[Negative fluid balance predicts survival in patients with septic shock]

To explore the change of fluid balance in patients with septic shock for seven continuous days and examine its effect on clinical prognosis.

A retrospective study was conducted for 105 patients with septic shock admitted into our intensive care unit (ICU) from May 2013 to February 2014. They were divided into non-survivors and survivors. Their baseline data, net balance quantity of fluid for seven continuous days and laboratory results were recorded and analyzed.

Among them, 28 patients died. Duration of mechanical ventilation, sequential organ failure assessment (SOFA) score and acute physiology and chronic health evaluation II (APACHE II) score were all lower in survivors than those in non-survivors (6 d vs 11 d, P = 0.002; 7 d vs 9 d, P < 0.001; 15 vs 19, P = 0.035). Yet hospitalization time in survivors was longer than that in non-survivors (30 d vs 18 d, P = 0.026) . According to trend graph on net balance of each day, the cumulative net negative fluid balance in survivors increased over time while it remained stable in non-survivors. Among seven days, the cumulative net fluid balance at Day 7 was most negatively correlated with survival days (r = -0.278, P = 0.006). Logistic regression analysis showed that SOFA score and cumulative net balance at Day 7 were the independent prognostic risk factors for septic shock. Moreover, at Day 7, no statistically significant inter-group difference existed in serum creatinine, alanine aminotransferase, PO(2)/FIO(2) and cardiac troponin I levels. But serum total bilirubin in survivors was lower than that in non-survivors (16.0 vs 27.9, P = 0.031).

Cumulative net negative balance quantity of fluid in survivors was much more than that in non-survivors. SOFA score and net balance quantity of fluid at Day 7 were the independent prognostic risk factors for septic shock. Cumulative net fluid balance at Day 7 was most negatively correlated with survival days. No significant inter-group difference existed in organ function at Day 7.