The Change of Central Vein Oxygen Saturation Level during Spontaneous Breathing Trial as a Predictor of Successful Extubation in Intensive Care Unit

Weaning from mechanical ventilation is an essential step in the care of critically ill patients. Central venous oxygen saturation (ScvO₂) could reflect tissue oxygenation.

The evaluation of the difference in ScvO₂ values at the beginning and end of the Spontaneous Breathing Trial (SBT) can be used as a predictor of successful extubation in critically ill patients.

This cross-sectional study was conducted in the ICU of Prof. Dr. I.G.N.G. Ngoerah Hospital from July to August 2024. This study involved 42 adult patients aged 18-65 who were using mechanical ventilation during their admission to the ICU. All patients had central venous access, were clinically ready for mechanical ventilation weaning, and could attempt SBT for 30-120 minutes with a rapid shallow breathing index (RSBI) of less than 105.

All patients underwent 30-120 minutes of SBT. ScvO₂ levels were measured at the beginning of SBT (first minute) and at 30 minutes after SBT started, and the change in ScvO₂ level was recorded (ΔScvO₂). Patients with RSBI < 105 measured during SBT were extubated. Extubation failure was defined as the need for re-intubation, or patients died within 48 hours after extubation. Of 42 patients, 37 patients (89.1%) were successfully extubated. There was a significant difference in ΔScvO₂ between successfully extubated patients and those who failed 
(-2.89±1.63 vs. -8.2±4.27; p=0.049). The ROC curve analysis showed that a decrease in ScvO₂ ≤4.5% was the most optimal cut-off for a predictor of successful extubation with a sensitivity of 81.1%, specificity of 60%, positive predictive value of 93.8% and negative predictive value of 70%.

The difference in ScvO₂ between the beginning and after 30 minutes of SBT was a valuable early predictor for successful extubation from mechanical ventilation.