Abstract: Background: Sepsis，characterized by rapid progression and high mortality, is a common critical disease in PICU. It remains controversial whether the combination of routine supportive therapy and continuous blood purification (CBP) can improve the prognosis of children with septic shock. Objective: To observe the effect of CBP on the prognosis and fluid overload in sepsis shock children. Design: Non-randomized controlled study. Methods: Septic shock children at the age of one month to 14 years, admitted to PICU at HeBei Children's Hospital from May 2015 to May 2020, were enrolled. A total of 95 children were included into analysis with 64 in CBP group and 30 in non-CBP group. CVVH or CVVHDF mode was applied with fluid displacement rate of 30~50 mL·kg-1·h-1. The following indicators were compared—7-day and 30-day survival rate, fluid overload ration of CBP at 72 h, vasoactive agent score, heart rate, P/F value, amount of lymphocytes and their subtypes, IL-6, PCT and duration of hospital stay. Main outcome measures: 7-day survival rate. Results: CBP group included 64 cases with 44 cases in 0~24 h subgroup and 20 cases in 24~48 h subgroup, and non-CBP included 30 cases. There was no statistical difference in age, male percentage, PRISM Ⅲ score, ratio of invasive mechanical ventilation, as well as vasoactive agent score, heart rate, P/F value, amount of lymphocytes and their subtypes, IL-6 and PCT. The survival rates of 7-day and 30-day in CBP group (82.8%, 78.1%) were higher than those of non-CBP group (70.0%,60.0%) with P value of 0.022 and 0.038 respectively. The fluid overload ratio at 72 h was 31.2% in CBP group, lower than 63.3% in non-CBP group (P=0.003). The amount of lymphocytes and their subtype at 72 h in CBP group was higher than that of non-CBP group, with statistical differences. There were no statistical differences in vasoactive agent score, heart rate, P/F value, IL-6 and PCT between CBP group and non-CBP group. At 72 h, fluid overload ratio（P=0043）and IL-6 level（P=0.007）were lower, and the amount of lymphocytes and their subtypes was higher in 0~24 h subgroup with statistical differences. Conclusion: CBP is superior in elevating survival rate, keeping fluid balance, decreasing use of vasoactive agent, relieving immune inhibition in septic shock children, and the early use of CBP has significant efficacy.

Key words: Continuous blood purification technology, Sepsis shock, Fluid overload, Child