy
Chest Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
Background: The diaphragmatic rapid shallow breathing index (D-RSBI), which is the ratio between respiratory rate (RR) and the ultrasonographic evaluation of diaphragmatic displacement (DD), is a new and promising tool to predict weaning outcome. Its accuracy in predicting weaning failure, in ready-to-wean acute exacerbation COPD (AECOPD) patients, needs to be evaluated.
Patients and methods: A prospective observational study was carried out on ready-to-wean AECOPD patients. During a T-tube spontaneous breathing trial (SBT) evaluation of the right hemidiaphragm displacement (ie, DD), M-mode ultrasonography to calculate the D-RSBI, as well as the RSBI (RR/tidal volume [VT]) were carried out simultaneously. Outcome of the weaning trial was recorded. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic accuracy of D-RSBI and RSBI.
Results: A total of 50 AECOPD patients requiring mechanical ventilation for more than 48 h who were ready to perform a SBT were included. Of these, 37 (74%) were successfully liberated from mechanical ventilation. Among the 13 patients who failed the weaning trial, 8 (62%) failed the SBT and reconnected to the ventilator, 2 (15%) were reintubated within 48 h of extubation and 3 (23%) required NIV support within 48 h of extubation. The areas under the ROC curves for D-RSBI and RSBI were 0.97 (p<0.001) and 0.67 (p<0.06), respectively.
Conclusion: D-RSBI (RR/DD) is superior to the traditional RSBI (RR/VT) in predicting weaning outcome in AECOPD patients.
Keywords: rapid shallow breathing, diaphragmatic displacement, ultrasonography, spontaneous breathing trial, weaning