Data analysis StO2 curves were analyzed by Inspectra Analysis Program V2.0. Linear regression was used to extrapolate the rate of Δdown- and Δup- StO2 during UIRT. Data was expressed as median ± standard deviation (SD). Non parametric test: Kolmogorov-Smirnov, Wilcoxon and Fisher exact test were used (SPSS 10.0 for Windows ™, SPSS Inc., USA). Spearman correlation test was used to determine correlation. To compare muscle tissue StO2 variables during UIRT, ScvO2 and SvO2: bias, systemic disagreement between the measurements (mean difference between two measurements), and precision, the random error in measuring (standard deviation of bias), were calculated. The limits of agreement were arbitrary set by Bland and Altman as the bias± 2 SD. To determine the variables independently associated with survival uni- and multivariate logistic regression (Forward Stepwise (Likelihood Ratio)) was used. The p value of <0.05 (2-tailed) was considered statistically significant.