Acute kidney injury

Investigations into ferroptosis in methylmercury-induced acute kidney injury in mice

Methylmercury (MeHg) is a highly poisonous form of mercury and a risk factor for kidney impairment in humans that currently has no effective means of therapy. Ferroptosis is a non-apoptotic metabolic cell death linked to numerous diseases. It is currently unknown whether ferroptosis takes part in MeHg-induced kidney damage. Here, we established a model of acute kidney injury (AKI) in mice by gavage with different doses of MeHg (0, 40, 80, 160 μmol/kg). Serological analysis revealed elevated levels of UA, UREA, and CREA; H&E staining showed variable degrees of renal tubule injury; qRT-PCR detection displayed increased expression of KIM-1 and NGAL in the groups with MeHg treatment, indicated that MeHg successfully induced AKI. Furthermore, MDA levels enhanced in renal tissues of mice with MeHg exposure whereas GSH levels decreased; ACSL4 and PTGS2 nucleic acid levels elevated while SLC7A11 levels reduced; transmission electron microscopy illustrated that the density of the mitochondrial membrane thickened and the ridge reduced considerably; protein levels for 4HNE and TfR1 improved since GPX4 levels declined, all these results implying the involvement of ferroptosis as a result of MeHg exposure. Additionally, the observed elevation in the protein levels of NLRP3, p-p65, p-p38, p-ERK1/2, and KEAP1 in tandem with downregulated Nrf2 expression levels indicate the involvement of the NF-κB/NLRP3/MAPK/Nrf2 pathways. All the above findings suggested that ferroptosis and the NF-κB/NLRP3/MAPK/Nrf2 pathways are implicated in MeHg-induced AKI, thereby providing a theoretical foundation and reference for future investigations into the prevention and treatment of MeHg-induced kidney injury.

Acute kidney injury and renal replacement therapy: terminology standardization

The Department of Acute Kidney Injury (IRA) of the Brazilian Society of Nephrology prepared this document for the purpose of standardizing AKI terminology and dialysis modalities in the Portuguese language for Brazil. Several terms with similar meanings have been used in AKI and its dialysis modalities, causing confusion and disparities among patients, nephrologists, health institutions, private care companies, insurance companies and government entities. These disparities can impact medical care, hospital organization and care, as well as the funding and reimbursement of AKI-related procedures. Thus, consensual nomenclature and definitions were developed, including the definitions of AKI, acute kidney disease (AKD) and chronic kidney disease (CKD). Additionally, we addressed all dialysis modalities and extracorporeal procedures related to AKI, currently approved and available in the country. The Brazilian Society of Nephrology hopes that this Consensus can standardize the terminology and provide technical support to all involved in AKI care in Brazil.

Injúria renal aguda e métodos de suporte: padronização da nomenclatura

Resumo O Departamento de Injúria Renal Aguda (IRA) da Sociedade Brasileira de Nefrologia elaborou o presente documento para fins de padronização da terminologia em IRA e modalidades dialíticas na língua portuguesa para o Brasil. Diversos termos com significados semelhantes têm sido empregados em IRA e suas modalidades dialíticas, causando confusão e disparidades entre pacientes, nefrologistas, instituições de saúde, empresas privadas de assistência, seguradoras e entidades governamentais. Essas disparidades podem impactar a assistência médica, a organização e o atendimento hospitalares, assim como o financiamento e reembolso dos procedimentos relacionados com a IRA. Assim, nomenclatura e definições consensuais foram elaboradas, incluindo-se as definições de IRA, doença renal aguda (DRA) e doença renal crônica (DRC). Adicionalmente, todas as modalidades dialíticas e os procedimentos extracorpóreos relacionados a IRA, atualmente aprovados e disponíveis no país, foram abordados. A Sociedade Brasileira de Nefrologia espera que este Consenso possa padronizar a nomenclatura e prover suporte técnico para todos os atores envolvidos na assistência à IRA no Brasil.

Continuous renal replacement therapy and extended indications

Extracorporeal blood purification (EBP) techniques provide support for critically ill patients with single or multiple organ dysfunction. Continuous renal replacement therapy (CRRT) is the modality of choice for kidney support for those patients and orchestrates the interactions between the different artificial organ support systems. Intensive care teams should be familiar with the concept of sequential extracorporeal therapy and plan on how to incorporate new treatment modalities into their daily practices. Importantly, scientific evidence should guide the decision-making process at the bedside and provide robust arguments to justify the costs of implementing new EBP treatments. In this narrative review, we explore the extended indications for CRRT as an adjunctive treatment to provide support for the heart, lung, liver, and immune system. We detail practicalities on how to run the treatments and how to tackle the most frequent complications regarding each of the therapies, whether applied alone or integrated. The physicochemical processes and technologies involved at the molecular level encompassing the interactions between the molecules, membranes, and resins are spotlighted. A clinical case will illustrate the timing for the initiation, maintenance, and discontinuation of EBP techniques.

Association Between Furosemide Exposure and Clinical Outcomes in a Retrospective Cohort of Critically Ill Children

Furosemide is commonly prescribed in critically ill patients to increase the urine output and prevent fluid overload (FO) and acute kidney injury (AKI), but not supported by conclusive evidence. There remain conflicting findings on whether furosemide associates with AKI and adverse outcomes. Information on the impact of furosemide on adverse outcomes in a general population of pediatric intensive care unit (PICU) is limited. The aim of the cohort study was to investigate the associations of furosemide with AKI and clinical outcomes in critically ill children. Study Design: We retrospectively reviewed a cohort of 456 critically ill children consecutively admitted to PICU from January to December 2016. The exposure of interest was the use of furosemide in the first week after admission. FO was defined as ≥5% of daily fluid accumulation, and mean FO was considered significant when mean daily fluid accumulation during the first week was ≥5%. The primary outcomes were AKI in the first week after admission and mortality during PICU stay. AKI diagnosis was based on Kidney Disease: Improving Global Outcomes criteria with both serum creatinine and urine output. Results: Furosemide exposure occurred in 43.4% of all patients (n = 456) and 49.3% of those who developed FO (n = 150) in the first week after admission. Patients who were exposed to furosemide had significantly less degree of mean daily fluid accumulation than those who were not (1.10 [-0.33 to 2.61%] vs. 2.00 [0.54-3.70%], P < 0.001). There was no difference in the occurrence of AKI between patients who did and did not receive furosemide (22 of 198 [11.1%] vs. 36 of 258 [14.0%], P = 0.397). The mortality rate was 15.4% (70 of 456), and death occurred more frequently among patients who received furosemide than among those who did not (21.7 vs. 10.5%, P = 0.002). Furosemide exposure was associated with increased odds for mortality in a multivariate logistic regression model adjusted for body weight, gender, illness severity assessed by PRISM III score, the presence of mean FO, and AKI stage [adjusted odds ratio (AOR) 1.95; 95%CI, 1.08-3.52; P = 0.026]. Conclusion: Exposure to furosemide might be associated with increased risk for mortality, but not AKI, in critically ill children.