Possible association between dysnatremias and mortality during hospitalization in patients undergoing acute hemodialysis: analysis from a Peruvian retrospective cohort / Possível associação entre distúrbios do sódio e mortalidade hospitalar em pacientes submetidos a hemodiálise aguda: análise de uma coorte retrospectiva peruana

Abstract Objective: To evaluate the association between dysnatremias or dyschloremias and mortality during hospitalization in patients with acute kidney injury (AKI) or chronic kidney disease (CKD) undergoing acute hemodialysis. Methods: We carried out a retrospective cohort study on adult patients undergoing acute hemodialysis with AKI or CKD diagnosis at a public hospital in Lima, Peru. Dysnatremias were categorized as hyponatremia (Na < 135mmol/L) or hypernatremia (Na > 145mmol/L), and dyschloremias were defined as hypochloremia (Cl < 98 mmol/L) or hyperchloremia (Cl > 109mmol/L). The outcome of interest was mortality during hospitalization. We performed generalized lineal Poisson family models with bias-corrected and accelerated non-parametric bootstrap to estimate the risk ratios at crude (RR) and adjusted analysis (aRR) by gender, age, HCO3 (for all patients) and Liaño score (only for AKI) with CI95%. Results: We included 263 patients (mean age: 54.3 years, females: 43%): 191 with CKD and 72 with AKI. Mortality was higher in patients with AKI (59.7%) than in patients with CKD (14.1%). In overall, patients with hypernatremia had a higher mortality during hospitalization compared to those who had normal sodium values (aRR: 1.82, 95% CI: 1.17-2.83); patients with hyponatremia did not have different mortality (aRR: 0.19, 95% CI: 0.69-2.04). We also found that hyperchloremia (aRR: 1.35, 95% CI: 0.83-2.18) or hypochloremia (aRR: 0.66, 95% CI: 0.30-14.78) did not increase mortality in comparison to normal chloride values. No association between dysnatremias or dyschloremias and mortality during hospitalization was found in CKD and AKI subgroups. Conclusions: In our exploratory analysis, only hypernatremia was associated with mortality during hospitalization among patients with AKI or CKD undergoing acute hemodialysis.

Resumo Objetivo: Avaliar a associação entre distúrbios do sódio ou do cloro e mortalidade hospitalar de pacientes com insuficiência renal aguda (IRA) ou doença renal crônica (DRC) submetidos a hemodiálise aguda. Métodos: O presente estudo de coorte retrospectiva incluiu pacientes adultos submetidos a hemodiálise aguda com diagnóstico de IRA ou DRC em um hospital público de Lima, Peru. Os distúrbios do sódio foram classificados como hiponatremia (Na < 135mmol/L) ou hipernatremia (Na > 145mmol/L), enquanto os distúrbios do cloro foram classificados como hipocloremia (Cl < 98 mmol/L) ou hipercloremia (Cl > 109mmol/L). O desfecho de interesse foi mortalidade hospitalar. Utilizamos modelos de Poisson da família de modelos lineares generalizados com bootstrap não-paramétrico e correção de viés acelerado para estimar os riscos relativos na análise bruta (RR) e ajustada (RRa) para sexo, idade, HCO3 (para todos os pacientes) e escore de Liaño (apenas para IRA) com IC 95%. Resultados: Foram incluídos 263 pacientes (idade média 54,3 anos; 43% do sexo feminino), 191 com DRC e 72 com IRA. A mortalidade foi mais elevada nos pacientes com IRA (59,7%) do que nos indivíduos com DRC (14,1%). No geral, os pacientes com hipernatremia tiveram mortalidade hospitalar mais elevada do que os indivíduos com valores normais de sódio (RRa: 1,82; IC 95%: 1,17-2,83). Os pacientes com hiponatremia não apresentaram mortalidade diferente (RRa: 0,19; IC 95%: 0,69-2,04). Também identificamos que hipercloremia (RRa: 1,35; IC 95%: 0,83-2,18) e hipocloremia (RRa: 0,66; IC 95%: 0,30-14,78) não elevaram a mortalidade em comparação a indivíduos com níveis normais de cloro. Não foi encontrada associação entre distúrbios do sódio ou do cloro e mortalidade hospitalar nos subgrupos com DRC e IRA. Conclusões: Em nossa análise exploratória, apenas hipernatremia apresentou associação com mortalidade hospitalar em pacientes com IRA ou DRC submetidos a hemodiálise aguda.

Hipervitaminosis B12: Nuestra experiencia y una revisión / Hypervitaminosis B12. Our experience and a review

Los altos niveles de vitamina B12 o cobalamina, también denominado hipervitaminosis B12 es una anormalidad analítica frecuentemente subestimada. De acuerdo con la literatura algunas de las entidades relacionadas con este hallazgo son las neoplasias sólidas (primarias o metastásicas) y las enfermedades hematológicas agudas o crónicas. Otras causas incluyen la afección hepática, la gammapatía monoclonal de significación indeterminada, la insuficiencia renal y, con menor frecuencia, un exceso de consumo de vitamina B12, enfermedades inflamatorias o autoinmunes y los trastornos hematológicos transitorios (neutrofilia y eosinofilia secundaria). Este artículo informa sobre causas de hipervitaminosis B12, nuestra experiencia y hace una revisión de la literatura.

