Thenar oxygen saturation (StO₂) alterations during a spontaneous breathing trial predict extubation failure

Area of Science:

• Critical Care Medicine
• Respiratory Physiology
• Medical Monitoring Technology

Background:

• Weaning from mechanical ventilation (MV) is a significant cardiovascular stress.
• Monitoring regional oxygenation status shows promise in predicting weaning tolerance.
• Skeletal muscle oxygen saturation (StO2) changes during a vascular occlusion test (VOT) were investigated for predicting extubation failure.

Purpose of the Study:

• To determine if StO2 changes measured by near-infrared spectroscopy (NIRS) during a VOT can predict extubation failure.
• To assess the utility of StO2-derived parameters in predicting successful weaning from MV.

Main Methods:

• Prospective study of 206 adult patients with acute respiratory failure on MV for ≥48 hours.
• Continuous StO2 measured non-invasively on the thenar eminence during a 30-min spontaneous breathing trial (SBT).
• VOT performed pre-SBT and at SBT30; calculation of StO2 deoxygenation (DeO2), reoxygenation (ReO2) rates, and hyperemic response (H_AUC).

Main Results:

• 17% of patients (36/206) failed SBT; 13.5% required reintubation within 24 hours.
• Reintubated patients had lower baseline H_AUC and higher relative changes in DeO2 rate (DeO2 Ratio).
• A combined StO2 score (baseline StO2, H_AUC, DeO2 Ratio) achieved an AUC of 0.84 for predicting extubation failure.

Conclusions:

• Extubation failure is linked to alterations in baseline and dynamic StO2 during SBT.
• Monitoring StO2-derived parameters may aid in predicting extubation outcomes.
• NIRS-based StO2 monitoring offers a potential tool for assessing weaning readiness.