AIM: To investigate extravascular lung water indexed to predicted body weight(EVLWIp) and actual body weight(EVLWIa) on outcome of patients with severe sepsis.METHODS: Transpulmonary thermodilution was prospectively used to measure cardiovascular hemodynamics, EVLWIp and EVLWIa via an arterial catheter placed in each patient within 48 h of meeting the criteria for severe sepsis from a medical intensive care unit(ICU) at a university affiliated hospital. Survival was the single dependent variable. In order to examine and compare the predictive power of EVLWIp, EVLWIa and other clinically significant factors in predicting the inhospital survival status of severe sepsis patients in the medical ICU, a receiver operating characteristic(ROC) curve method to analyze the significant variables and the area under the ROC curve(AUC) of the variables, P value and 95%CI were calculated.RESULTS: In total, 33 patients were studied. In the ROC curve method analyses, EVLWIp(the AUC: 0.849; P = 0.001, 95%CI: 0.72-0.98) was as predictive for inhospital survival rate as variables with EVLWIa(AUC, 0.829; P = 0.001, 95%CI: 0.68-0.98). The proportion of patients surviving with a low EVLW(EVLWI < 10 m L/kg) was better than that of patients with a higher EVLW, whether indexed by actual(HR = 0.2; P = 0.0002, 95%CI: 0.06-0.42) or predicted body weight(HR = 0.13; P < 0.0001, 95%CI: 0.05-0.35) during their hospital stay with the Kaplan-Meier method(76% vs 12.5%, respectively).CONCLUSION: This investigation proposed that EVLWIp is as good a predictor as EVLWIa to predict inhospital survival rate among severe sepsis patients in the medical ICU. To investigate extravascular lung water indexed to predicted body weight (EVLWIp) and actual body weight (EVLWIa) on outcome of patients with severe sepsis. METHODS: Transpulmonary thermodilution was prospectively used to measure cardiovascular hemodynamics, EVLWIp and EVLWIa via an arterial catheter in each patient within 48 h of meeting the criteria for severe sepsis from a medical intensive care unit (ICU) at a university affiliated hospital. Survival was the single dependent variable. In order to examine and compare the predictive power of EVLWIp, EVLWIa and other clinically significant factors in predicting the inhospital survival status of severe sepsis patients in the medical ICU, a receiver operating characteristic (ROC) curve method to analyze the significant variables and the area under the ROC curve (AUC) of the variables, P value and 95 % Of the patients were studied. In the ROC curve method analyzes, EVLWIp (the AUC: 0.849; P = 0.001, 9 5% CI: 0.72-0.98) was as predictive for inhospital survival rate as variables with EVLWIa (AUC, 0.829; P = 0.001, 95% CI: 0.68-0.98). The proportion of patients survived with a low EVLW m L / kg) was better than that of patients with a higher EVLW, whether indexed by actual (HR = 0.2; P = 0.0002, 95% CI: 0.06-0.42) or predicted body weight 95% CI: 0.05-0.35) during their hospital stay with the Kaplan-Meier method (76% vs 12.5%, respectively) .CONCLUSION: This investigation proposed that EVLWIp is as good a predictor as EVLWIa to predict inhospital survival rate among severe sepsis patients in the medical ICU.