Acute kidney injury in nonagenarians: clinical characteristics and mortality / Injúria renal aguda em nonagenários: características clínicas e mortalidade

Abstract Introduction: Nonagenarians constitute a rising percentage of inpatients, with acute kidney injury (AKI) being frequent in this population. Thus, it is important to analyze the clinical characteristics of this demographic and their impact on mortality. Methods: Retrospective study of nonagenarian patients with AKI at a tertiary hospital between 2013 and 2022. Only the latest hospital admission was considered, and patients with incomplete data were excluded. A logistic regression analysis was conducted to define risk factors for mortality. A p-value < 0.05 was considered statistically significant. Results: A total of 150 patients were included, with a median age of 93.0 years (91.2-95.0), and males accounting for 42.7% of the sample. Sepsis was the most common cause of AKI (53.3%), followed by dehydration/hypovolemia (17.7%), and heart failure (17.7%). ICU admission occurred in 39.3% of patients, mechanical ventilation in 14.7%, vasopressors use in 22.7% and renal replacement therapy (RRT) in 6.7%. Death occurred in 56.7% of patients. Dehydration/hypovolemia as an etiology of AKI was associated with a lower risk of mortality (OR 0.18; 95% CI 0.04-0.77, p = 0.020). KDIGO stage 3 (OR 3.15; 95% CI 1.17-8.47, p = 0.023), ICU admission (OR 12.27; 95% CI 3.03-49.74, p < 0.001), and oliguria (OR 5.77; 95% CI 1.98-16.85, p = 0.001) were associated with mortality. Conclusion: AKI nonagenarians had a high mortality rate, with AKI KDIGO stage 3, oliguria, and ICU admission being associated with death.

Resumo Introdução: Nonagenários constituem um percentual de pacientes internados em ascensão, sendo a injúria renal aguda (IRA) frequente nesses pacientes. Sendo assim, é importante analisar as características clínicas dessa população e seu impacto na mortalidade. Métodos: Estudo retrospectivo de pacientes nonagenários com IRA entre 2013 e 2022 em um hospital terciário. Apenas o último internamento foi considerado e pacientes com dados incompletos foram excluídos. Uma análise por regressão logística foi realizada para definir fatores de risco para mortalidade. Um valor de p < 0,05 foi considerado significativo. Resultados: Foram incluídos 150 pacientes com mediana de idade 93,0 anos (91,2-95,0) e sexo masculino em 42,7%. Sepse foi a causa mais comum de IRA (53,3%), seguida de desidratação/hipovolemia (17,7%) e insuficiência cardíaca (17,7%). Admissão na UTI ocorreu em 39,3% dos pacientes, ventilação mecânica em 14,7%, uso de vasopressores em 22,7% e realização de terapia renal substitutiva (TRS) em 6,7%. Óbito ocorreu em 56,7% dos pacientes. Desidratação/hipovolemia como etiologia da IRA foi associado a menor risco de mortalidade (OR 0,18; IC 95% 0,04-0,77, p = 0,020). Estágio KDIGO 3 (OR 3,15; IC 95% 1,17-8,47, p = 0,023), admissão na UTI (OR 12,27; IC 95% 3,03-49,74, p < 0,001) e oligúria (OR 5,77; IC 95% 1,98-16,85, p = 0,001) foram associados à mortalidade. Conclusão: Nonagenários com IRA apresentaram alta mortalidade e IRA KDIGO 3, oligúria e admissão na UTI foram associadas ao óbito.

Acute kidney injury in nonagenarians: clinical characteristics and mortality.

