Central venous oxygen saturation as a predictor of failure of weaning from mechanical ventilation

Background: In the process of weaning from mechanical ventilation (MV), tolerance to a spontaneous breathing trial (SBT) does not completely ensure a favorable outcome. In such conditions, it was possible to predict the result of extubation by the drop of central venous oxygen saturation (ScvO2) readings. Therefore, the evaluation of ScvO2 during SBT may be considered as a novel predictor for weaning success. Patients and Methods: This was a prospective cohort clinical research that involved 50 patients admitted to the respiratory ICU of Abbassia Chest Hospital. Patients were subjected to intubation and MV for the period of 2 successive days or more and followed up for signs of post extubation respiratory failure for 48 h. All patients were evaluated daily for fulfilling of the weaning criteria and were weaned in a two step protocol: SBT for 30 min followed by extubation. ScvO2 was evaluated at the 1st min and at the 30th min of the trial. Hemodynamic and ventilatory parameters were also assessed. Results: 39 (78%) patients were extubated successfully, while 11 (22%) patients failed the extubation process. Logistic regression analysis identified the change in ScvO2 as the only parameter with the ability to distinguish between both probable results of extubation. A reduction of more than 3.8% from the baseline value of ScvO2 was able to independently predict extubation failure (EF) with a sensitivity of 89.74%, a specificity of 90.91, and an odds ratio of 1.48 (95% confidence interval: 1.06–2.07). Conclusion: ScvO2 can successfully predict EF. In addition to being a rapid and accurate method with high sensitivity and specificity, it will help in identifying EF cases and their proper management.