Kinetic changes in serum procalcitonin predict persistent acute kidney injury in critical patients.

PURPOSE: Persistent acute kidney injury (AKI) has been shown to be closely associated with poor prognosis in critical patients. Recent studies have shown that procalcitonin (PCT) is valuable for the early prediction of AKI in critically patients. Our aim was to determine whether PCT and its kinetic changes could predict the occurrence of persistent AKI in critical patients. METHODS: This is a prospective observational study. The definition of AKI was based on the Kidney Disease: Improving Global Outcomes criteria. Persistent AKI was defined as renal function that does not return to baseline serum creatinine levels within 48 h. Blood samples were obtained at the onset of AKI and two subsequent days of hospital stay. 24-h PCT change (ΔPCT-24 h) was defined as 24 h PCT minus baseline PCT (day 0). RESULTS: A total of 91 critical patients with AKI were included in this study. The persistent AKI group had a stepwise increase in PCT concentration. ΔPCT-24 h was higher in the persistent AKI group (p < .01). Logistic regression analysis showed that ΔPCT-24 h (p = .04) was independent predictors of persistent AKI. The receiver operating characteristic curves showed that area under the curve of ΔPCT-24 h was 0.84 (p < .01), and the cut-off value for PCT to predict persistent AKI was 0.56 ng/ml. CONCLUSION: Our study showed that the observation of kinetic changes in PCT is more significant for the early prediction of persistent AKI than the index of PCT at a single time point. ΔPCT-24 h is a good predictor of persistent AKI in critical patients.

Fractional excretion of sodium and potassium and urinary strong ion difference in the evaluation of persistent AKI in sepsis.

OBJECTIVE: To evaluate the diagnostic performance of FENa (Fractional excretion of sodium), FEK (fractional excretion of potassium) and uSID (urinary strong ion difference) in predicting pAKI in sepsis and septic shock. DESIGN: Retrospective cohort study. SETTING: Two intensive care units in Argentina. PATIENTS: Adult patients with a confirmed diagnosis of sepsis or septic shock and AKI, and had a urinary biochemistry within 24h of the AKI diagnosis. INTERVENTIONS: None. MAIN VARIABLES OF INTEREST: We evaluated the diagnostic accuracy of FENa, FEK and uSID through a ROC (Receiver Operating Characteristic) curve analysis. RESULTS: 80 patients were included. 40 patients presented pAKI. pAKI group had higher APACHE, SOFA score, and mortality rate. In the ROC curve analysis, uSID had no diagnostic utility (AUC=0.52, p=0.69). FENa presented moderate accuracy showing an AUC of 0.71 (95% CI 0.60-0.83; p=0.001), while FEK presented low accuracy with an AUC of 0.69 (95% CI 0.57-0.80; p=0.04). The optimal Youden point for identifying pAKI was at a FENa higher than 0.51 % with a specificity of 72.5% and a sensitivity of 65.0%. In the case of FEK, a value higher than 21.9 % presented the best relation, with a specificity of 67.5% and a sensitivity of 65.0%. CONCLUSIONS: urine biochemistry interpretation in septic patients must be revised. FENa and FEK are related to the severity of AKI and could be helpful complementary tools for diagnosing pAKI.

Transient and persistent acute kidney injury in acute liver failure.

BACKGROUND: Acute Kidney Injury (AKI) is a very frequent complication in the Acute Liver Failure (ALF) population associated with negative outcomes. We aim to evaluate the impact of AKI duration on the outcomes of an ALF population. METHODS: A 20-year retrospective analysis of ALF patients admitted to an Intensive Care Unit (ICU) was performed. Chronic liver failure, chronic kidney disease on renal replacement therapy, dialysis requirement within the week prior or an ICU stay of less than 48 h after AKI diagnosis, were exclusion criteria. AKI was defined according to the KDIGO criteria and classified into transient (< 48 h duration) or persistent (48 h duration). RESULTS: A total of 51 patients were included in the analysis and most had AKI (66.7%). Persistent AKI patients (70.6%) presented more frequently with AKI at admission and a higher SOFA score than transient AKI and no AKI, p < 0.05. More severe AKI, sepsis, vasopressor support and mechanical ventilation were also more common (p < 0.05). Nineteen (55.9%) were classified as persistent AKI exclusively by serum creatinine and 15 (44.1%) by both serum creatinine and urine output criteria. Mean survival time at 30 days was 11.3 days for persistent AKI, 25.3 days for transient AKI and 27.0 days for no AKI, p = 0.01. Adjusted multivariate cox regression analysis showed that persistent AKI predicted in-hospital mortality but it lost significance when AKI severity was introduced in the model. CONCLUSION: Persistent AKI was common in ALF patients and associated with more severe AKI, worst systemic complications and a higher 30-day mortality, compared to transient and no AKI patients.