High serum levels of vitamin B12 or cobalamin, also called hypervitaminemia B12, is a frequently underestimated biological abnormality. According to the literature, some of the entities related to this finding are solid neoplasia (primary or metastatic) and acute or chronic hematological diseases. Other causes include liver disorders, monoclonal gammapathy of undetermined significance, renal failure and, less frequently, excess of vitamin B12 intake, inflammatory or autoimmune diseases, and transient hematological disorders (neutrophilia and secondary eosinophilia). This article reports on causes of hypervitaminosis B12, our experience and a review of the literature.

Is hypoalbuminemia a predictor for acute kidney injury after coronary bypass grafting in diabetes mellitus patients?

Abstract Objective: Acute kidney injury (AKI) is one of the most important complications after coronary artery bypass grafting (CABG) procedure. Serum albumin, which is an acute phase reactant, is suggested to be associated with AKI development subsequent to various surgical procedures. In this study, we research the relation between preoperative serum albumin levels and postoperative AKI development in diabetes mellitus (DM) patients undergoing isolated CABG. Methods: We included a total of 634 diabetic patients undergoing CABG (60.5±9.1 years, 65.1% male) into this study, which was performed between September 2009 and January 2014 in a single center. The relation between preoperative serum albumin levels and postoperative AKI development was observed. AKI was evaluated and diagnosed using the Kidney Disease: Improving Global Outcomes (KDIGO) classification. Results: AKI was diagnosed in 230 (36.3%) patients. Multiple logistic regression analysis was performed to determine the independent predictors of AKI development. Proteinuria (odds ratio [OR] and 95% confidence interval [CI], 1.066 [1.002-1.135]; P=0.043) and low preoperative serum albumin levels (OR and 95% CI, 0.453 [0.216-0.947]; P=0.035) were found to be independent predictors of AKI. According to the receiver operating characteristic curve analysis, albumin level <3mg/dL (area under the curve: 0.621 [0.572-0.669], P<0.001) had 83% sensitivity and 10% specificity on predicting the development of AKI. Conclusion: We observed that a preoperative low serum albumin level was associated with postoperative AKI development in patients with DM who underwent isolated CABG procedure. We emphasize that this adjustable albumin level should be considered before the operation since it is an easy and clinically implementable management for the prevention of AKI development.

Cistatina C sérica em cães criticamente enfermos em UTI / Cystatin C in critically ill dogs at UTI

A lesão renal aguda (IRA) é uma síndrome complexa, associada à progressão desfavorável, especialmente em cães na unidade de terapia intensiva (UTI) e apresenta alta morbidade e mortalidade. O diagnóstico de IRA requer combinação de testes laboratoriais, como a creatinina sérica e ureia, considerados pouco sensíveis e específicos para a detecção precoce de graus discretos durante a perda de função renal. O biomarcador cistatina C é considerado superior por apresentar uma melhor correlação com a taxa de filtração glomerular. No entanto, existem poucos estudos que demonstram a utilidade da cistatina C em cães na UTI. O objetivo deste estudo foi comparar a cistatina C com o nível sérico de creatinina para detectar o estágio inicial da IRA em cães em terapia intensiva. As dosagens desses analitos foram realizadas no momento da admissão, 24 e 48 horas após. A cistatina C apresentou concentrações mais elevadas em 78,6%, enquanto a creatinina sérica aumentou apenas em 28,5% dos cães. Os resultados demonstraram que a cistatina C pode ser utilizada para a detecção precoce de lesão renal aguda em cães de UTIs devido à sua maior sensibilidade em relação aos marcadores tradicionais.(AU)

Acute kidney injury (AKI) is a complex syndrome, associated with unfavorable progression, especially in dogs in the intensive care unit (ICU), and presents high morbidity and mortality. The diagnosis of AKI requires a combination of laboratory tests, such as serum creatinine and urea, considered to be poorly sensitive and specific for the early detection of discrete degrees during loss of renal function. The biomarker cystatin C is considered superior because it has a better correlation with the glomerular filtration rate. However, there are few studies that demonstrate the utility of cystatin C in dogs in ICU. The objective of this study was to compare cystatin C to creatinine serum level to detect early stage of AKI in dogs in an intensive care. Measurements of these analytes were performed at the time of admission, 24 and 48 hours after. Serum cystatin C presented higher concentrations in 78.6% while serum creatinina elevated in only 28.5% of the dogs. The results demonstrated that cystatin C can be used for the early detection of acute kidney injury in dogs in ICUs because of its greater sensitivity compared to traditional markers.(AU)

Are pre and postoperative platelet to lymphocyte ratio and neutrophil to lymphocyte ratio associated with early postoperative aki following cabg?