INTRODUCTION: Nonagenarians constitute a rising percentage of inpatients, with acute kidney injury (AKI) being frequent in this population. Thus, it is important to analyze the clinical characteristics of this demographic and their impact on mortality. METHODS: Retrospective study of nonagenarian patients with AKI at a tertiary hospital between 2013 and 2022. Only the latest hospital admission was considered, and patients with incomplete data were excluded. A logistic regression analysis was conducted to define risk factors for mortality. A p-value < 0.05 was considered statistically significant. RESULTS: A total of 150 patients were included, with a median age of 93.0 years (91.2-95.0), and males accounting for 42.7% of the sample. Sepsis was the most common cause of AKI (53.3%), followed by dehydration/hypovolemia (17.7%), and heart failure (17.7%). ICU admission occurred in 39.3% of patients, mechanical ventilation in 14.7%, vasopressors use in 22.7% and renal replacement therapy (RRT) in 6.7%. Death occurred in 56.7% of patients. Dehydration/hypovolemia as an etiology of AKI was associated with a lower risk of mortality (OR 0.18; 95% CI 0.04-0.77, p = 0.020). KDIGO stage 3 (OR 3.15; 95% CI 1.17-8.47, p = 0.023), ICU admission (OR 12.27; 95% CI 3.03-49.74, p < 0.001), and oliguria (OR 5.77; 95% CI 1.98-16.85, p = 0.001) were associated with mortality. CONCLUSION: AKI nonagenarians had a high mortality rate, with AKI KDIGO stage 3, oliguria, and ICU admission being associated with death.

Reduction of estimated glomerular filtration rate after COVID-19-associated acute kidney injury / Redução da taxa de filtração glomerular estimada após injúria renal aguda associada à COVID-19

ABSTRACT Introduction: Acute Kidney Injury (AKI), a frequent manifestation in COVID-19, can compromise kidney function in the long term. We evaluated renal function after hospital discharge of patients who developed AKI associated with COVID-19. Methods: This is an ambidirectional cohort. eGFR and microalbuminuria were reassessed after hospital discharge (T1) in patients who developed AKI due to COVID-19, comparing the values with hospitalization data (T0). P < 0.05 was considered statistically significant. Results: After an average of 16.3 ± 3.5 months, 20 patients were reassessed. There was a median reduction of 11.5 (IQR: -21; -2.1) mL/min/1.73m2 per year in eGFR. Forty-five percent of patients had CKD at T1, were older, and had been hospitalized longer; this correlated negatively with eGFR at T1. Microalbuminuria was positively correlated with CRP at T0 and with a drop in eGFR, as well as eGFR at admission with eGFR at T1. Conclusion: There was a significant reduction in eGFR after AKI due to COVID-19, being associated with age, length of hospital stay, CRP, and need for hemodialysis.

RESUMO Introdução: A Injúria Renal Aguda (IRA), uma manifestação frequente na COVID-19, pode comprometer a função renal em longo prazo. Avaliamos a função renal após a alta hospitalar de pacientes que desenvolveram IRA associada à COVID-19. Métodos: Esta é uma coorte ambidirecional. A TFGe e a microalbuminúria foram reavaliadas após a alta hospitalar (T1) em pacientes que desenvolveram IRA devido à COVID-19, comparando os valores com dados de hospitalização (T0). P < 0,05 foi considerado estatisticamente significativo. Resultados: Após uma média de 16,3 ± 3,5 meses, 20 pacientes foram reavaliados. Houve uma redução média de 11,5 (IIQ: -21; -2,1) mL/min/1,73m2 por ano na TFGe. Quarenta e cinco por cento dos pacientes apresentaram DRC no T1, eram mais velhos e haviam sido hospitalizados por mais tempo; isso se correlacionou negativamente com a TFGe no T1. A microalbuminúria foi positivamente correlacionada com a PCR no T0 e com uma queda na TFGe, assim como a TFGe na admissão com a TFGe no T1. Conclusão: Houve uma redução significativa na TFGe após IRA devido à COVID-19, sendo associada à idade, tempo de internação, PCR e necessidade de hemodiálise.

Reduction of estimated glomerular filtration rate after COVID-19-associated acute kidney injury.

