Browsing by Subject "Acute Kidney Injury"
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Item Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury(BioMed Central, 2007-03-01) Mehta, Ravindra L.; Kellum, John A.; Shah, Sudhir V.; Molitoris, Bruce A.; Ronco, Claudio; Warnock, David G.; Levin, Adeera; Medicine, School of MedicineIntroduction Acute kidney injury (AKI) is a complex disorder for which currently there is no accepted definition. Having a uniform standard for diagnosing and classifying AKI would enhance our ability to manage these patients. Future clinical and translational research in AKI will require collaborative networks of investigators drawn from various disciplines, dissemination of information via multidisciplinary joint conferences and publications, and improved translation of knowledge from pre-clinical research. We describe an initiative to develop uniform standards for defining and classifying AKI and to establish a forum for multidisciplinary interaction to improve care for patients with or at risk for AKI. Methods Members representing key societies in critical care and nephrology along with additional experts in adult and pediatric AKI participated in a two day conference in Amsterdam, The Netherlands, in September 2005 and were assigned to one of three workgroups. Each group's discussions formed the basis for draft recommendations that were later refined and improved during discussion with the larger group. Dissenting opinions were also noted. The final draft recommendations were circulated to all participants and subsequently agreed upon as the consensus recommendations for this report. Participating societies endorsed the recommendations and agreed to help disseminate the results. Results The term AKI is proposed to represent the entire spectrum of acute renal failure. Diagnostic criteria for AKI are proposed based on acute alterations in serum creatinine or urine output. A staging system for AKI which reflects quantitative changes in serum creatinine and urine output has been developed. Conclusion We describe the formation of a multidisciplinary collaborative network focused on AKI. We have proposed uniform standards for diagnosing and classifying AKI which will need to be validated in future studies. The Acute Kidney Injury Network offers a mechanism for proceeding with efforts to improve patient outcomes.Item Advances in Neonatal Acute Kidney Injury(AAP, 2021-11) Starr, Michelle C.; Charlton, Jennifer R.; Guillet, Ronnie; Reidy, Kimberly; Tipple, Trent E.; Jetton, Jennifer G.; Kent, Alison L.; Abitbol, Carolyn L.; Ambalavanan, Namasivayam; Mhanna, Maroun J.; Askenazi, David J.; Selewski, David T.; Harer, Matthew W.; Pediatrics, School of MedicineIn this state-of-the-art review, we highlight the major advances over the last 5 years in neonatal acute kidney injury (AKI). Large multicenter studies reveal that neonatal AKI is common and independently associated with increased morbidity and mortality. The natural course of neonatal AKI, along with the risk factors, mitigation strategies, and the role of AKI on short- and long-term outcomes, is becoming clearer. Specific progress has been made in identifying potential preventive strategies for AKI, such as the use of caffeine in premature neonates, theophylline in neonates with hypoxic-ischemic encephalopathy, and nephrotoxic medication monitoring programs. New evidence highlights the importance of the kidney in “crosstalk” between other organs and how AKI likely plays a critical role in other organ development and injury, such as intraventricular hemorrhage and lung disease. New technology has resulted in advancement in prevention and improvements in the current management in neonates with severe AKI. With specific continuous renal replacement therapy machines designed for neonates, this therapy is now available and is being used with increasing frequency in NICUs. Moving forward, biomarkers, such as urinary neutrophil gelatinase–associated lipocalin, and other new technologies, such as monitoring of renal tissue oxygenation and nephron counting, will likely play an increased role in identification of AKI and those most vulnerable for chronic kidney disease. Future research needs to be focused on determining the optimal follow-up strategy for neonates with a history of AKI to detect chronic kidney disease.Item Evaluating and Mitigating Risk of Acute Kidney Injury with the Combination of Vancomycin and Piperacillin-Tazobactam in Children(Springer, 2021-07) Tillman, Emma M.; Goldman, Jennifer L.; Medicine, School of MedicineThe antibiotic combination of vancomycin (VAN) and piperacillin-tazobactam (PTZ) has been associated with an increased risk of acute kidney injury (AKI) in both adult and pediatric patients. In this review, we highlight some of the limitations of existing pediatric studies evaluating the combination of VAN/PTZ, focusing on AKI risk in specific pediatric patient populations. We also review the variability in defining AKI in children and provide guidance to clinicians for use of prospective surveillance and stewardship in mitigating the risk of AKI in pediatric patients treated with combination of VAN/PTZ. Based on review of available pediatric studies, if the combination of VAN/PTZ is selected as an empirical antibiotic combination, it should be used in those at low risk for AKI and should be used with extreme caution in