Abstract Objective: In this study, we investigated the role of two of the recent biomarkers of inflammation on the development of acute kidney injury in the early postoperative period of isolated coronary artery bypass grafting. Methods: Three hundred and eleven patients, who underwent isolated coronary artery bypass grafting with cardiopulmonary bypass by the same surgery team in our clinic between May 2010 and October 2014, who had a preoperative serum creatinine level lower than 1.5 mg/dl were included in the study. These patients' records were reviewed retrospectively. The diagnosis of acute kidney injury was performed according to the Kidney Disease Improving Global Outcomes 2012 Acute Kidney Injury Guideline criteria. Patients who developed acute kidney injury in the early postoperative period were classified as Group-1 (n=62) and the patients with normal postoperative renal functions were classified as Group-2 (n=249). The demographic data, body mass index, comorbidities, hematologic/biochemical profiles, preoperative ejection fraction, blood transfusion history, and operative data of the groups were compared. Univariate analyses were performed to determine significant clinical factors, and multiple logistic regression analyses were subsequently done to determine independent predictors of acute kidney injury. Results: Sixty-two (19.9%) patients developed acute kidney injury during the first 72 hours postoperatively. Multivariate logistic regression analyses revealed preoperative increased creatinine (P=0.0001), C-reactive protein (P=0.02), neutrophil-lymphocyte ratio (P=0.04) and platelet-lymphocyte ratio (P=0.002); increased postoperative first day leukocyte count (P=0.03), C-reactive protein levels (P=0.02), neutrophil-lymphocyte ratio (P=0.002), platelet-lymphocyte ratio (P=0.01) and increased intubation time (P=0.006) as independent predictors of early postoperative acute kidney injury in patients who underwent isolated coronary artery bypass grafting. Conclusion: The preoperative and postoperative increased levels of neutrophil-lymphocyte ratio and platelet-lymphocyte ratio which can be calculated by simple methods from routine blood analysis showed us that these parameters are independent biomarkers directly related to development of acute kidney injury in the early postoperative period.

An experimental study of ascorbic acid effects in acute renal failure under general anesthesia

Abstract Purpose: To evaluate the preventive effect of ascorbic acid on sevoflurane-induced acute renal failure in an experimental rat model. Methods: Twenty-four adult male Wistar rats were randomly distributed into three groups. Subjects were allocated into 3 groups: Group I received sevoflurane only, whereas Groups II and III had moderate (150 mg/kg) and high (300 mg/kg) doses of AA in addition to sevoflurane, respectively. Rhabdomyolysis and myohemoglobinuric ARF was formed by intramuscular administration of glycerol on the upper hind limb on the 15th minute of inhalation anesthesia. Biochemical parameters consisted of serum levels of blood urea nitrogen, creatinine, neutrophil gelatinase-associated lipocalin (NGAL), total antioxidant capacity (TAC), and protein carbonyl content. Histopathological variables were tubular necrosis, fibrin, and cast formation. Results: NGAL levels were significantly lower in Group III than Group II and Group I. On the other hand, TAC, PCO, urea and creatinine levels were notably higher in Group I compared with Groups II and III. There was a significant difference between 3 groups on frequencies of acute tubular necrosis (p=0.003), fibrin (p<0.001) and cast (p<0.001). Acute tubular necrosis and fibrin formation were more prominent in Group I. Casts were more common in Groups II and III. Conclusions: The ascorbic acid serve as a prophylactic agent against renal damage in patients receiving sevoflurane anesthesia and higher doses were associated with more apparent protective effects.

Attenuation of partial unilateral ureteral obstruction - induced renal damage with hyperbaric oxygen therapy in a rat model

ABSTRACT Objective: The objective of the present study was to evaluate the effectiveness of HBO therapy on biochemical parameters, renal morphology and renal scintigraphy in rats undergoing chronic unilateral partial ureteral obstruction (UPUO). Material and methods: Thirty-five rats were divided into five equal groups: Control group; Sham group; HBO group; UPUO group and UPUO/HBO group. The effects of HBO therapy were examined using biochemical parameters and histopathological changes. After calculating the score for each histopathological change, the total histopathological score was obtained by adding all the scores. In addition, dynamic renal scintigraphy findings were evaluated. Results: Serum parameters indicating inflammation, serum tumor necrosis factor- alpha, ischemia modified-albumin, IMA/albumin ratio and Pentraxin-3 levels, were observed to be high in the UPUO group and low in the UPUO/HBO treatment group. Similarly, in the treatment group, the reduction in malondialdehyde, total oxidant status and oxidative stress index levels and increase in total antioxidant capacity values were observed to be statistically significant compared to the UPUO group (p<0.001, p=0.007, p<0.001, p=0.001, respectively). The total score and apoptosis index significantly decreased after administration of HBO treatment. Dynamic 99mTc-MAG3 renal scintigraphy also showed convincing evidence regarding the protective nature of HBO against kidney injury. In the UPUO/HBO therapy group, the percentage contribution of each operated kidney increased significantly compared to the UPUO group (41.73% versus 32.72%). Conclusion: The findings of this study indicate that HBO therapy had a reno-protective effect by reducing inflammation and oxidative stress, and preserving renal function after renal tissue damage due to induction of UPUO.