INTRODUCTION: Acute Kidney Injury (AKI), a frequent manifestation in COVID-19, can compromise kidney function in the long term. We evaluated renal function after hospital discharge of patients who developed AKI associated with COVID-19. METHODS: This is an ambidirectional cohort. eGFR and microalbuminuria were reassessed after hospital discharge (T1) in patients who developed AKI due to COVID-19, comparing the values with hospitalization data (T0). P < 0.05 was considered statistically significant. RESULTS: After an average of 16.3 ± 3.5 months, 20 patients were reassessed. There was a median reduction of 11.5 (IQR: -21; -2.1) mL/min/1.73m2 per year in eGFR. Forty-five percent of patients had CKD at T1, were older, and had been hospitalized longer; this correlated negatively with eGFR at T1. Microalbuminuria was positively correlated with CRP at T0 and with a drop in eGFR, as well as eGFR at admission with eGFR at T1. CONCLUSION: There was a significant reduction in eGFR after AKI due to COVID-19, being associated with age, length of hospital stay, CRP, and need for hemodialysis.

Influência da modalidade dialítica na cognição: uma revisão integrativa / Influence of the dialysis modality in cognition: an integrative review

A doença renal crônica é uma condição clínica caracterizada pela queda progressiva da função renal, interferindo na homeostase de todo o corpo, incluindo o sistema nervoso central. Nesses pacientes, o comprometimento cognitivo é um achado comum, em comparação com a população geral, e mais frequente nos pacientes em diálise. O objetivo deste estudo foi identificar, por meio de revisão integrativa, se há diferença entre a modalida- de dialítica (hemodiálise e diálise peritoneal) e a presença de comprometimento cognitivo nesses pacientes. Foi feito levan- tamento bibliográfico nas plataformas PubMed® e Bireme, com buscas padronizadas de 2014 até abril de 2019, utilizando-se pa- lavras-chave. Para a seleção e a avaliação dos estudos científicos levantados, foram estabelecidos critérios, contemplando os seguintes aspectos: autor, ano/local, grau de recomendação/ nível de evidência científica, amostra, faixa etária, média de idade em anos, métodos de avaliação, resultados e conclusão. Dos 561 artigos encontrados, 365 foram excluídos pela data de publicação, 87 foram excluídos pelo título, 17 pelo resumo, 49 pela leitura do artigo, 36 eram repetidos e oito foram selecio- nados para o estudo. Os pacientes em diálise peritoneal apre- sentaram menor comprometimento cognitivo e menor risco para demência que os pacientes em hemodiálise.

Chronic kidney disease is a clinical condition characterized by progressive decline in renal function, interfering with whole-bo- dy homeostasis, including the central nervous system. Cognitive impairment is a common finding in these patients, compared to the general population, besides being more frequent in dialysis patients. The objective of this study was to identify, through an integrative review, if there is difference between the dialysis mo- dality (hemodialysis and peritoneal dialysis) and the presence of cognitive impairment in these patients. A bibliographic search on the PubMed® and Bireme platforms, with standard searches from 2014 to April 2019, using keywords, was conducted. For the selection and evaluation of scientific studies found in the sear- ch, criteria have been established, considering the following as- pects: author, year/location, grade of recommendation/level of evidence, sample, age, mean age in years, evaluation methods, results, and conclusion. Among 561 articles found, 365 were ex- cluded based on the date of publication, 87 based on the title, 17 on the abstract, 48 on the article reading, 36 were repeated, and eight were selected for the study. Patients on peritoneal dialysis have less cognitive impairment and lower risk for dementia than patients on hemodialysis.

Kidney biomarkers in tropical infections: an update.

