Renin-angiotensin-aldosterone System Changes In Pediatric Severe Sepsis Treated With Continuous Blood Purification

Background:Continuous blood purification(CBP) can block the process from sepsis to multiple organ dysfunction syndrome(MODS) through removing the inflammation medium in the body and maintaining the fluid balance. CBP has become the one of the best tools for critical care medicine to treat and cure the severe infectious diseases.But during the therapy of CBP,the effect of semipermeable membrane is non-selective.It means that not only the toxin and inflammatory reactant can be removed from the body but the medium and small molecules as well. Renin-angiotensin-aldosterone system(RAAS), one of the most important system of vasoactive mediators to keep the blood pressure being stable, containing renin,angiotensin and aldosterone,is also small molecular substances.It is unknown if CBP will effect the RAAS. And it is also unknown how can CBP effect on the blood pressure in the children getting severe sepsis.Objective: To explore the changes of Renin-angiotensin-aldosterone system in pediatric severe sepsis treated with continuous blood purification(CBP).Methods: Prospective study, 35 cases of critically ill children diagnosed with severe sepsis and admitted to PICU of Shanghai Children’s Hospital,Shanghai Jiaotong University from June,2012 to May,2014. Based on the monitoring of vital signs,including central venous pressure(CVP), arterial blood bressure(ABP), mean arterial pressure(MAP), and accepted the conventional therapy,as antibiotics, fluid therapy, patients were treated with CBP by mode of continuous venovenous hemodiafiltration(CVVHDF)or High Volume Hemofiltration(HVHF). Plasma levels of rennin activity, angiontensin Ⅱand aldosterone were measured by radioimmunoassay, before and 24 hours after the CBP. 25 cases of blood samples taken from the children collected from health care for liver function examination were matched as control group.Results: 1. General information:35 cases of critically ill patients as the experimental group,they were all diagnosed severe sepsis.There were 22 male cases(62.8%) and 13 female cases(37.2%) in this group.The age distribution is from 28 months to 7 years old. 27 cases had the PICS scores under 70,and the others had the PCIS scores among 70 to 89. After the general therapy and CBP,11 cases died and mortaility was 31.4%.2. Plasma levels of rennin activity were(2.11±1.93)ug/L,(1.27±1.56)ug/L,(0.37±0.22)ug/L in before, after 24 hs CBP and control group respectively, there were significantly statistic difference(P﹤0.05);3. The levels of angiontensin Ⅱ were(426.78±332.37)ng/L,(364.40±325.51)ng/L,(41.70±10.81)ng/L,in before, after 24 hs CBP and control group respectively, there were significantly statistic difference(P﹤0.05);4. The levels of aldosterone were(255.12±218.18)ng/L,(134.92±104.13)ng/L,(106.88±43.18)ng/L,in before, after 24 hs CBP and control group respectively, there were significantly statistic difference(P﹤0.05);5. 11 cases died and mortaility was 31.4%. After 24 hs of CBP, the MAP improved in 26 cases with septic shock and dopamine dose reduction.Conclusion: The plasma levels of Renin- angiotensin- aldosterone system are increased significantly in critically ill with pediatric severe sepsis. CBP can down-regulated the levels renin, angiotensinⅡand aldosterone, but not worsen the circulation function.