Nattachai Srisawat

Modern Classification of Acute Kidney Injury

Acute kidney injury (AKI) is a common clinical syndrome defined as a sudden onset of reduced kidney function manifested by increased serum creatinine or a reduction in urine output. This clinical syndrome has been called by 25 different names and at least 35 definitions. As a result of this deficiency of standardized definition, reported incidences of AKI in the ICU range from 1 to 25% with mortality rates between 15 and 60%. This lack of a uniform definition not only leads to the conflicting reports in the literature but is also a major obstacle for research in the field. The recent consensus definition which was proposed by the ADQI group and expanded by AKIN has brought the RIFLE criteria and staging into position as the standard definition and diagnosis of this syndrome. The RIFLE criteria have been extensively validated in more than 550,000 patients worldwide.

Urinary Biomarkers and Renal Recovery in Critically Ill Patients with Renal Support

BACKGROUND AND OBJECTIVESnDespite significant advances in the epidemiology of acute kidney injury (AKI), prognostication remains a major clinical challenge. Unfortunately, no reliable method to predict renal recovery exists. The discovery of biomarkers to aid in clinical risk prediction for recovery after AKI would represent a significant advance over current practice.nnnDESIGN, SETTING, PARTICIPANTS, & MEASUREMENTSnWe conducted the Biological Markers of Recovery for the Kidney study as an ancillary to the Acute Renal Failure Trial Network study. Urine samples were collected on days 1, 7, and 14 from 76 patients who developed AKI and received renal replacement therapy (RRT) in the intensive care unit. We explored whether levels of urinary neutrophil gelatinase-associated lipocalin (uNGAL), urinary hepatocyte growth factor (uHGF), urinary cystatin C (uCystatin C), IL-18, neutrophil gelatinase-associated lipocalin/matrix metalloproteinase-9, and urine creatinine could predict subsequent renal recovery.nnnRESULTSnWe defined renal recovery as alive and free of dialysis at 60 days from the start of RRT. Patients who recovered had higher uCystatin C on day 1 (7.27 versus 6.60 ng/mg·creatinine) and lower uHGF on days 7 and 14 (2.97 versus 3.48 ng/mg·creatinine; 2.24 versus 3.40 ng/mg·creatinine). For predicting recovery, decreasing uNGAL and uHGF in the first 14 days was associated with greater odds of renal recovery. The most predictive model combined relative changes in biomarkers with clinical variables and resulted in an area under the receiver-operator characteristic curve of 0.94.nnnCONCLUSIONSnWe showed that a panel of urine biomarkers can augment clinical risk prediction for recovery after AKI.

Cost of acute renal replacement therapy in the intensive care unit: results from The Beginning and Ending Supportive Therapy for the Kidney (BEST Kidney) Study

IntroductionSevere acute kidney injury (AKI) can be treated with either continuous renal replacement therapy (CRRT) or intermittent renal replacement therapy (IRRT). Limited evidence from existing studies does not support an outcome advantage of one modality versus the other, and most centers around the word use both modalities according to patient needs. However, cost estimates involve multiple factors that may not be generalizable to other sites, and, to date, only single-center cost studies have been performed. The aim of this study was to estimate the cost difference between CRRT and IRRT in the intensive care unit (ICU).MethodsWe performed a post hoc analysis of a prospective observational study among 53 centers from 23 countries, from September 2000 to December 2001. We estimated costs based on staffing, as well as dialysate and replacement fluid, anticoagulation and extracorporeal circuit.ResultsWe found that the theoretic range of costs were from

Plasma neutrophil gelatinase-associated lipocalin predicts recovery from acute kidney injury following community-acquired pneumonia

3,629.80/day more with CRRT to

Acute kidney injury: definition, epidemiology, and outcome.

378.60/day more with IRRT. The median difference in cost between CRRT and IRRT was

Bactericidal Antibiotics temporarily increase inflammation and worsen acute kidney injury in experimental sepsis

289.60 (IQR 830.8-116.8) per day (greater with CRRT). Costs also varied greatly by region. Reducing replacement fluid volumes in CRRT to ≤ 25 ml/min (approximately 25 ml/kg/hr) would result in

Erythropoietin and its non‐erythropoietic derivative: Do they ameliorate renal tubulointerstitial injury in ureteral obstruction?

67.20/day (23.2%) mean savings.ConclusionsCost considerations with RRT are important and vary substantially among centers. We identified the relative impact of four cost domains (nurse staffing, fluid, anticoagulation, and extracorporeal circuit) on overall cost differences, and hospitals can look to these areas to reduce costs associated with RRT.