Neglected tropical diseases affect over 1 billion people, and cause 170,000 deaths each year. They result in disability, stigma and disfigurement, and also push families into poverty. Tropical infections can involve the kidney, presenting as a wide variety of ways, varying from transient urinary abnormalities to severe acute kidney injury (AKI). It is important to assess renal function in patients with tropical infections for earlier detection of AKI, appropriate treatment and prevention of Chronic Kidney Disease (CKD) outcome in some of them. There was an exponential increase in research on new kidney biomarkers that were earlier and specific for renal damage but few in the scope of tropical infections. In this review, we focus on kidney biomarkers that are being studied in some of the most prevalent tropical infections such as visceral leishmaniasis, leptospirosis, malaria, schistosomiasis and leprosy. Further studies are needed to evaluate the usefulness of renal biomarkers in the early diagnosis of renal diseases associated with tropical infections.

Aquaporin-2 and NKCC2 expression pattern in patients with hepatosplenic schistosomiasis.

OBJECTIVE: Schistosoma mansoni infection is considered a public health problem. Glomerular involvement in schistosomiasis is a well-documented complication, especially in hepatosplenic schistosomiasis (HSS). However, renal tubular function is poorly understood. The aim of this study was to investigate, through urinary exosomes, tubular transporters functionally in HSS patients. METHODS: Cross-sectional study of 20 HSS patients who had isolated exosomes from urine samples. Protease inhibitor was added in the urine samples who were immediately frozen at -80 °C for further exosomes isolation. After urine had thawed, urinary exosomes were obtained using extensive vortexing, centrifugation and ultracentrifugation steps of urine. Urinary transporters expression from exosomes was evaluated by western blot, including NHE3, AQP2 and NKCC2. Charge amounts for gel electrophoresis were adjusted by urinary creatinine concentration of each patient to avoid urinary concentration bias. All protein expression of HSS patients was relative to healthy controls. RESULTS: The expression of aquaporin-2 (AQP2) was lower in HSS patients than in controls (46.8 ± 40.7 vs. 100 ± 70.2%, P = 0.03) and the expression of the NKCC2 co-transporter was higher (191.7 ± 248.6 vs. 100 ± 43.6%, P = 0.02). CONCLUSIONS: The decrease of AQP2 and the increase of NKCC2 expression in HSS patients seem to be involved with the inability of urinary concentration in these patients. These data show renal tubular abnormalities in HSS patients without manifest clinical disease.

OBJECTIF: L'infection à Schistosoma mansoni est considérée comme un problème de santé publique. L'atteinte glomérulaire dans la schistosomiase est une complication bien documentée, en particulier dans la schistosomiase hépatosplénique (SH). Cependant, la fonction tubulaire rénale est mal connue. Le but de cette étude était d'étudier, par le biais d'exosomes urinaires, les transporteurs tubulaires fonctionnellement chez les patients atteints de SH. MÉTHODES: Il s'agit d'une étude transversale sur 20 patients atteints de SH qui avaient des exosomes isolés d'échantillons d'urine. Un inhibiteur de protéase a été ajouté dans les échantillons d'urine qui ont été immédiatement congelés à -80°C pour un isolement supplémentaire des exosomes. Après décongélation de l'urine, des exosomes urinaires ont été obtenus en utilisant des étapes étendues de vortex, de centrifugation et d'ultracentrifugation d'urine. L'expression des transporteurs urinaires d'exosomes a été évaluée par western blot, y compris NHE3, AQP2 et NKCC2. Les quantités de charge pour l'électrophorèse sur gel ont été ajustées par la concentration de créatinine urinaire de chaque patient pour éviter un biais de concentration urinaire. Toute expression protéique des patients atteints de SH était relative à celle de témoins sains. RÉSULTATS: L'expression de l'aquaporine-2 (AQP2) était plus faible chez les patients SH que chez les témoins (46,8 ± 40,7 vs 100 ± 70,2%, P = 0,03) et l'expression du co-transporteur NKCC2 était plus élevée (191,7 ± 248,6 vs 100 ± 43,6%, P = 0,16). CONCLUSIONS: La diminution de l'AQP2 et l'augmentation de l'expression de NKCC2 chez les patients SH semblent être impliquées dans l'incapacité de concentration urinaire chez ces patients. Ces données montrent des anomalies tubulaires rénales chez les patients SH sans maladie clinique manifeste.