Hemoglobin A1c Levels Predicts Acute Kidney Injury after Coronary Artery Bypass Surgery in Non-Diabetic Patients

Abstract INTRODUCTION: Elevated hemoglobin A1c levels in patients with diabetes mellitus have been known as a risk factor for acute kidney injury after coronary artery bypass grafting. However, the relationship between hemoglobin A1c levels in non-diabetics and acute kidney injury is under debate. We aimed to investigate the association of preoperative hemoglobin A1c levels with acute kidney injury in non-diabetic patients undergoing isolated coronary artery bypass grafting. METHODS: 202 non-diabetic patients with normal renal function (serum creatinine <1.4 mg/dl) who underwent isolated coronary bypass were analyzed. Hemoglobin A1c level was measured at the baseline examination. Patients were separated into two groups according to preoperative Hemoglobin A1c level. Group 1 consisted of patients with preoperative HbA1c levels of < 5.6% and Group 2 consisted of patients with preoperative HbA1c levels of ≥ 5.6%. Acute kidney injury diagnosis was made by comparing baseline and postoperative serum creatinine to determine the presence of predefined significant change based on the Kidney Disease Improving Global Outcomes (KDIGO) definition. RESULTS: Acute kidney injury occurred in 19 (10.5%) patients after surgery. The incidence of acute kidney injury was 3.6% in Group 1 and 16.7% in Group 2. Elevated baseline hemoglobin A1c level was found to be associated with acute kidney injury (P=0.0001). None of the patients became hemodialysis dependent. The cut off value for acute kidney injury in our group of patients was 5.75%. CONCLUSION: Our findings suggest that, in non-diabetics, elevated preoperative hemoglobin A1c level may be associated with acute kidney injury in patients undergoing coronary artery bypass grafting. Prospective randomized studies in larger groups are needed to confirm these results.

Troponin I serum levels predict the need of dialysis in incident sepsis patients with acute kidney injury in the intensive care unit / Níveis séricos de troponina predizem a necessidade de diálise em pacientes sépticos com injúria renal aguda renal na unidade de terapia intensiva

Abstract Introduction: Sepsis, an extremely prevalent condition in the intensive care unit, is usually associated with organ dysfunction, which can affect heart and kidney. Objective: To determine whether the cardiac dysfunction and the Troponin I forecast the occurrence of acute renal failure in sepsis. Methods: Cardiac dysfunction was assessed by echocardiography and by the serum troponin I levels, and renal impairment by AKIN criteria and the need of dialysis. Twenty-nine patients with incident sepsis without previous cardiac or renal dysfunction were enrolled. Results and Discussion: Patients averaged 75.3 ± 17.3 years old and 55% were male. Median APACHE II severity score at ICU admission was 16 (9.7 - 24.2) and mortality rate in 30 days was 45%. On the fifth day, 59% had ventricular dysfunction. Troponin serum levels on day 1 in the affected patients were 1.02 ± 0.6 ng/mL compared with 0.23 ± 0.18 ng/mL in patients without heart dysfunction (p = 0.01). Eighteen out of 29 patients (62%) underwent renal replacement therapy (RRT) and the percent of patients with ventricular dysfunction who required dialysis was higher (94% vs. 16%, p = 0.0001). Values of troponin at day 1 were used to develop a ROC curve to determine their ability to predict the need of dialysis. The area under the curve was 0.89 and the cutoff value was 0.4 ng/mL. Conclusion: We found that an elevation in serum troponin levels, while guarding a relationship with ventricular dysfunction, can be a precious tool to predict the need for dialysis in sepsis patients.

Resumo Introdução: Sepse é uma condição extremamente prevalente na unidade de terapia intensiva, geralmente associada com disfunção orgânica que pode afetar o coração e os rins. Objetivo: Determinar se a disfunção cardíaca e a troponina I preveem a ocorrência de lesão renal aguda na sepse. Métodos: A disfunção cardíaca foi avaliada por ecocardiografia e pelos níveis de troponina I sérica; e a lesão renal aguda pelos critérios AKIN e necessidade de diálise. Vinte e nove pacientes com sepse foram recrutados. Resultados e Discussão: Os pacientes tinham em média 75,3 ± 17,3 anos e 55% eram do sexo masculino. O escore de gravidade APACHE II médio de internação na UTI foi de 16 (9,7-24,2) e taxa de mortalidade em 30 dias foi de 45%. No quinto dia, 59% tinham disfunção ventricular. O nível sérico de troponina no dia 1 nos pacientes afetados foi de 1,02 ± 0,6 ng/mL em comparação com 0,23 ± 0,18 ng/mL em pacientes sem disfunção cardíaca (p = 0,01). Dezoito dos 29 pacientes (62%) foram submetidos à terapia renal substitutiva e a porcentagem de pacientes com disfunção ventricular que necessitou de diálise foi maior (94% vs. 16%, p = 0,0001) nesse grupo. A área sob uma curva ROC desenhada para prever a necessidade de diálise de acordo com o nível sérico de troponina no dia 1 foi de 0,89 e o valor de corte foi de 0,4 ng/mL. Conclusão: Verificou-se que uma elevação nos níveis séricos de troponina pode prever a necessidade de diálise em pacientes sépticos com lesão renal aguda.

Renal biomarkers of male and female Wistar rats (Rattus norvegicus) undergoing renal ischemia and reperfusion

PURPOSE: To investigate biomarkers of acute renal injury in Wistar rats, subjected to left renal ischemia for 10 minutes, and then compare reperfusion at 24 hours, and at 5, 7, 14 and 21 days after the procedure. METHODS: Eight female and male rats between 60 and 81 days old were used in the Central Animal Facility of the UFMS. Assessed biomarkers included urine protein, urea, creatinine, glucose, sodium, potassium, urine alkaline phosphatase and gamma-glutamyl transferase activities, and protein-to-creatinine ratio; and in serum: urea, creatinine, sodium and potassium, fractional excretion of sodium, potassium, urine flow and creatinine clearance. RESULTS: Greater variance was observed in the parameters at 24 hours and at five days (p<0.05) after reperfusion. On the 21st day, these parameters approximated those obtained for the control group. CONCLUSIONS: Renal ischemia for 10 minutes was sufficient to raise urine levels of protein, glucose, fractional excretion of potassium, urea, creatinine clearance, urine activity of gamma-glutamyltransferase and alkaline phosphatase enzymes in the first 24 hours, up to five days after reperfusion, which may indicate risk of acute kidney injury, according to the RIFLE classification. .

