Objective To assess the risk factors associated with extubation failure in patients who had successfully passed a spontaneous breathing trial.Methods Patients receiving invasive mechanical ventilation for over 48 h were enrolled in the study，they were admitted into Emergency ICU of Zhongshan Hospital during May 2006 and Oct.2007.A spontaneous breathing trial was conducted by a pressure support of 7 cm H2O for 30 min.Clinical data were prospectively recorded for the patient receiving full ventilatory support before and after the spontaneous breathing trial.Regarding the extubation outcome，patients were divived into extubation success group and extubation failure group.Results A total of 58 patients with a mean（±SD） age of 69.4±12.7 years passed spontaneous breathing trial and were extubated.Extubation failure occurred in 11 patients（19%）.The univariate analysis indicated the following associations with extubation failure：elderly patients（78.1±7.9 years vs 67.4±15.1years，Plt;0.05），higher rapid shallow breathing index（RSBI） value（83±12 breaths·min-1·L-1 vs 68±19 breaths·min-1·L-1，Plt;0.05）and excessive respiratory tract secretions（54.5％ vs 21.3％，Plt;0.05）.Conclusion Among routinely measured clinical variables，elderly patients，higher RSBI value and amount of respiratory tract secretions were the valuable index for predicting extubation failure despite a successful spontaneous breathing trial.
Objective To determine the usefulness of serial measurements of the rapid shallow breathing index ( f/VT , RSBI) as a predictor for successfully weaning of patients undergoing prolonged mechanical ventilation ( gt; 72 hours) . Methods 76 mechanically ventilated patients were prospectively analyzed. 120-min spontaneous breathing trial was conducted after the patients having fullfiled the traditional weaning criteria, and RSBI were continuously monitored by the ventilator at five time points ( 5, 15, 30,60, and 120 min) . A repeated measure of general linear model in SPSS 15.0 was conducted to analyze the data. Results 62 patients completed 120-minute spontaneous breath trial and in which 20 patients failed weaning. There was no significant difference of RSBI at five time points during weaning ( P gt;0. 05) . But thevariation trends of RSBI during weaning time were significant different between the successful weaning patients and the failed weaning patients ( P lt; 0. 05) . Conclusions In patients undergoing prolonged mechanical ventilation, the variation trend of RSBI is more valuable than single RSBI in the prediction ofsuccessful weaning.
ObjectiveTo investigate the predictive value of diaphragm rapid shallow breathing index (D-RBSI) in weaning from mechanical ventilation in patients with chronic obstructive pulmonary disease (COPD).MethodsSeventy-six patients with COPD who were undergoing mechanical ventilation were enrolled in department of critical care medicine of our hospital from March 2016 to March 2017. The patient underwent spontaneous breathing test (SBT) using CPAP mode after weaning screening. When the SBT had started 10 min or the SBT failed, the patients' respiratory rate (RR) and tidal volume were recorded, and the diaphragmatic displacement (DD) of patients was measured by bedside ultrasound. The ratio of RR to DD (RR/DD) was calculated as D-RBSI, and the predictive value of D-RBSI on weaning results in mechanically ventilated patients with COPD was analyzed by receiver operating characteristic (ROC) curve.ResultsTwenty-eight patients failed weaning procedure. There were no significant differences in age and acute physiology and chronic health evaluation II scores between the successful group and the failed group. The DD of the patients in the successful group was greater than that of the failed group [(22±6) mm vs. (13±5) mm, P<0.001]. RBSI and D-RBSI of the successful group were lower than those of the failure group [RBSI: (40±14) breaths/(min·L)vs. (52±20) breaths/(min·L), P=0.003; D-RBSI: (0.95±0.51) breaths/(min·mm) vs. (1.79±0.83) breaths/(min·mm), P<0.001)]. There was a good correlation between the RBSI and D-RBSI in the two groups (R2=0.778, P<0.001). The area under the ROC curve predicted the weaning result by D-RBSI was higher than RBSI (0.85vs. 0.75, P<0 001="" the="" cutoff="" value="" of="" d-rbsi="">1.13 breaths/(min·mm) to predict weaning failure had a sensitivity of 0.82, and a specificity of 0.81.ConclusionThe rapid shallow breathing index of diaphragm can be effectively used to predict the weaning result of COPD patients during mechanical ventilation.
ObjectiveTo evaluate the predictive value of diaphragmatic rapid shallow breathing index (D-RSBI) for weaning outcome prediction.MethodsThis was a prospective observation study. Respiratory rate (RR) and tidal volume (Vt) were recorded at the end of spontaneous breathing trial, and both M-Mode and B-Mode ultrasonography were used to assess the right diaphragmatic displacement (DD). In parallel, outcome of the weaning attempt, length of mechanical ventilation, length of stay in intensive care unit (ICU) and mortality of ICU were recorded. According to the weaning outcome, the patients were grouped into the successful group and the failed group. The receiver operator characteristic (ROC) curve was used to assess the value of rapid shallow breathing index (RSBI, RR/Vt) and D-RSBI (RR/DD) in predicting weaning failure for ICU patients with mechanical ventilation.ResultsA total of 110 patients recruited in this study. Of them, 73 (66.4%) patients were successfully liberated from mechanical ventilation, and 37 patients failed (33.6%) weaning procedure. The RSBI and D-RSBI of the patients in the failed group were higher than those in the success weaning group (P<0.01). The area under the ROC curves of RSBI and D-RSBI for predicting weaning failure was 0.78 (95% confidence interval 0.69 - 0.87), 0.91 (95% confidence interval 0.85 - 0.97), respectively, a cutoff of RSBI>69 breaths/(L·min) yielded sensitivity of 55% and specificity of 89%, and a cutoff of D-RSBI>1.5 breaths/(min·mm) yielded sensitivity of 87% and specificity of 80%.ConclusionD-RSBI is more accurate than traditional RSBI in predicting the weaning outcome.