Acute kidney injury in schistosomiasis: a retrospective cohort of 60 patients in Brazil.

The aim of this study is to investigate renal involvement in schistosomiasis. This is a retrospective cohort of 60 consecutive patients with schistosomiasis admitted to a university hospital in Maceió, Brazil. The patients were divided into 2 groups: patients with and without acute kidney injury (AKI) according to the RIFLE criteria. We compared the groups for differences in clinical manifestations and laboratory tests. Patients' mean age was 58 ± 16 yr, and 56.7% were female. The average length of hospital stay was 16.4 ± 12.1 days. Patients with hypertension and diabetes were 35% and 21.7% respectively. The main clinical symptoms and signs presented were ascites (86.7%), splenomegaly (80%), and hepatomegaly (63.3%). Current or previous history of upper gastrointestinal bleeding was found in 45% of patients, esophageal varices on endoscopy were present in 92%, and periportal fibrosis on ultrasound examination in 81% of patients. AKI incidence was 43.3% during hospital stay. Mean age and length of hospitalization were higher in the AKI group. Diuretic use, such as furosemide and spironolactone, ascites, and AST levels were also associated with AKI. Death occurred in 5 cases (8.5%), 4 of them in the AKI group. The classifications Child-Pugh score (CHILD) and Model for End-Stage Liver Disease (MELD), used to assess the severity and prognosis of chronic liver disease, presented higher scores among patients with AKI (CHILD: 9.5 ± 1.5 vs. 8.4 ± 1.7, P = 0.02; MELD: 19 ± 5.8 vs. 13 ± 3.9, P < 0.001). Renal dysfunction is an important feature of schistosomiasis, which is associated with significant morbidity and possible increased mortality. Further studies are necessary to establish the mechanisms through which schistosomiasis can lead to renal dysfunction.

Renal function in hepatosplenic schistosomiasis--an assessment of renal tubular disorders.

BACKGROUND: Renal involvement in Schistosoma mansoni infection is not well studied. The aim of this study is to investigate the occurrence of renal abnormalities in patients with hepatosplenic schistosomiasis (HSS), especially renal tubular disorders. METHODS: This is a cross-sectional study with 20 consecutive patients with HSS followed in a medical center in Maceió, Alagoas, Brazil. Urinary acidification and concentration tests were performed using calcium chloride (CaCl2) after a 12-h period of water and food deprivation. The biomarker monocyte chemoattractant protein 1 (MCP-1) was quantified in urine. Fractional excretion of sodium (FENa+), transtubular potassium gradient (TTKG) and solute-free water reabsorption (TcH2O) were calculated. The HSS group was compared to a group of 17 healthy volunteers. RESULTS: Patients' mean age and gender were similar to controls. Urinary acidification deficit was found in 45% of HSS patients. Urinary osmolality was significantly lower in HSS patients (588 ± 112 vs. 764 ± 165 mOsm/kg, p = 0,001) after a 12-h period of water deprivation. TcH2O was lower in HSS patients (0.72 ± 0.5 vs. 1.1 ± 0.3, p = 0.04). Urinary concentration deficit was found in 85% of HSS patients. The values of MCP-1 were higher in HSS group than in control group (122 ± 134 vs. 40 ± 28 pg/mg-Cr, p = 0.01) and positively correlated with the values of microalbuminuria and proteinuria. CONCLUSIONS: HSS is associated with important kidney dysfunction. The main abnormalities found were urinary concentrating ability and incomplete distal acidification defect, demonstrating the occurrence of tubular dysfunction. There was also an increase in urinary MCP-1, which appears to be a more sensitive marker of renal damage than urinary albumin excretion rate.

