Evaluating Early Versus Late CVVHDF Initiation in Acute Kidney Injury: A Retrospective ICU Case Study

Background: Acute Kidney Injury (AKI) is a common and life-threatening complication in critically ill patients, particularly within the Intensive Care Unit (ICU). Continuous Renal Replacement Therapy (CRRT), specifically Continuous Veno-Venous Hemodiafiltration (CVVHDF), is commonly used to manage AKI. This study aimed to evaluate the impact of early versus late initiation of CVVHDF on patient outcomes. Methods: We performed a retrospective analysis of medical records from our institution's ICU over a two-year period (2023-2024). Patients admitted for non-cardiac surgery who developed AKI and received CVVHDF were included. AKI was defined based on KDIGO criteria. We divided the patients into two groups: early initiation (48 hours of AKI diagnosis) and late initiation (>48 hours of AKI diagnosis). We also assessed the influence of high (30-35 ml/kg/h) versus standard (20-25 ml/kg/h) effluent doses. The CVVHDF protocol used heparin anticoagulation. Data collected included demographics, AKI etiology, SOFA and SAPS II scores, ICU length of stay, 28-day mortality, and laboratory parameters. Results: A total of 66 patients were included in the analysis, with a mean age of 64.18 years (66.7% male). The early CVVHDF group comprised 37 patients, while the late CVVHDF group included 29 patients. The most common etiologies of AKI were septic AKI (31.8%) and cardio-renal syndrome (19.7%). Patients in the early CVVHDF group showed better biochemical results, as evidenced by lower urea and creatinine levels at 24 hours post-initiation.There was a statistically significant trend toward lower 28-day mortality in the early CVVHDF group compared to the late group.However, subgroup analysis showed no significant difference between high and standard effluent rates.