Inverse association between serum creatinine and mortality in acute kidney injury / Associação inversa entre creatinina sérica e mortalidade na lesão renal aguda

Introduction: Sepsis is a leading precipitant of Acute Kidney Injury (AKI) in intensive care unit (ICU) patients, and is associated with a high mortality rate. Objective: We aimed to evaluate the risk factors for dialysis and mortality in a cohort of AKI patients of predominantly septic etiology. Methods: Adult patients from an ICU for whom nephrology consultation was requested were included. End-stage chronic renal failure and kidney transplant patients were excluded. Results: 114 patients were followed. Most had sepsis (84%), AKIN stage 3 (69%) and oliguria (62%) at first consultation. Dialysis was performed in 66% and overall mortality was 70%. Median serum creatinine in survivors and non-survivors was 3.95 mg/dl (2.63 - 5.28) and 2.75 mg/dl (1.81 - 3.69), respectively. In the multivariable models, oliguria and serum urea were positively associated with dialysis; otherwise, a lower serum creatinine at first consultation was independently associated with higher mortality. Conclusion: In a cohort of septic AKI, oliguria and serum urea were the main indications for dialysis. We also described an inverse association between serum creatinine and mortality. Potential explanations for this finding include: delay in diagnosis, fluid overload with hemodilution of serum creatinine or poor nutritional status. This finding may also help to explain the low discriminative power of general severity scores - that assign higher risks to higher creatinine levels - in septic AKI patients. .

Introdução: A sepse é considerada importante causa de Lesão Renal Aguda (LRA) em pacientes internados em Unidade de Terapia Intensiva (UTI), sendo esta síndrome associada à elevada mortalidade. Objetivo: Avaliar os fatores de risco para diálise e mortalidade em uma coorte de pacientes com LRA de etiologia predominantemente séptica. Métodos: Pacientes adultos com LRA internados em UTI avaliados pela equipe da nefrologia, sendo excluídos portadores de doença renal crônica terminal e transplantados renais. Resultados: 114 pacientes foram incluídos. A maioria apresentou sepse (84%), estágio AKIN 3 (69%) e oligúria (69%) na primeira consulta nefrológica. Diálise foi realizada em 66%; a mortalidade geral foi de 70%. A creatinina mediana nos sobreviventes e não sobreviventes foi 3,95 mg/dl (2,63 - 5,28) and 2,75 mg/dl (1,81 - 3,69). Nos modelos multivariáveis, oligúria e a ureia sérica foram positivamente associadas com diálise; entretanto, menor creatinina sérica na primeira consulta foi independentemente associada com maior mortalidade. Conclusão: Nesta coorte de pacientes com LRA de etiologia predominantemente séptica, oligúria e a ureia sérica foram as principais indicações de diálise. Também observamos associação inversa entre a creatinina sérica e mortalidade. Possíveis justificativas para esse achado são avaliação nefrológica tardia, sobrecarga volêmica com hemodiluição da creatinina sérica ou desnutrição. Este achado pode, ainda, ajudar a explicar o baixo poder discriminativo dos escores gerais de gravidade, que atribuem maior pontuação a valores maiores de creatinina, em pacientes críticos com LRA. .

Acute kidney injury based on KDIGO (Kidney Disease Improving Global Outcomes) criteria in patients with elevated baseline serum creatinine undergoing cardiac surgery / Lesão renal aguda baseada nos critérios KDIGO (Kidney Disease: Improving Global Outcomes) em pacientes com creatinina sérica elevada submetidos à cirurgia cardíaca

Introduction: Preoperatively elevated serum creatinine (SCr) is considered an independent risk factor for morbidity and mortality after cardiac surgery. The aim of this study was to apply the Kidney Disease Improving Global Outcomes classification for acute kidney injury in a population of patients with preoperatively elevated serum creatinine who underwent cardiac surgery (coronary artery bypass grafting or cardiac valve surgery) and to evaluate the acute worsening of renal function as a predictor of 30-day mortality. Methods: This was a single-center retrospective study that included patients from the Postoperative Cardiac Surgery Intensive Care Unit of the Hospital de Base, São José do Rio Preto Medical School. Demographics, type of surgery, laboratory data and pre, peri and postoperative data were obtained from a prospectively collected database. From January 2003 to June 2013, 2,878 patients underwent cardiac surgery, either coronary artery bypass grafting or cardiac valve surgery, at the Hospital de Base of São José do Rio Preto Medical School. Out of those, 918 showed elevated preoperative serum creatinine, with SCr > 1.30 mg/dL for men and > 1.00 mg/dL for women. Five hundred and forty nine patients (60%) undergoing coronary artery bypass grafting and 369 patients (40%) undergoing cardiac valve surgery. A Multivariate Cox Proportional Hazard Model (stepwise) was used to assess the relationship between AKI and mortality at 30 days. Results: Out of the 918 patients studied, 391 (43%) had postoperative AKI: 318 (35%) had Kidney Disease Improving Global Outcomes stage 1, 27 (2.9%) had Kidney Disease Improving Global Outcomes stage 2, and 46 (5.0%) had Kidney Disease Improving Global Outcomes stage 3. Patients in every stage of acute kidney injury showed progressive increase in EuroSCORE values, 30-day mortality ratescardiopulmonary bypass duration, and intensive care length of stay. Among patients classified ...

