Clinical Study Of The Occurrence And Intervention Of Acute Kidney Injury Associated With Cardiac Surgery

Part 1.Incidence and risk factors of cardiac surgery-associated acute kidney injuryObjective : To investigate the incidence and related risk factors of cardiac surgery-associated acute kidney injury(CSA-AKI).Methods : A retrospective analysis of 1575 patients undergoing cardiac surgery with cardiopulmonary bypass(CPB)between January 2009 and December 2011 in Nanjing First Hospital,was recruited.Univariate and multiple Logistic regression models were employed for determining the association between the development of CSA-AKI and risk factors.Multiple Cox-proportional hazards modeling was used to evaluate the impact of CSA-AKI on the mortality of ICU and hospital length of stay.Results:Among this cohort,of 1575 patients,534(33.90%)occurred AKI.A total of 22(1.40%)patients required renal replacement therapy.The overall in-hospital mortality rate was 1.27%(20 of 1575).Logistic regression analysis showed that mechanical ventilation duration of ?9 hours(P<0.001),CPB duration of ?110min.(P=0.008),more erythrocytes transfusion(P<0.001)and postoperative body temperature greater than38°C within 3 days(P=0.037)were found to be independent risk factors of CSA-AKI,while ulinastatin use was associated with lower incidence for CSA-AKI(P<0.001).CSA-AKI was significantly related to high in-hospital mortality(P<0.05),especially in patients requiring RRT(P<0.001).Conclusions:The prevalence of CSA-AKI in patients form this cohort was 33.90%.Mechanical ventilation duration,erythrocytes transfusion and postoperative body temperature greater than 38°C within 3 days were independent risk factors of CSA-AKI.Ulinastatin was associated with lower incidence of CSA-AKI.Part 2.Research on the protective effects of ulinastatin on cardiac surgery-associated acute kidney injuryObjective: To investigate the protective effect of ulinastatin administration on cardiac surgery-associated acute kidney injury(CSA-AKI)in patients undergoing heart surgery with cardiopulmonary bypass(CPB).Methods: A retrospective,propensity score matched cohort study was used to evaluate the outcomes of the patients underwent cardiac surgery after ulinastatin administration during CPB.A multivariate Logistic regression model was employed to determine the association between the use of ulinastatin and the incidence of CSA-AKI.Results: The control group produced higher incidence of CSA-AKI(41.22% vs.29.29%,P=0.006)and required more frequent use of renal replacement therapy(RRT)(2.86% vs.0.41%,P=0.032),compared with the ulinastatin group.However,no significant differences were shown in mortality,the length of stay in ICU and length of hospital stay between the two groups(P > 0.05).According to multivariate Logistic regression analysis,administration of ulinastatin played a protective role in the protection and treatment of CSA-AKI(OR 0.71 95%CI 0.56-0.90,P=0.005).Conclusions: Clinical use of ulinastatin can decrease the risk of CSA-AKI in patients undergoing cardiac surgery with CPB and improve their prognosis.Part 3.Perioperative factors associated with requirements of renal replacement therapy following cardiac surgery-associated acute kidney injuryObjective:To explore the incidence of renal replacement therapy(RRT)in patients with cardiac surgery-associated acute kidney injury(CSA-AKI)and related risk factors during perioperative period.Methods : We retrospectively analyzed the clinical data of the patients with renal replacement therapy after cardiac surgery treated in Nanjing First Hospital in the period from Jun 2008 to Dec 2012.Results:In the present study,2810 consecutive patients who underwent cardiovascular surgery from 2008 to 2012 at a single institution were reviewed.A total of 982(34.95%)had acute kidney injury and 33 patients(1.17%)required RRT.Multivariate Logistic regression analyses showed that female(OR 0.31 95%CI 1.36-7.04,P=0.007),combined with history with COPD(OR 7.60 95%CI 1.87-30.90,P=0.005),CKD(OR7.78 95%CI 2.55-23.74,P<0.001),lower left ventricular ejection fraction(OR 0.9695%CI 0.93-0.99,P=0.019),higher serum creatinine(OR 7.78 95%CI 2.55-23.74,P< 0.001),lower left ventricular ejection fraction(OR 1.01 95%CI 1.00-1.01,P <0.001),more red cell transfusion(OR 1.12 95%CI 1.08-1.17,P<0.001)and over38°C postoperation(OR 3.35 95%CI 1.45-7.72,P=0.005)were associated with a requirement for renal replacement therapy after cardiac surgery.Conclusions:The need for renal replacement therapy patients after cardiac surgery was high,and was closely related to many risk factors in the preoperative period.Part 4.Effect of recombinant human erythropoietin on prevention of cardiac surgery-associated acute kidney injuryObjective: To investigate the renoprotective role of recombinant human erythropoietin(r Hu EPO)in early intervention of cardiac surgery associated acute kidney injury(CSA-AKI).Methods: A single-center,randomized controlled trial(RCT).92 patients were eventually enrolled and randomly assigned to r Hu EPO group and placebo group in proportion of 1:1.A single subcutaneous injection of either 10,000 IU of r Hu EPO or equal volume of saline was given separately 24 hours before surgery.Chi-square analysis was applied to compare the occurrence of CSA-AKI.Collecting time points and differences between groups were analyzed by repeated measurement analysis of early changes in AKI biomarkers and inflammatory markers.Results: The observed incidence of CSA-AKI in the r Hu EPO group was lower than that in the control group(19.6% vs.32.5%,P=0.154),however with no statistical significance.Death and renal replacement therapy(RRT)was not observed in either group.There was no significant difference in ICU length of stay and length of hospital stay between the two groups(P>0.05).The mean values from different time points of the early biomarkers NGAL and KIM-1 tended to be lower in r Hu EPO group than those in control group,while serum NGAL differed significantly between the two groups(P=0.033).However,the inflammatory markers in the r Hu EPO group did not show a significant decrease compared with the control group.Conclusions:This study demonstrated the association between r Hu EPO administration and a lower incidence of CSA-AKI,suggesting that the use of r Hu EPO may be favorable for patients undergoing cardiac surgery with CPB.