patients with additional nephrotoxic risks. Systems should be in place to monitor the use of VAN/PTZ and associated renal function in those receiving this antibiotic combination.Item Improving the identification of acute kidney injury in the neonatal ICU: three centers’ experiences(Nature, 2022-02) Starr, Michelle C.; Chaudhry, Paulomi; Brock, Allyson; Vincent, Katherine; Twombley, Katherine; Bonachea, Elizabeth M.; Mohamed, Tahagod H.; Pediatrics, School of MedicineOBJECTIVE: To describe three different standardized approaches to improving neonatal acute kidney injury (AKI) identification and the impact on AKI identification, incidence, and nephrology consultation and referral. STUDY DESIGN: A retrospective cohort study in three academic NICUs. We compared AKI identification, AKI incidence, nephrology consultation, and nephrology follow-up before and after implantation of local protocols to standardize neonatal AKI identification. RESULT: Neonatal AKI identification improved in all three NICUs following protocol implementation (26-85%, P < 0.0001). Each center also saw increases in nephrology consultation (15-83%, P < 0.0001) and nephrology follow-up (7-73%, P < 0.0001). AKI incidence decreased significantly (21-12%, P < 0.0001). CONCLUSION: Multiple strategies can be successfully operationalized to improve neonatal AKI identification. While different in approach, each strategy resulted in increased AKI identification and nephrology involvement. This study emphasizes the importance of local standardized approaches to AKI to improve AKI identification and nephrology involvement in the NICU.Item The macrophage mediates the renoprotective effects of endotoxin preconditioning(American Society of Nephrology (ASN), 2015-06) Hato, Takashi; Winfree, Seth; Kalakeche, Rabih; Dube, Shataakshi; Kumar, Rakesh; Yoshimoto, Momoko; Plotkin, Zoya; Dagher, Pierre C.; Department of Medicine, IU School of MedicinePreconditioning is a preventative approach, whereby minimized insults generate protection against subsequent larger exposures to the same or even different insults. In immune cells, endotoxin preconditioning downregulates the inflammatory response and yet, preserves the ability to contain infections. However, the protective mechanisms of preconditioning at the tissue level in organs such as the kidney remain poorly understood. Here, we show that endotoxin preconditioning confers renal epithelial protection in various models of sepsis in vivo. We also tested the hypothesis that this protection results from direct interactions between the preconditioning dose of endotoxin and the renal tubules. This hypothesis is on the basis of our previous findings that endotoxin toxicity to nonpreconditioned renal tubules was direct and independent of immune cells. Notably, we found that tubular protection after preconditioning has an absolute requirement for CD14-expressing myeloid cells and particularly, macrophages. Additionally, an intact macrophage CD14-TRIF signaling pathway was essential for tubular protection. The preconditioned state was characterized by increased macrophage number and trafficking within the kidney as well as clustering of macrophages around S1 proximal tubules. These macrophages exhibited increased M2 polarization and upregulation of redox and iron-handling molecules. In renal tubules, preconditioning prevented peroxisomal damage and abolished oxidative stress and injury to S2 and S3 tubules. In summary, these data suggest that macrophages are essential mediators of endotoxin preconditioning and required for renal tissue protection. Preconditioning is, therefore, an attractive model to investigate novel protective pathways for the prevention and treatment of sepsis.Item Obesity, inflammatory and thrombotic markers, and major clinical outcomes in critically ill patients with COVID‐19 in the US(Wiley, 2021-10) Friedman, Allon N.; Guirguis, John; Kapoor, Rajat; Gupta, Shruti; Leaf, David E.; Timsina, Lava R.; Medicine, School of MedicineOBJECTIVE: This study aimed to determine whether obesity is independently associated with major adverse clinical outcomes and inflammatory and thrombotic markers in critically ill patients with COVID-19. METHODS: The primary outcome was in-hospital mortality in adults with COVID-19 admitted to intensive care units across the US. Secondary outcomes were acute respiratory distress syndrome (ARDS), acute kidney injury requiring renal replacement therapy (AKI-RRT), thrombotic events, and seven blood markers of inflammation and thrombosis. Unadjusted and multivariable-adjusted models were used. RESULTS: Among the 4,908 study patients, mean (SD) age was 60.9 (14.7) years, 3,095 (62.8%) were male, and 2,552 (52.0%) had obesity. In multivariable models, BMI was not associated with mortality. Higher BMI beginning at 25 kg/m2 was associated with a greater risk of ARDS and AKI-RRT but not thrombosis. There was no clinically significant association between BMI and inflammatory or thrombotic markers. CONCLUSIONS: In critically ill patients with COVID-19, higher BMI was not associated with death or thrombotic events but was associated with a greater risk of ARDS and AKI-RRT. The lack of an association between BMI and circulating biomarkers calls into question the paradigm that obesity contributes to poor outcomes in critically ill patients with COVID-19 by upregulating systemic inflammatory and prothrombotic