Introdução: Creatinina sérica (CSr) elevada no período pré-operatório é considerada um fator de risco independente para morbidade e mortalidade em cirurgia cardíaca. Avaliar o impacto da lesão renal aguda pelos critérios Kidney Disease Improving Global Outcomes como preditor de mortalidade em 30 dias em pacientes submetidos à revascularização miocárdica ou cirurgia valvar com creatinina sérica pré-operatória elevada. Métodos: Este foi um estudo retrospectivo de centro único que incluiu pacientes da Unidade de Cuidados Intensivos em Pós-operatório de Cirurgia Cardíaca do Hospital de Base, Faculdade de Medicina de São José do Rio Preto. Dados demográficos, tipos de cirurgia, dados laboratoriais e informações pré, peri e pós-operatórias foram obtidos a partir de uma coleta prospectiva de banco de dados. Foram considerados 2878 pacientes consecutivamente submetidos à revascularização miocárdica ou cirurgia valvar no período de janeiro de 2003 a junho de 2013. Destes, 918 indivíduos apresentavam creatinina sérica alterada no pré-operatório (CrS > 1.30 mg/dL para homens e > 1.00 mg/dL para mulheres), compreendendo 549 pacientes (60%) submetidos à revascularização miocárdica e 369 pacientes (40%) submetidos à cirurgia valvar. O modelo de riscos proporcionais de Cox foi utilizado para avaliar a relação entre lesão renal aguda e mortalidade em 30 dias. Resultados: Nesta casuística, 391 pacientes (43%) apresentaram lesão renal aguda no pós-operatório, sendo 318 (35%) Kidney Disease Improving Global Outcomes estágio 1, 27 (2,9%) Kidney Disease Improving Global Outcomes estágio 2 e 46 (5,0%) Kidney Disease Improving Global Outcomes estágio 3. EuroSCORE, mortalidade em 30 ...

Serum cystatin C is a sensitive early marker for changes in the glomerular filtration rate in patients undergoing laparoscopic surgery

OBJECTIVE: Pneumoperitoneum during laparoscopy results in transient oliguria and decreased glomerular filtration and renal blood flow. The presence of oliguria and elevated serum creatinine is suggestive of acute renal injury. Serum cystatin C has been described as a new marker for the detection of this type of injury. In this study, our aim was to compare the glomerular filtration rate estimated using cystatin C levels with the rate estimated using serum creatinine in patients with normal renal function who were undergoing laparoscopic surgery. METHODS: In total, 41 patients undergoing laparoscopic cholecystectomy or hiatoplasty were recruited for the study. Blood samples were collected at three time intervals: first, before intubation (T1); second, 30 minutes after the establishment of pneumoperitoneum (T2); and third, 30 minutes after deflation of the pneumoperitoneum (T3). These blood samples were then analyzed for serum cystatin C, creatinine, and vasopressin. The Larsson formula was used to calculate the glomerular filtration rate based on the serum cystatin C levels, and the Cockcroft-Gault formula was used to calculate the glomerular filtration rate according to the serum creatinine levels. RESULTS: Serum cystatin C levels increased during the study (T1 = T2<T3; p<0.05), whereas serum creatinine levels decreased (T1 = T2>T3; p<0.05). The calculated eGlomerular filtration rate-Larsson decreased, whereas the eGlomerular filtration rate-Cockcroft-Gault increased. There was no correlation between cystatin C and serum creatinine. Additionally, Pearson's analysis showed a better correlation between serum cystatin C and the eGlomerular filtration rate than between serum creatinine and the eGlomerular filtration rate. CONCLUSION: This study demonstrates that serum cystatin C is a more sensitive indicator of changes in the glomerular filtration rate than serum creatinine is in patients with normal ...

Determinantes precoces en el desarrollo de injuria renal aguda durante la sepsis abdominal experimental / Early determinants of acute kidney injury during experimental intra-abdominal sepsis

Background: Sepsis-induced acute kidney injury (AKI) is an early and frequent organ dysfunction, associated with increased mortality. Aim: To evaluate the impact of macrohemodynamic and microcirculatory changes on renal function and histology during an experimental model of intra-abdominal sepsis. Material and Methods: In 18 anaesthetized pigs, catheters were installed to measure hemodynamic parameters in the carotid, right renal and pulmonary arteries. After baseline assessment and stabilization, animals were randomly divided to receive and intra-abdominal infusion of autologous feces or saline. Animals were observed for 18 hours thereafter. Results: In all septic animals, serum lactate levels increased, but only eight developed AKI (66%). These animals had higher creatinine and interleukin-6 levels, lower inulin and para-aminohippurate clearance (decreased glomerular filtration and renal plasma flow), and a negative lactate uptake. Septic animals with AKI had lower values of mean end arterial pressure, renal blood flow and kidney perfusion pressure, with an associated increase in kidney oxygen extraction. No tubular necrosis was observed in kidney histology. Conclusions: The reduction in renal blood flow and renal perfusion pressure were the main mechanisms associated with AKI, but were not associated with necrosis. Probably other mechanisms, such as microcirculatory vasoconstriction and inflammation also contributes to AKI development.

