Effect of plasma exchange combined with continuous renal replacement therapy on the prognosis of patients with HBV-related acute-on-chronic liver failure and acute kidney injury

Objective To investigate the effect of plasma exchange ( PE) combined with continuous renal replacement therapy ( CRRT) on the prognosis of patients with HBV-related acute-on-chronic liver failure ( ACLF) and acute kidney injury ( AKI) . Methods A retrospective analysis was performed for the clinical data of 198 HBV-ACLF-AKI patients who were admitted to The First Affiliated Hospital of Soochow University from August 1, 2013 to August 1, 2017. According to the technique of blood purification, they were divided into pharmacotherapy group ( group A with 68 patients) , PE group ( group B with 56 patients) , and PE + CRRT group ( group C with 74 patients) .Related clinical data on admission were collected, including sex, age, biochemical parameters after blood purification ( total bilirubin, albumin, serum sodium, international normalized ratio, white blood cell count, platelet count, and hematocrit) , common complications, and blood purification method. Creatinine clearance rate ( CCR) , estimated glomerular filtration rate ( eGFR) , and MELD combined with serum sodium concentration ( MELD-Na) were calculated before and after treatment. A one-way analysis of variance was used for comparison of normally distributed continuous data between three groups; the paired t-test was used for comparison within one group before and after treatment, and the two samples t-test was used for comparison between groups. The Kruskal-Wallis H test was used for comparison of non-normally distributed continuous data between three groups; the paired samples Wilcoxon signed rank test was used for comparison within one group before and after treatment, and the Mann-Whitney U test was used for comparison between groups. The chi-square test was used for comparison of categorical data between three groups. The Cox proportional-hazards regression model was used to investigate the influencing factors for survival time and outcome. Results Before treatment, there were significant differences between the three groups in sex, age, blood biochemical parameters, eGFR, CCR, complications, and MELD-Na ( all P > 0. 05) . Groups B and C had significant increases in eGFR and CCR and a significant reduction in MELD-Na after treatment ( group B: Z =-2. 81, Z =-3. 67, t = 6. 07, all P < 0. 05;group C: Z =-5. 81, Z =-4. 05, t =-6. 90, all P < 0. 05) , and there were no significant differences in eGFR, CCR, and MELD-Na between groups B and C after treatment ( all P > 0. 05) . The regression analysis showed that eGFR, CCR, and MELD-Na after blood purification were influencing factors for the survival indices of ACLF-AKI patients ( all P < 0. 05) . The risk of death and cumulative risk gradually increased over the time of hospitalization. Conclusion PE alone or in combination with CRRT can significantly improve the renal function of ACLF-AKI patients, but the combination treatment has no obvious advantages. The improvement in renal function after blood purification directly affects the prognosis of ACLF-AKI patients, and the risk of death and cumulative risk gradually increase over the time of hospitalization.