OBJECTIVES: To investigate the effects of different filtration fractions (FFs) during continuous venovenous hemodiafiltration (CVVHDF) post-dilution. METHODS: This study employed a single-blind, head-to-head randomized controlled design. Patients who underwent daytime continuous renal replacement therapy (CRRT) in the Department of Nephrology, the Second Affiliated Hospital of Nanchang University between April 2022 and June 2023 were prospectively enrolled. They were randomly assigned to either a low FF group (FF set at 20%-<25%) or a high FF group (FF set at 25%-30%). All patients received post-dilution CVVHDF with systemic heparin anticoagulation. The primary outcome was extracorporeal circuit coagulation, comprehensively assessed through dynamic monitoring of arterial pressure, venous pressure, and transmembrane pressure, combined with filter clotting grading at the end of the session. Secondary outcomes included changes in serum creatinine, urea, potassium, and pH levels before and after treatment to evaluate efficacy. RESULTS: A total of 40 patients were included in each the low FF group and the high FF group. The baseline characteristics showed no statistically significant differences between the two groups (all P>0.05). All patients completed the treatment successfully, with a treatment duration of 10-12 hours, and no filter required replacement during the sessions. The differences in arterial pressure, venous pressure, and transmembrane pressure at 2 h, 6 h, and the end of treatment compared to values at 1 h showed no statistically significant differences between the two groups (all P>0.05). Furthermore, no significant difference was found in filter clotting grades (including Grade Ⅰ and Grade Ⅱ clotting) at the end of treatment between the two groups (all P>0.05). The creatinine clearance efficiency was significantly higher in the high FF group compared to the low FF group (P<0.01). However, no statistically significant differences were observed between the groups regarding urea reduction, or the changes in serum potassium and pH levels before and after treatment (all P>0.05). CONCLUSIONS For patients with a relatively short treatment duration of 10-12 h undergoing post-dilution CVVHDF, employing a FF of 25%-30% does not pose a higher risk of extracorporeal circuit coagulation compared to a FF of 20%-25%, but shows a trend towards higher creatinine clearance.

Objective To investigate the efficacy of N-acetylcysteine on prevention of contrast -induced nephropathy (CIN).Methods According to the regulation of evidence-based medicine,the selection criteria,elimination criteria and search strategy were defined.PubMed,Cochrane Library,Wiley Online Library and Google Scholar were searched.The literature limited range was from January 2000 to December 2011.Two investigators extracted the data independently from all the studies that accorded with selection criteria using a suitable form.All the statistical analyses were performed with RevMan version 5.1.Results A total of 151 potential literatures were screened and 16 remained literatures (including 4588 patients) were identified to accord with the criteria in this meta-analysis.In 14 literatures,the Jadad score was 3 at least.The meta-analysis of 16 trials showed N-acetylcysteine could prevent CIN from happening [odds ratio (OR)=0.65,95％ CI 0.46-0.92,P=0.01].In the groups of average Scr baseline ＜ 132.6 μmol/L,result displayed the OR of incidence associated with Nacetylcysteine for prevention of CIN was 0.93 (95％ CI 0.75-1.15,P=0.49).In the groups of average Scr baseline ≥ 132.6 μmol/L,the OR for N-acetylcysteine associated with incidence of CIN was 0.52 (95％ CI 0.30-0.93,P=0.03).Conclusion There is specific effect that N-acetylcysteine prevents CIN from happening in the groups of average Scr baseline ≥ 132.6 μmol/L.