Acute Kidney Injury after Using Contrast during Cardiac Catheterization in Children with Heart Disease

Acute kidney injury (AKI) is closely associated with the mortality of hospitalized patients and long-term development of chronic kidney disease, especially in children. The purpose of our study was to assess the evidence of contrast-induced AKI after cardiac catheterization in children with heart disease and evaluate the clinical usefulness of candidate biomarkers in AKI. A total of 26 children undergoing cardiac catheterization due to various heart diseases were selected and urine and blood samples were taken at 0 hr, 6 hr, 24 hr, and 48 hr after cardiac catheterization. Until 48 hr after cardiac catheterization, there was no significant increase in serum creatinine level in all patients. Unlike urine kidney injury molecule-1, IL-18 and neutrophil gelatinase-associated lipocalin, urine liver-type fatty acid-binding protein (L-FABP) level showed biphasic pattern and the significant difference in the levels of urine L-FABP between 24 and 48 hr. We suggest that urine L-FABP can be one of the useful biomarkers to detect subclinical AKI developed by the contrast before cardiac surgery.

Biomarcadores da injúria renal aguda / Biomarkers of acute kidney injury

A creatinina continua a ser o padrão laboratorial para diagnóstico da injúria renal aguda (IRA). Esforços para prevenção da nefrotoxicidade foram prejudicados pelo atraso no diagnóstico da IRA por critérios utilizando somente a creatinina como marcador, havendo, por isso, grande interesse em identificar mais precocemente biomarcadores confiáveis. Além disso, o tratamento precoce da IRA pode ser correlacionado com um melhor prognóstico e a identificação de biomarcadores para um diagnóstico precoce pode melhorar a eficácia de estratégia terapêutica. Portanto, torna-se imperativo encontrar biomarcadores que possam estratificar corretamente o grau de lesão renal e o risco de desenvolver doença renal crônica (DRC). Aqui, nós revisamos as principais características dos emergentes biomarcadores em nefrologia.

Creatinine remains the standard for laboratory diagnosis of AKI. Efforts to prevent nephrotoxicity have been harmed by the delay in the diagnosis of AKI criteria by using only the creatinine as a marker, therefore there is great interest in identifying early reliable biomarkers. Moreover, early treatment of ARF can be correlated with a better prognosis and identification of biomarkers for early diagnosis would improve the efficacy of a therapeutic strategy. Thus, it becomes imperative to find biomarkers that can stratify correctly the extent of renal damage that each patient has suffered and the risk of developing chronic kidney disease (CKD). Here, we review the main features of emerging biomarkers in nephrology.

Early initiation of dialysis: mortality and renal function recovery in acute kidney injury patients / Início precoce da diálise: mortalidade e recuperação da função renal em pacientes com lesão renal aguda

INTRODUCTION: The decision of when to start dialysis in Acute Kidney Injury (AKI) patients with overt uremia is strongly established, however, when blood urea nitrogen (BUN) levels is < 100 mg/dL the timing of initiation of dialysis remains uncertain. Purpose: The aim of this study was to assess mortality and renal function recovery AKI patients started on dialysis at different BUN levels. METHODS: This was a retrospective study performed at Medical School Hospital, São Paulo, Brazil, enrolling 86 patients underwent to dialysis. RESULTS: Dialysis was started when BUN < 75 mg/dl in 23 patients (Group I) and BUN > 75 mg/dl in 63 patients (Group II). Hypervolemia and mortality were higher in Group I than in Group II (65.2% vs. 14.3% - p < 0.05, 39.1% vs. 68.9%- p < 0.05, respectively). Among survivors, the rate of renal function recovery was higher in Group I (71.4% and 36.8%, respectively - p < 0.05). Multivariate analysis showed that sepsis, age > 60 years, peritoneal dialysis and BUN > 75 mg/dl at dialysis initiation were independently related with mortality. CONCLUSIONS: Lower mortality and higher renal function recovery rates were associated with early dialysis initiated at lower BUN leves in AKI patients.

INTRODUÇÃO: A decisão de quando iniciar a diálise em pacientes com lesão renal aguda (LRA) que apresentam síndrome urêmica está bem estabelecida, entretanto, com ureia < 200 mg/dl o melhor momento para iniciar a diálise torna-se incerto. OBJETIVO: Este estudo teve como objetivo avaliar a mortalidade e a recuperação da função renal em pacientes com LRA, cujo início da diálise ocorreu em diferentes níveis de ureia. MÉTODOS: Estudo retrospectivo desenvolvido em hospital escola, no estado de São Paulo, Brasil, envolvendo 86 pacientes submetidos à diálise. RESULTADOS: A diálise foi iniciada com uréia > 150 mg/dl em 23 pacientes (grupo I) e uréia > 150 mg/dl em 63 pacientes (grupo II). Hipervolemia e mortalidade foram mais frequentes no grupo I que no grupo II (65,2 x 14,2% - p < 0,05; 39,1 x 68,9% - p < 0,05, respectivamente). Entre os sobreviventes, a recuperação renal foi maior no grupo I (71,4 e 36,8%, respectivamente, p < 0,05). A análise multivariada mostrou risco independente de mortalidade relacionado à sepse, idade > 60 anos, diálise peritoneal e uréia > 150 mg/dl no início da diálise. CONCLUSÃO: Menor mortalidade e maior recuperação renal estão associadas com o diálise iniciada precocemente, conforme baixos níveis de ureia, em pacientes com LRA.