Effective bilirubin reduction by single-pass albumin dialysis in liver failure.

Although plasma neutrophil gelatinase-associated lipocalin (NGAL) is a promising biomarker for early detection of acute kidney injury, its ability to predict recovery is unknown. Using RIFLE criteria to define kidney injury, we tested whether higher plasma NGAL concentrations on the first day of RIFLE-F would predict failure to recover in a post hoc analysis of a multicenter, prospective, cohort study of patients with community-acquired pneumonia. Recovery was defined as alive and not requiring renal replacement therapy during hospitalization or having a persistent RIFLE-F classification at hospital discharge. Median plasma NGAL concentrations were significantly lower among the 93 of 181 patients who recovered. Plasma NGAL alone predicted failure to recover with an area under the receiver operating characteristic curve of 0.74. A clinical model using age, serum creatinine, pneumonia severity, and nonrenal organ failure predicted failure to recover with area under the curve of 0.78. Combining this clinical model with plasma NGAL concentrations did not improve prediction. The reclassification of risk of renal recovery, however, significantly improved by 17% when plasma NGAL was combined with the clinical model. Thus, in this cohort of patients with pneumonia-induced severe acute kidney injury, plasma NGAL appears to be a useful biomarker for predicting renal recovery.

Recovery from Acute Kidney Injury: Determinants and Predictors

Purpose of reviewAcute kidney injury (AKI) is a common clinical syndrome whose definition has standardized as a result of consensus by leading experts around the world. As a result of these definitions, reported AKI incidences can now be compared across different populations and settings. Evidence from population-based studies suggests that AKI is nearly as common as myocardial infarction, at least in the western world. This review aims to highlight the recent advances in AKI epidemiology as well as to suggest future directions for prevention and management. Recent findingsThis review will focus on the recent studies exploring the AKI epidemiology in and outside the ICU. In particular, the risk of AKI in less severe sepsis is notable as is evidence linking AKI to chronic kidney disease. New emphasis on renal recovery is shaping current thinking as is the use and utility of new biomarkers. SummaryThis article reviews the recent information about the definition, classification, and epidemiology of AKI. Although new biomarkers are being developed, the ‘tried and true’ markers of serum creatinine and urine output, disciplined by current criteria, will be important components in the definition and classification of AKI for some time to come.

Is there a difference between strong ion gap in healthy volunteers and intensive care unit patients

Objective: To explore the relationships among bactericidal antimicrobial treatment of sepsis, inflammatory response, severity of acute kidney injury, and outcomes. Design: Controlled laboratory experiment. Setting: University laboratory. Interventions: Sepsis was induced by cecal ligation and puncture in 52 rats and was treated with either bactericidal antibiotics (ampicillin/sulbactam) or placebo (saline). Serial blood specimens were obtained after cecal ligation and puncture for serum creatinine, interleukin-6, and neutrophil gelatinase-associated lipocalin concentrations. RIFLE (Risk, Injury, Failure, Loss, End-stage kidney disease) criteria were used to assess severity of acute kidney injury. All animals were observed for survival up to 1 wk. In a separate experiment, six healthy animals were given antibiotics and renal function was assessed. Another 12 animals were euthanized 2 days after laparotomy for kidney histology. Measurements and Main Results: Survival in the placebo group was 50% compared with 81.8% in the antibiotic group (p < .05). Most animals (93%) without antibiotics developed acute kidney injury, of which 39% exhibited greater than a threefold rise in serum creatinine (RIFLE-F). Furthermore, survival decreased as acute kidney injury severity increased. Surprisingly, all antibiotic-treated animals developed acute kidney injury, of which 68.6% reached RIFLE-F. However, renal dysfunction was less persistent in these animals. Patterns of plasma interleukin-6 were similar to creatinine with higher concentrations seen earlier in antibiotic-treated animals but with faster resolution. Interleukin-6 concentration at 24 hrs was independently associated with the development of RIFLE-F. Histologic findings were consistent with functional parameters showing that antibiotics worsened acute kidney injury. Conclusion: In polymicrobial sepsis, bactericidal antibiotics resulted in more inflammation and more severe acute kidney injury. However, resolution of inflammation and acute kidney injury was faster with antibiotics and correlated best with survival. These results suggest that transient worsening of renal function may be an expected consequence of sepsis therapy. These findings also question the value of peak severity of acute kidney injury as a primary end point and suggest that resolution of acute kidney injury may be more appropriate.