Acute Kidney Injury in major abdominal surgery: improving perioperative management and minimizing risks of renal failure

The concept of acute renal failure (ARF) has undergone significant re-evaluation in recent years. Acute, relatively mild injury to the kidney or impairment of kidney function, as evidenced by changes in urine output and blood chemistries, can lead to serious clinical consequences [8]. Traditionally, severe reduction in kidney function is associated with severe azotemia and oliguria/anuria; however, recent findings have recognized that even moderate decreases in kidney function can be critically important in the critically ill patients. Small changes in kidney function in hospitalized patients are associated with significant alterations in short and long-term outcomes. The RIFLE/AKIN criteria provide a standardized definition of AKI and have become the benchmark for diagnostic criteria. The severity grades of AKI represent patient groups with increasing illness severity, as illustrated by a higher proportion of patients requiring renal replacement therapy and increased mortality rates. Regarding ASA-AKI, the proposed study project was partially implemented. In terms of data analysis, rather than comparing the two patient groups, it proved more beneficial to analyse perioperative and resuscitation management across the entire patient population. Since 2018, there has been a widespread adherence to KDIGO guidelines for managing AKI patients in all aspects, from identifying at-risk patients in the preoperative phase to the modalities of CRRT. ICU treatment has addressed all relevant aspects: minimizing the use of nephrotoxic drugs, managing fluid therapy and hydro electrolyte balance, administering vasoactive drugs, and conducting invasive hemodynamic monitoring, antibiotic therapy and nutritional support. However, some limitations of the study regarding CRRT management have been identified. Specifically, starting in 2021, a dedicated table for filter lifespan was not introduced as initially planned, which would have allowed for recording issues that arose and the reasons for filter cessation. Medical staff was expected to document in the clinical diary the exact time (day, hour) when the filter fails and the reason for this. Regarding preoperative fasting has been reduced since the implementation of ERAS protocols (May 20, 2022, Careggi), but further improvements are needed to decrease fasting hours or increase fluid administration or oral intake for patients at higher risk of ASA-AKI, particularly those coming from the emergency department. Other than Cystatin-C, no other biomarkers have been utilized for the early detection of AKI. Despite significant efforts to recognize, classify, stratify risk, and treat patients with AKI to improve outcomes in this population, these measures may not be sufficient. Indeed, despite extensive work, there remains a lack of homogeneity in the ICU management of AKI patients, highlighting the complexity of this condition.