Preliminary evaluation of a new index to predict the outcome of a spontaneous breathing trial

Abstract

BACKGROUND: The available predictors of spontaneous-breathing-trial (SBT) success/failure lack accuracy. We devised a new index, the CORE index (compliance, oxygenation, respiration, and effort). OBJECTIVE: To compare the CORE index to the CROP index (compliance, rate, oxygenation, and pressure), airway-occlusion pressure 0.1 s after the start of inspiratory flow (P 0.1), and rapid shallow breathing index (RSBI) for predicting SBT success/failure in a critical care environment. METHODS: With 47 mechanically ventilated patients recovering from respiratory failure, of various causes, we prospectively examined the SBT success/failure prediction accuracy and calculated receiver operating characteristic curves, sensitivity, specificity, and likelihood ratios of CORE, CROP, P 0.1, and RSBI. RESULTS: The specificities were CORE 0.95, P 0.1 0.70, CROP 0.70, and RSBI 0.65. The sensitivities were CORE 1.00, CROP 1.00, P 0.1 0.93, and RSBI 0.89. The areas under the receiver operating characteristic curve were CORE 1.00 (95% CI 0.92-1.00), CROP 0.91 (95% CI 0.79-0.97), P 0.1 0.81 (95% CI 0.67- 0.91), and RSBI 0.77 (95% CI 0.62- 0.88). The positive likelihood ratios were CORE 20.0, CROP 3.3, P 0.1 3.1, and RSBI 2.5. The negative likelihood ratios were CORE 0.0, CROP 0.0, P 0.1 0.1, and RSBI 0.2. CONCLUSIONS: The CORE index was the most accurate predictor of SBT success/failure. © 2011 Daedalus Enterprises.