Utility of neutrophil gelatinase-associated lipocalin in the management of acute kidney injury: A prospective, observational study

Background: Utilization of renal biomarkers such as neutrophil gelatinase-associated lipocalin in the management of acute kidney injury may be useful as a diagnostic tool in the emergency department. Objective: The aim of this study is to determine the relationship between serum neutrophil gelatinase-associated lipocalin level and the severity of the acute kidney injury based on the Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease (RIFLE) classification, and to investigate the role of the serum neutrophil gelatinase-associated lipocalin level in differentiating the etiology and predicting the 30-day mortality rate and need for dialysis. Methods: This prospective, observational study was conducted from March 2015 to 2016. Adult patients with acute kidney injury in the emergency department were enrolled in the study. Demographic and clinical features such as hypovolemic state, nephrotoxic substance exposure, renal functions, and serum neutrophil gelatinase-associated lipocalin level were evaluated. After the etiology of the acute kidney injury was ascertained, the severity of the acute kidney injury was determined according to RIFLE criteria. Primary outcome was defined as the correlation between serum neutrophil gelatinase-associated lipocalin level and the severity of the acute kidney injury according to RIFLE classification. Secondary outcomes were defined as the relationship between the serum neutrophil gelatinase-associated lipocalin level and the etiology of the acute kidney injury; need for dialysis and 30-day mortality were defined as poor outcomes. Results: A total of 87 patients were included in the study. Mean serum neutrophil gelatinase-associated lipocalin levels were 380.14 ± 276.65 ng/mL in RIFLE-R, 425.80 ± 278.99 ng/mL in RIFLE-I, and 403.60 ± 293.15 ng/mL in RIFLE-F groups. There was no statistically significant relationship between the severity of acute kidney injuries and serum neutrophil gelatinase-associated lipocalin level. Initial serum neutrophil gelatinase-associated lipocalin levels in the emergency department did not indicate a statistically significant ability to predict the etiology of acute kidney injury, 30-day mortality rates, or need for dialysis. Conclusion: Initial serum neutrophil gelatinase-associated lipocalin level in the emergency department is not a determinant tool for predicting the severity, etiology, 30-day mortality rates, or need for dialysis in cases of acute kidney injuries.

Incidence and risk factors for acute kidney injury after spine surgery using the RIFLE classification

Object Earlier definitions of acute renal failure are not sensitive in identifying milder forms of acute kidney injury (AKI). The authors hypothesized that by applying the RIFLE criteria for acute renal failure (Risk of renal dysfunction, Injury to the kidney, Failure of kidney function, Loss of kidney function, and End-stage kidney disease) to thoracic and lumbar spine surgery, there would be a higher incidence of AKI. They also developed a model to predict the postoperative glomerular filtration rate (GFR). Methods A hospital data repository was used to identify patients undergoing thoracic and/or lumbar spine surgery over a 5-year period (2006–2011). The lowest GFR in the first week after surgery was used to identify and categorize kidney injury if present. Risk factors were identified and a model was developed to predict postoperative GFR based on the defined risk factors. Results A total of 726 patients were identified over the study period. The incidence of AKI was 3.9% (n = 28) based on the RIFLE classification with 23 patients in the risk category and 5 in the injury category. No patient was classified into the failure category or required renal replacement therapy. The baseline GFR in the non-AKI and AKI groups was 80 and 79.8 ml/min, respectively. After univariate analysis, only hypertension was associated with postoperative AKI (p = 0.02). A model was developed to predict the postoperative GFR. This model accounted for 64.4% of the variation in the postoperative GFRs (r2 = 0.644). Conclusions The incidence of AKI in spine surgery is higher than previously reported, with all of the patients classified into either the risk or injury RIFLE categories. Because these categories have previously been shown to be associated with poor long-term outcomes, early recognition, management, and follow-up of these patients is important.