Sofía Jorge

In May 2004, a new classification, the RIFLE (Risk, Injury, Failure, Loss of kidney function, and Endstage kidney disease) classification, was proposed in order to define and stratify the severity of acute kidney injury (AKI). This system relies on changes in the serum creatinine (SCr) or glomerular filtration rates and/or urine output, and it has been largely demonstrated that the RIFLE criteria allows the identification of a significant proportion of AKI patients hospitalized in numerous settings, enables monitoring of AKI severity, and is a good predictor of patient outcome. Three years later (March 2007), the Acute Kidney Injury Network (AKIN) classification, a modified version of the RIFLE, was released in order to increase the sensitivity and specificity of AKI diagnosis. Until now, the benefit of these modifications for clinical practice has not been clearly demonstrated.

INTRODUCTION: Whether discernible advantages in terms of sensitivity and specificity exist with Acute Kidney Injury Network (AKIN) criteria versus Risk, Injury, Failure, Loss of Kidney Function, End-stage Kidney Disease (RIFLE) criteria is currently unknown. We evaluated the incidence of acute kidney injury and compared the ability of the maximum RIFLE and of the maximum AKIN within intensive care unit hospitalization in predicting inhospital mortality of critically ill patients. METHODS: Patients admitted to the Department of Intensive Medicine of our hospital between January 2003 and December 2006 were retrospectively evaluated. Chronic kidney disease patients undergoing dialysis or renal transplant patients were excluded from the analysis. RESULTS: In total, 662 patients (mean age, 58.6 +/- 19.2 years; 392 males) were evaluated. AKIN criteria allowed the identification of more patients as having acute kidney injury (50.4% versus 43.8%, P = 0.018) and classified more patients with Stage 1 (risk in RIFLE) (21.1% versus 14.7%, P = 0.003), but no differences were observed for Stage 2 (injury in RIFLE) (10.1% versus 11%, P = 0.655) and for Stage 3 (failure in RIFLE) (19.2% versus 18.1%, P = 0.672). Mortality was significantly higher for acute kidney injury defined by any of the RIFLE criteria (41.3% versus 11%, P < 0.0001; odds ratio = 2.78, 95% confidence interval = 1.74 to 4.45, P < 0.0001) or of the AKIN criteria (39.8% versus 8.5%, P < 0.0001; odds ratio = 3.59, 95% confidence interval = 2.14 to 6.01, P < 0.0001). The area under the receiver operator characteristic curve for inhospital mortality was 0.733 for RIFLE criteria (P < 0.0001) and was 0.750 for AKIN criteria (P < 0.0001). There were no statistical differences in mortality by the acute kidney injury definition/classification criteria (P = 0.72). CONCLUSIONS: Although AKIN criteria could improve the sensitivity of the acute kidney injury diagnosis, it does not seem to improve on the ability of the RIFLE criteria in predicting inhospital mortality of critically ill patients.

Acute kidney injury (AKI) is a common complication in patients undergoing major abdominal surgery. Various recent studies using modern standardized classifications for AKI reported a variable incidence of AKI after major abdominal surgery ranging from 3 to 35%. Several patient-related, procedure-related factors and postoperative complications were identified as risk factors for AKI in this setting. AKI following major abdominal surgery has been shown to be associated with poor short- and long-term outcomes. Herein, we provide a contemporary and critical review of AKI after major abdominal surgery focusing on its incidence, risk factors, pathogeny and outcomes.

OBJECTIVES: To analyze the clinical characteristics of septic acute kidney injury (AKI) according to the Acute Kidney Injury Network (AKIN) classification, and to evaluate the capacity of this system in predicting in-hospital mortality of septic patients. METHODS: Patients with sepsis admitted to the infectious diseases intensive care unit (ICU) of our hospital between January 2004 and June 2007 were retrospectively studied. Maximum AKIN stage within the first three days of hospitalization was recorded. RESULTS: Three hundred fifteen patients were evaluated. According to AKIN criteria, 99 patients (31.4%) had AKI: 26.2% at stage 1, 20.2% at stage 2, and 53.6% at stage 3. Four patients (1.9%) with no AKI progressed to stage 1, two patients (7.7%) at stage 1 progressed to stage 2, one patient (3.8%) at stage 1 progressed to stage 3, and one patient at stage 2 (5%) progressed to stage 3. The mortality rate was 25.3% and increased significantly from normal renal function to stage 3 (normal, 12.5%; stage 1, 34.6%; stage 2, 45%; stage 3, 64.1%; p<0.0001). After adjusting for age, gender, race, pre-existing chronic kidney disease, illness severity as evaluated by acute physiology and chronic health evaluation, version II (APACHE II) score, need for mechanical ventilation, and vasopressor use, AKIN stage 1 (odds ratio (OR) 3.03, 95% confidence interval (CI) 1.12-8.19, p=0.029), stage 2 (OR 3.3, 95% CI 1.11-9.78, p=0.031), and stage 3 (OR 7.35, 95% CI 3.13-17.25, p<0.0001) predicted mortality. CONCLUSIONS: AKIN criteria are a useful tool to characterize and stratify septic patients according to the risk of death.

Sepsis-associated kidney injury is common in critically ill patients and significantly increases morbidity and mortality rates. Several complex pathophysiological factors contribute to its presentation and perpetuation, including macrocirculatory and microcirculatory changes, mitochondrial dysfunction, and metabolic reprogramming. Recovery from acute kidney injury (AKI) relies on the evolution towards adaptive mechanisms such as endothelial repair and tubular cell regeneration, while maladaptive repair increases the risk of progression to chronic kidney disease. Fundamental management strategies include early sepsis recognition and prompt treatment, through the administration of adequate antimicrobial agents, fluid resuscitation, and vasoactive agents as needed. In septic patients, organ-specific support is often required, particularly renal replacement therapy (RRT) in the setting of severe AKI, although ongoing debates persist regarding the ideal timing of initiation and dosing of RRT. A comprehensive approach integrating early recognition, targeted interventions, and close monitoring is essential to mitigate the burden of SA-AKI and improve patient outcomes in critical care settings.