Ventilation distribution during spontaneous breathing trials predicts liberation from mechanical ventilation: the VISION study.

Summary

Prospectively measured EIT during SBT showed that a ventral-to-dorsal ventilation difference >20% at 5 minutes predicts liberation failure with good accuracy. EIT can augment clinical assessment by identifying at-risk patients early in the SBT.

Key Findings

• Among 98 patients, liberation success had consistently smaller ventral-to-dorsal ventilation differences throughout SBT (p<0.0001).
• A ventral–dorsal difference >20% at 5 minutes predicted liberation failure (sensitivity 71%, specificity 78%, PPV 81%) in validation cohort.
• 13.5% of extubated patients required reintubation, underscoring the need for better predictors.

Clinical Implications

In ICUs with EIT, monitor ventral–dorsal ventilation balance during SBT; a >20% imbalance at 5 minutes should prompt caution, optimization (e.g., positioning, support), or prolonged SBT before extubation.

Limitations

• Single-study setting with modest sample size; EIT availability may limit generalizability.
• Threshold derived within study cohorts; external, multicenter validation needed.

Future Directions

Multicenter validation and integration with clinical/respiratory mechanics to build robust weaning prediction tools; evaluate whether EIT-guided strategies reduce reintubation.