Central venous saturation is a predictor of reintubation in difficult-to-wean patients.

Abstract

To evaluate the predictive value of central venous saturation to detect extubation failure in difficult-to-wean patients. Cohort, multicentric, clinical study. Three medical-surgical intensive care units. All difficult-to-wean patients (defined as failure to tolerate the first 2-hr T-tube trial), mechanically ventilated for >48 hrs, were extubated after undergoing a two-step weaning protocol (measurements of predictors followed by a T-tube trial). Extubation failure was defined as the need of reintubation within 48 hrs. The weaning protocol evaluated hemodynamic and ventilation parameters, and arterial and venous gases during mechanical ventilation (immediately before T-tube trial), and at the 30th min of spontaneous breathing trial. Seventy-three patients were enrolled in the study over a 6-mo period. Reintubation rate was 42.5%. Analysis by logistic regression revealed that central venous saturation was the only variable able to discriminate outcome of extubation. Reduction of central venous saturation by >4.5% was an independent predictor of reintubation, with odds ratio of 49.4 (95% confidence interval 12.1-201.5), a sensitivity of 88%, and a specificity of 95%. Reduction of central venous saturation during spontaneous breathing trial was associated with extubation failure and could reflect the increase of respiratory muscles oxygen consumption. Central venous saturation was an early and independent predictor of extubation failure and may be a valuable accurate parameter to be included in weaning protocols of difficult-to-wean patients.