Fig. 4
From: Validation of the flow index to detect low inspiratory effort during pressure support ventilation
Receiver operating characteristic curve of non-invasive parameters for detecting low inspiratory effort. The area under the receiver operating characteristic curve (AUC) and 95% confidence interval (CI) are shown. By definition of work of breathing (A), the AUC of flow index was significantly higher than those of rapid shallow breathing index (RSBI) (P = 0.002) and minute ventilation (MV) (P < 0.001). By definition of esophageal pressure–time product per minute (B), the AUC of flow index was significantly higher than the other parameters (vs. RSBI: P = 0.002; vs. MV: P < 0.001). By definition of inspiratory muscle pressure (C), the AUC of flow index was significantly higher than the other two parameters (all P < 0.001)