Índice tornozelo-braço em pacientes hemodialíticos / Ankle-brachial index in hemodialysis patients

INTRODUÇÃO: Apesar da elevada mortalidade dos pacientes em hemodiálise devido às doenças cardiovasculares, é incomum a realização de exames diagnósticos para doença arterial obstrutiva periférica e artérias pouco compressíveis. OBJETIVOS: Analisar a prevalência de doença arterial obstrutiva periférica e artérias pouco compressíveis em hemodialisados, comparando-os com o Grupo Controle. MÉTODOS: Tratou-se de um estudo transversal, com 78 hemodialisados e 88 pacientes que não faziam hemodiálise com, pelo menos, dois fatores de risco para doença arterial obstrutiva periférica (Grupo Controle). Para aferição da pressão arterial sistólica, utilizou-se Doppler vascular portátil e esfigmomanômetro. Esta foi aferida somente nos membros que não possuíam fístula arteriovenosa. O índice tornozelo-braço foi calculado utilizando cada artéria do membro inferior. Foram considerados normais os valores de 0,9 a 1,3. RESULTADOS: Diagnosticou-se doença arterial obstrutiva periférica e artérias pouco compressíveis em 26,9 e 30,8%, dos hemodialisados, e em 33 e 22,7%, do Grupo Controle. Nos hemodialisados, verificou-se o índice tornozelo-braço alterado em 75% dos sintomáticos (p=0,005), em 67,3% dos homens e 31% das mulheres (p<0,005), em 78,6% dos idosos, 34,8% dos adultos jovens (p<0,01) e em 76,9% dos diabéticos (p<0,005 versus não diabéticos). Esses pacientes apresentaram maior prevalência de doença arterial obstrutiva periférica grave do que o Grupo Controle (p<0,01). CONCLUSÕES: O índice tornozelo-braço anormal foi muito prevalente nos grupos estudados; entretanto, os hemodialisados apresentaram alterações mais graves quando comparados ao Grupo Controle. Diabetes melito, sexo masculino e idade avançada foram fatores de risco importantes para a alteração do índice tornozelo-braço nos hemodialisados. O índice tornozelo-braço foi um bom método de rastreio para alterações pesquisadas. Portanto, a utilização deste na rotina de manejo de pacientes em hemodiálise é sugerida.

INTRODUCTION: Despite the high mortality in hemodialysis patients due to cardiovascular diseases, it is unusual performing diagnostic tests for peripheral arterial disease and poorly compressible arteries. OBJECTIVES: To analyze the prevalence of peripheral arterial disease and poorly compressible arteries in hemodialysis patients, by comparing them to the Control Group. METHODS: It was a cross-sectional study with 78 hemodialysis patients and 88 non-hemodialysis patients with at least two risk factors for peripheral arterial disease (Control Group). To evaluate blood pressure, portable vascular Doppler and sphygmomanometer were used. The pressure was measured from the limb without arteriovenous fistula. The ankle-brachial index was calculated for each artery of the lower limb. It was considered normal ankle-brachial index from 0.9 to 1.3. RESULTS: We diagnosed peripheral arterial disease and poorly compressible arteries in 26.9 and 30.8% of hemodialysis patients and in 33 and 22.7% of the Control Group. In hemodialysis patients, we found abnormal ankle-brachial index in 75% of symptomatic patients (p=0.005), in 67.3% of men and 31% of women (p<0.005), in 78.6% of the elderly, 34.8% of young adults (p<0.01), and 76.9% of diabetics (p<0.005 versus nondiabetic). These patients had a higher prevalence of severe peripheral arterial disease than the Control Group. CONCLUSIONS: Abnormal ankle-brachial index was very prevalent in the groups studied; however, hemodialysis patients had more severe changes, when compared to the Control Group. Diabetes mellitus, male gender, and advanced age were important risk factors for abnormal ankle-brachial index in hemodialysis patients. The ankle-brachial index was a good method of screening for the studied changes; therefore, we suggest the routine use in the management of hemodialysis patients.