The Correlation Between The Initial Concentration Of Citrate And The Control Rate Of Post-filtration Ionized Calcium As Well As The Filter Life :A Retrospective Study

Background:The safety and efficacy of regional citrate anticoagulation(RCA)in the extracorporeal circuit in patients on continuous renal replacement therapy(CRRT)has been demonstrated.Compared with systemic heparin anticoagulation,RCA has fewer new blood events and longer filter life.RCA is recommended in the anticoagulation guidelines for renal replacement therapy consensus.At present,a series of RCA protocols have been introduced,and there is no uniform recommendation of initial concentration of citrate.In order to explore the anticoagulant effect under different concentration of citrate,this study will compare three RCA protocols with different initial concentration of citrate,hoping to find the ideal initial concentration of citric acid and optimize the RCA protocol.Objectives:Three RCA protocols were studied in this study: Group A citrate concentration <3.0mmol/L,group B citrate concentration 3.0mmol/L,and group C citrate concentration > 3.0mmol/L.By comparing the control rate of post-filter ionic calcium,the correlation between the concentration of citrate and the filter life,the difference of blood acid-base state and electrolyte of the three RCA protocols,it is hoped to find out the ideal initial concentration of citrate,so that the concentration of post-filter ionic calcium within the target range(0.25-0.40mmol/L)with the maximum probability,and optimize the RCA scheme.Thus reducing unnecessary post-filter ion calcium monitoring.Subjects and methods:Patients in need of continuous renal replacement therapy(CRRT)from the first ward of Intensive Care Department of our hospital from September 2021 to December2022 were retrospectively selected according to the nanation criteria.Inclusion criteria:1)Age greater than 18 years old;2)Receive continuous venovenous hemofiltration dialysis(CVVHDF),use post dilution mode for replacement solution,and use regional citrate anticoagulation;3)Plasma filtration fraction<25%.The exclusion criteria for this study include: 1)missing post-filtration ionized calcium data after 2 hours of CRRT activation;2)During the treatment period,patients accept heparin therapy while using citric to maintain anticoagulation in the extracorporeal circulation pipeline.The primary end points of this study were the compliance rate of post-filtration ionized calcium in three RCA regimens with different initial citric concentrations,and the correlation analysis of citric concentration with filter life.Secondary outcomes were filter lifetime,PH status,and electrolyte differences.For continuous variables,independent sample t test was used to compare the variation values of data conforming to normal distribution between the two groups.For data that did not conform to normal distribution,nonparametric test was used to compare the variation values between the two groups.Data for non-normal distributions are described as median.Classification variables represented as frequency(percentage).The test direction was bilateral,and P < 0.05 was considered statistically significant.Results:In this study,there are 70 patients receiving continuous venous venous hemofiltration dialysis(CVVHDF)treatment and 191 pipelines.According to the initial citric concentration,there are 16 pipelines in group A(including 14 cases of2.8mmol/L,1 case of 2.4mmol/L,and 1 case of 2.6mmol/L),105 pipelines in group B,70 pipelines in group C(including 54 cases at 3.2mmol/L,14 cases at 3.4mmol/L,and 2 cases at 3.6mmol/L).By comparing the data of three RCA protocols,it was found that the initial concentration of citric had a positive correlation with the filter life over48 hours.There was no statistical difference in the concentration of post-filter ion calcium and the compliance rate of post-filter ion calciu among the three groups of RCA schemes,also the compliance rate was lower than 30%.The concentration of bicarbonate in peripheral blood of the group with higher concentration of citric was higher.Conclusions:High concentration of citric has a protective effect on filter lifespan of over 48 hours.When the concentration of citric is 2.8mmol/L-3.4mmol/L,the compliance rate of the first post-filter ion calcium is relatively low.A citrate anticoagulant regimen with a high concentration of citric can simplify the alkali supplementation regimen.