Statistical analysisStatistical analyses were performed with the Scientific Package for Social Science for Windows (SPSS, version 13.0, SPSS Inc, Chicago, IL, USA). Continuous data were expressed as mean �� standard deviation unless otherwise specified. Percentage was calculated for categorical variables. Student’s t test was used to compare the means of continuous data, whereas Chi-squared Sorafenib Raf-1 test or Fisher’s exact test was used to analyze categorical proportions. Then we used backward stepwise likelihood ratio model of Cox proportional hazard method to analyze the independent predictors for in-hospital mortality. The independent variables were selected for multivariate analysis if they had a P �� 0.1 on univariate analysis. The basic model-fitting techniques for (1) variable selection, (2) goodness-of-fit assessment, and (3) regression diagnostics (e.

g., residual analysis, detection of influential cases, and check for multicollinearity) were used in our regression analyses to ensure the quality of analysis results. Specifically, we used the stepwise variable selection procedure with both significance level for entry and significance level for stay set to 0.15 or larger to select the relevant covariates into the final Cox proportional hazards model. Also, we did an additional analysis adjusting for three clinical relevant variables (namely, sepsis before RRT, mechanical ventilation, and diabetes) regardless of P value because they were considered important. Furthermore, we did the analysis comparing sRIFLE categories against each other for the relative risk (RR) for in-hospital mortality.

In statistical testing, two-sided P value less than 0.05 was considered statistically significant.Finally, Kaplan-Meier survival curves with log-rank test was drawn to express the differences of patient survival between the two groups (ED versus LD).ResultsFive hundred and ninety-six patients were screened. Patients on chronic dialysis (n = 165), those without surgery prior to RRT initiation (n = 87), or those whose surgery did not involve abdominal cavities (n = 244) were excluded. A 44-year-old male patient receiving kidney transplantation and an 85-year-old female patient with an extremely long hospital stay period (740 days from ICU admission to death, and 727 days from RRT initiation to death) were also excluded. Figure Figure11 shows the flowchart of patient gathering and selecting.

Finally, a total of 98 patients (41 female, 57 male; mean age 66.4 �� 13.9 years) Cilengitide were selected and followed until 30 June, 2006. Of the 98 patients who underwent acute RRT following major abdominal surgery, most patients (57.1%) underwent elective surgery. Surgery of the hepatobiliary organ was performed in 26 patients (26.5%), upper GI tract in 28 (28.6%), lower GI tract in 29 (29.6%), urological organs in 9 (9.2%), and other sites in 6 (6.1%).