| Objective: Continuous blood purification could improve the prognosis of sepsis by decreasing mortality,and it has been widely used in critically ill patients.However the use of continuous blood purification on severe acute pancreatitis(SAP)is controversial.So we do this systematic review and meta-analysis for the answer whether to use continuous blood purification during SAP therapy.Material and methods: Randomized controlled trials and cohort studies comparing outcomes in SAP patients who underwent continuous blood purification therapy or conventional treatment were retreived from Pub Med,EMBASE,the Cochrane Library and Web of Science until October,29,2016 from 1992.The search terms included:((Plasmapheresis OR Hemadsorption OR Hemofiltration OR Hemodiafiltration OR Hemodialysis OR Dialysis OR Serum exchange OR Serum adsorption OR Hemoperfusion OR Cytapheresis OR Blood purification)and acute pancreatitis).The reference lists of relevant articles werescanned for additional trials.Datas were pooled to analyze the effect of continuous blood purification on mortality,inflammatory factor,creatinine,severity of desease,the length of ICU and hospital stay,infected pancreatic necrosis rate and surgical interventions rate.Results: A total of 509 patients in 9 studies met the selection criteria.Four studies were RCTs,while other five were cohort studies.The overall mortality was 18.8%.1.Primary Outcome The use of continuous blood purification was associated with a statistically significant reduction in mortality when compared with conventional treatment in randomized controlled trials(RCTs)[ risk ratio(RR)=0.42,95% confidence interval(CI)(0.22-0.79),P=0.008 ] but with only a trend in cohort studies [ RR=0.65,95%CI(0.41,1.04),P=0.07 ]..2.Secondary Outcomes 2.1 IL-6,CRP,and other inflammatory factor and creatinine IL-6 IL-6 has decreased statistically significant after continuous blood purification therapy after 24 h when compared with conventional group [standard mean difference(SMD)=-0.06,95%CI(-1.13,-0.08),P=0.02].The same result had been seen after therapy for 72 h [ SMD=-0.79,95%CI(-1.19,-0.20),P=0.009 ] with moderate heterogeneity,I2=53%..CRP CRP has decreased statistically significant in continuous blood purification group after treatment for 72 h when compared with conventional group[SMD=-0.93,95%CI(-1.31,-0.56),P<0.00001 ] with no heterogeneity,I2=2% When we make a descriptive analysis of IL-1,IL-8 and creatinine,continuous blood purification could descreased these inflammatory factor and creatinine after therapy for 6 hours.Continuous blood purification could remove inflammatory factor and small soluble molecules.2.2 The severity of desease We make a descriptive analysis of APACHE-II score as there is a big heterogeneity when we pooled data.APACHE-II score may decreased in continuous blood purification group when compared with conventional group.2.3 Infected pancreatitis necrosis There is lower infected pancreatitis necrosis rate in continuous blood purification group when compared with conventional group in pooling data in RCTs[ RR=0.36,95%CI(0.18,0.74),P=0.005 ].But there is no difference between the two groups when pool data in cohort studies[ RR=1.03,95%CI(0.66,1.61),P=0.89 ].2.4 Surgery intervention We found non-difference between continuous blood purification group and conventional group in surgery intervention no matter when pooled data in RCTs [ RR=0.51,95%CI(0.25,1.03),P=0.06 ] or in cohort studies[ RR=0.98,95%CI(0.61,0.56),P=0.93 ].2.5 The length of ICU and hospital stay We make a descriptive analysis of ICU and hospital stay as the data could not be pooled as the different types.The length of ICU and hospital stay may shorten in blood purification as some of the studies reporting a shorter stay when compared with conventional group.Conclusions: From this systematic review and meta-analysis,we can conclude that continuous blood purification could decrease the mortality of SAP patients;and continuous blood purification could decrease inflammatory factor and creatinine,and decrease infected pancreatitis necrosis rate but have no effect on surgery intervention rate.Continuous blood purification could decreased the severity of desease and shorten the length of ICU and hospital stay from the descriptive analysis. |
