Relationship Between Arterial And Venous Blood Lactic Acid In Early Stage Of Septic Shock And Prognostic Value Of Lactate And Lactate Clearance Rate

Objectives:To analyze the correlation of blood lactate concentration in artery,central vein and peripheral vein of patients with septic shock,and to explore the value of blood lactate and lactate clearance rate in different periods of time in evaluating the prognosis of patients with septic shock.Methods:A total of 60 patients with septic shock admitted to the ICU of Building 3 of the First Affiliated Hospital of Kunming Medical University from June 2020 to February 2021 were selected according to the inclusion and exclusion criteria.According to the "Chinese guidelines for emergency treatment of sepsis/septic shock（2018）".In the first part,blood samples were divided into arterial group,central venous group and peripheral venous group;In the second part,patients were divided into death group and survival group according to 28 day survival.General data,vital signs,laboratory examinations were collected,and parameters of arterial,peripheral vein and central venous blood gas were monitored at ICU admission,6h,12h and 24h after treatment,as well as parameters of arterial blood gas（pH,PO2,PCO2,BE,HCO₃-,SaO2,FiO2,lactic acid concentration）at 48h and 72h.The correlation of lactic acid concentration in arterial,central vein and peripheral venous blood was analyzed,and the evaluation value of blood lactic acid and lactic acid clearance rate at different time in early stage for prognosis of patients with septic shock was discussed.Spss25.0 statistical software package was used for statistical analysis.x²-test was used for count data,t-test was used for normal distribution of measurement data,rank sum test was used for non normal data,Pearson analysis was used for correlation,variance analysis was used for repeated measurement data,and ROC curve was used for diagnostic test.P<0.05 indicated that the difference was statistically significant.Results:1.According to Pearson correlation analysis,there was a correlation between arterial lactic acid and central venous lactic acid at ICU admission and 6h,12h,24h after treatment,with R value between 0.89-0.90 at each time period,P<0.05;there was a correlation between arterial lactic acid and peripheral venous lactic acid at ICU admission and 6h,12h,24h after treatment,with R value between 0.83-0.87 at each time period,P<0.05.2.After drawing ROC curve,the prognostic value of arterial lactic acid in different time was analyzed:initial arterial lactic acid AUC=0.64,P=0.042,6 h arterial lactic acid AUC=0.62,P=0.041,12 h arterial lactic acid AUC=0.64,P=0.034,24 h arterial lactic acid AUC=0.72,P=0.004,48 h arterial lactic acid AUC=0.66,P=0.031,72 h arterial lactic acid AUC=0.63,P=0.036,It can be considered that the value of arterial lactic acid at 24h for prognosis diagnosis is the greatest,with the best cutoff value was 2.42mmol/L,the sensitivity was 0.64,the specificity was 0.66.3.The ROC curve was drawn to analyze the effect of arterial lactic acid clearance rate on the prognosis of patients in different time periods:6 h arterial lactate clearance rate AUC=0.66,P=0.039,12 h arterial lactate clearance rate AUC=0.61,P=0.043,24 h arterial lactate clearance rate AUC=0.74,P=0.002,48 h arterial lactate clearance rate AUC=0.72,P=0.004,72 h arterial lactate clearance rate AUC=0.70,P=0.009 The best cutoff value was 19.57%,the sensitivity was 0.64,the specificity was 0.68.Conclusions:1.There is a correlation between arterial and central venous blood lactic acid levels and between arterial and peripheral venous blood lactic acid levels in patients with septic shock.2.The arterial lactate and lactate clearance rate 24 hours after treatment have a good evaluation value for the prognosis of patients with septic shock.