Injuria renal aguda en la sepsis grave / Acute kidney injury in severe sepsis

La sepsis afecta al 40% de los pacientes críticos, siendo su mortalidad de aproximadamente un 30% en el caso de la sepsis grave, y de 75% con injuria renal aguda, la cual sucede en el 20-51% de los casos. Se realizó un estudio prospectivo, observacional, longitudinal, en 80 pacientes sépticos graves en el lapso de 1 año para determinar el desarrollo de injuria renal aguda y su relación con la mortalidad; correlacionar antecedentes clínicos y variaciones del laboratorio con la mortalidad; determinar la tasa de mortalidad de la sepsis grave; relacionar óbito y foco séptico primario; evaluar la predictibilidad de mortalidad según niveles de creatinina de ingreso y sus variaciones finales. Se definieron dos grupos: Obito (n = 25) y No-óbito (n = 55). Analizados según la creatinina de ingreso, 39 tenían valores normales de creatinina (10 óbitos) y 41 la presentaban elevada (15 óbitos); según la creatinina de egreso, 48 presentaron creatinina normal y fallecieron 7, mientras que 32 tenían daño renal agudo, de los cuales 18 fallecieron. De los 25 pacientes fallecidos, el 72% presentaron daño renal. De éstos, 7 pacientes vivos y 2 fallecidos requirieron hemodiálisis. El foco primario más frecuente fue el respiratorio (26.4%). El desarrollo de daño renal es un alto predictor de mortalidad en la sepsis, independientemente de los valores iniciales de creatinina. Edad más avanzada, hipertensión arterial, score APACHE más elevado, anemia más grave, hipoalbuminemia, hiperfosfatemia e hiperkalemia se asociaron a mayor mortalidad. La mortalidad global fue 31.3%. La imposibilidad de identificar el foco séptico primario se asoció a mayor mortalidad. El foco respiratorio se relacionó a mayor riesgo de requerir hemodiálisis.

Sepsis affects 40% of critically ill patients, with a reported mortality of approximately 30% in severe sepsis, raising to 75% when acute kidney injury ensues, which occurs in about 20-51% of cases. The present study consists on a one-year prospective, observational, longitudinal trial undergone in 80 severe septic patients to determine the risk of development of acute kidney injury and its relationship with mortality; the association of the clinical course and blood parameter variations with mortality; the severe sepsis mortality rate; an eventual correlation between death and septic focus, and to assess mortality predictibility based on initial creatinine levels and final variations. Two groups were defined: Dead (n=25) and Not-dead (n=55). According to creatinine on admission, 39 subjects presented with normal creatinine levels (10 deaths) and 41 presented elevated creatinine measurements (15 deaths); regarding final creatinine levels, 48 presented normal levels and 7 patients died, while 32 developed acute kidney injury, with 18 deaths. Of the total of 25 deaths, 72% presented renal injury. Seven alive patients and 2 deceased patients required hemodialysis. The most frequent primary septic focus was the airway (26.4%). The development of kidney injury is a high predictor of mortality in sepsis, independent of initial serum creatinine levels. Older patients, hypertension, a higher APACHE score, a more severe degree of anemia, hypoalbuminemia, hyperphosphatemia and hyperkalemia were associated with a higher mortality rate. The global mortality was: 31.3%. The failure to identify the primary septic focus was associated with higher mortality. The respiratory focus was related with a higher risk to require hemodialysis.

The investigation of macrophage infiltration in the early phase of ischemic acute renal failure in mice

BACKGROUND/AIMS: Inflammation plays a key role in ischemic acute renal failure (ARF). The present study investigated the infiltration of macrophages in the early phase of ischemic ARF in mice. METHODS: Ischemic ARF was induced by renal clamping for 22 min, while the control mice underwent sham surgery (no clamping). The serum creatinine and blood urea nitrogen (BUN) levels were measured in the control and post-ischemia mice. Immunofluorescence staining was used to measure the number of CD 11b-positive cells in the kidney tissue sections to determine the amount of post-ischemic macrophage infiltration. Lipo-Cl2MBP (clodronate) for macrophages depletion was injected via a tail vein 5 d before ischemia induction and again 2 d before ischemia induction. RESULTS: The study found that the post-ischemia mice had higher levels of serum creatinine and BUN at 16 and 24 h compared to the controls. Immunofluorescence staining showed there were more macrophages in the post-ischemic tissue at 2, 8, 16 and 24 h compared to the control tissue, and that most of these macrophages were located in the outer medulla. The mice treated with clodronate prior to ischemia induction were found to have lower levels of serum creatinine compared to those mice that weren't treated with clodronate. CONCLUSIONS: There was significant infiltration of macrophages from the early phase of ischemic ARF, and this peaked at 16-24 h. Macrophage depletion using clodronate was protective against ischemic ARF.