pathways.Item Renal endothelial dysfunction in acute kidney ischemia reperfusion injury(Bentham Science, 2014-03-01) Basile, David P.; Yoder, Mervin C.; Department of Cellular and Integrative Physiology, IU School of MedicineAcute kidney injury is associated with alterations in vascular tone that contribute to an overall reduction in GFR. Studies in animal models indicate that ischemia triggers alterations in endothelial function that contribute significantly to the overall degree and severity of a kidney injury. Putative mediators of vasoconstriction that may contribute to the initial loss of renal blood flow and GFR are highlighted. In addition, there is discussion of how intrinsic damage to the endothelium impairs homeostatic responses in vascular tone as well as promotes leukocyte adhesion and exacerbating the reduction in renal blood flow. The timing of potential therapies in animal models as they relate to the evolution of AKI, as well as the limitations of such approaches in the clinical setting are discussed. Finally, we discuss how acute kidney injury induces permanent alterations in renal vascular structure. We posit that the cause of the sustained impairment in kidney capillary density results from impaired endothelial growth responses and suggest that this limitation is a primary contributing feature underlying progression of chronic kidney disease.Item Studies on hydrodynamic delivery as a treatment for acute kidney injury(2017) Kolb, Alexander; Atkinson, Simon; Bacallao, Robert; Basile, David; Dai, Guoli; Szymanski, DanielHydrodynamic delivery is a powerful tool that allows delivery of macromolecules to the kidney culminating in gene expression. This finding is important in the fight against kidney disease. Current therapy for kidney injury, specifically acute kidney injury, is lacking. Supportive care in the form of IV fluids and medications aimed at restoring Glomerular Filtration Rate (GFR) and urine output are currently used. However, even with these treatments, prognoses of patients diagnosed with this disease remains poor. We believe that hydrodynamic delivery provides a mechanism that can be used to reverse and prevent AKI. Hydrodynamic delivery following ischemic injuries leads to reductions in serum creatinine and infiltrating mononuclear cells, as well as increased renal blood flow and survival. These changes are due to reductions in vascular congestion and inflammation typically seen following injury. To determine the underlying mechanisms of gene delivery preventing AKI, we used candidate genes identified in a proteomic screen on kidneys that recovered from AKI. We selected Isocitrate Dehydrogenase II (IDH2) and Sulfotransferase 1C2 (SULT1C2) for study and found that delivery prior to injury prevents serum creatinine increase and reduces cell death. We found that gene delivery of IDH2 prevents a glycolytic shift typically seen following ischemic injuries. The mechanism underlying the prevention of this shift are seen in increased ATP stores and spare respiratory capacity allowing the cell to remain in an oxidative state. Additionally, we show that SULT1C2 post-translationally modifies the mitochondria membrane, increasing oxidative phosphorylation providing the cell with additional energy needed in times of oxidative stress. These candidate genes allow cells to remain in an oxidative state preventing the activation of cell death pathways typically activated following injury, thereby preserving normal kidney function.Item Th-17 cell activation in response to high salt following acute kidney injury is associated with progressive fibrosis and attenuated by AT-1R antagonism(Nature Publishing Group, 2015-10) Mehrotra, Purvi; Patel, Jaymin B.; Ivancic, Carlie M.; Collett, Jason A.; Basile, David P.; Department of Cellular & Integrative Physiology, IU School of MedicineExposure of rats to elevated dietary salt following recovery from acute kidney injury (AKI) accelerates the transition to chronic kidney disease (CKD), and is dependent on lymphocyte activity. Here we tested whether high salt diet triggers lymphocyte activation in postischemic kidneys to worsen renal inflammation and fibrosis. Male Sprague-Dawley rats on a 0.4% salt diet were subjected to left unilateral ischemia-reperfusion and allowed to recover for 5 weeks. This resulted in a mild elevation of CD4(+) T cells relative to sham animals. Contralateral unilateral nephrectomy and elevated dietary salt (4%) for 4 extra weeks hastened CKD and interstitial fibrosis. Activated T cells were increased in the kidney threefold after 4 weeks of elevated dietary salt exposure relative to post-AKI rats before salt feeding. The T cell subset was largely positive for IL-17, indicative of Th-17 cells. Because angiotensin II activity may influence lymphocyte activation, injured rats were given the AT1R antagonist, losartan, along with high salt diet. This significantly reduced the number of renal Th-17 cells to levels of sham rats, and significantly reduced the salt-induced increase in fibrosis to about half. In vitro studies in AKI-primed CD4(+) T cells indicated that angiotensin II and extracellular sodium enhanced, and losartan inhibited, IL-17 expression. Thus, dietary salt modulates immune cell activity in postischemic recovering kidneys because of the activity of local RAS, suggesting the participation of these cells in CKD progression post-AKI.