Is race adjustment necessary to estimate glomerular filtration rate in South Brazilians?

BACKGROUND AND AIMS: Race coefficients (RC) in equations to estimate glomerular filtration rate (GFR) have been highly questioned. We aimed to evaluate the performance of three equations, namely 2009 Chronic Kidney Disease Epidemiology Collaboration (2009 CKD-EPI), 2021 CKD-EPI, and European Kidney Function Consortium (EKFC) in self-reported Black and White Brazilians. MATERIALS AND METHODS: Our cross-sectional study compared estimated GFR (eGFR) with 51Cr-EDTA measured GFR (mGFR) in healthy adults, patients with type 2 diabetes mellitus with or without chronic kidney disease (CKD), and in non-diabetic individuals with CKD. The performance of these equations was assessed using Bland-Altman plots, Lin's concordance correlation coefficient (CCC), bias, P30, and P15 accuracy. RESULTS: Three hundred six White adults (aged 53 ± 17 years, 55% women, mean mGFR: 83 ± 32 mL/min/1.73 m2) and 48 Black participants (aged 53 ± 17 years, 58% women, mGFR: 90 ± 34 mL/min/1.73 m2) were included. No equation achieved the desirable P30 accuracy value of 90%, neither in White (2009 CKD-EPI:78%, 2021 CKD-EPI:76% and EKFC:77%, p = 0.368) nor in Black volunteers (respective values of 77%, 75%, and 77%; p = 0.882). The 2009 CKD-EPI showed the best performance in Black participants (bias: 4.04; CCC: 0.848), whereas the 2021 CKD-EPI performed better in Whites, with smaller bias (1.45), and better concordance correlation coefficient (0.790). The EKFC presented the worst performance. All equations underdiagnosed advanced CKD in White participants, but not in Black. CONCLUSIONS: The 2021 CKD-EPI does not outperform the 2009 CKD-EPI. Instead, it underestimated the occurrence of CKD in White participants. Thus, we do not recommend replacing the 2009 with the new 2021 CKD-EPI in the Brazilian population.

A Web-Based Platform to Collect Data from ESRD Patients Undergoing Dialysis: Methods and Preliminary Results from the Brazilian Dialysis Registry.

INTRODUCTION: The methods and initial results of a web-based platform to collect data from patients receiving maintenance dialysis in Brazil are reported. METHODS: Companies providing management software for dialysis centers adapted their system to comply with a formulary of the Brazilian Society of Nephrology. Baseline and follow-up individual patients' data were transmitted via Internet on monthly bases to the coordinating center from 2011 to 2017. RESULTS: 73 dialysis centers provided information of 24,930 patients: 57% were male, 28% were 64 years old or older, and 13% were overweight/obese. Median dialysis vintage was 28 months. Hemodialysis was the most frequent initial therapy (93%) with venous catheters used in 64% of cases. Conventional hemodialysis remained the main current therapy (90%). Seropositivity for hepatitis C, hepatitis B, and HIV was 2.7%, 1.1%, and 0.5%, respectively. Erythropoietin (53.9%), iron (35.1%), and sevelamer (23.4%) were the most used medications. Hemoglobin < 100 g/L and serum P > 1.74 mmol/L were present in 33.1% and 36.6% of the cases, respectively. The 5-year survival of incident cases (n = 7,538) was 57%. CONCLUSION: The initiative represents an innovative strategy to collect clinical and epidemiologic data of dialysis patients which may be applied to other settings and provides information that can contribute to guiding clinical practice and health care policy.

Performance of CKD-EPI equation to estimate glomerular filtration rate as compared to MDRD equation in South Brazilian individuals in each stage of renal function.

BACKGROUND: The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation seems to correct the overdiagnosis of chronic kidney disease (CKD) provided by Modification of Diet in Renal Disease (MDRD) equation. However, this point has not been tested in some ethnic groups. This study investigated the performance of MDRD and CKD-EPI equations in South Brazilian individuals. METHODS: This cross-sectional study included 354 individuals including healthy volunteers, diabetic and non-diabetic individuals with or without CKD. Glomerular filtration rate (GFR) was measured by the 51Cr-EDTA single-injection method (51Cr-GFR). Accuracy (P30), bias, and Bland-Altman agreement plots were evaluated. RESULTS: In the group as a whole, 51Cr-GFR was 87±37 (6-187), CKD-EPI eGFR, 82±30 (6-152), and MDRD eGFR, 77±28 (6-156) mL/min/1.73 m2 (p<0.001 for all comparisons). Analyzing the subset of individuals with 51Cr-GFR <60 mL/min/1.73 m2, P30 values were, respectively, 76% and 84% for MDRD and for CKD-EPI (p<0.001) while for 51Cr-GFR ≥60 mL/min/1.73 m2, P30 values were 57.5% for both equations (p=1.000). For MDRD and CKD-EPI, mean bias were negative for GFRs <60 (-11 vs. -12, p=0.221) and positive for values >60 (16 vs. 9, p<0.001). In multivariate analysis, absolute bias was unfavorably influenced by measured GFR >60 (for MDRD) and being diabetic or younger (for CKD-EPI). CONCLUSIONS: CKD-EPI reduces GFR underestimation in individuals with GFRs >60, but still presents a quite low accuracy at this GFR range. Moreover, it tends to overestimate GFR in subjects with GFRs <60 mL/min/1.73 m2. CKD stages 1 and 2, diabetes and young age had a negative influence on the performance of the equations.

Effect of peripheral and respiratory muscle training on the functional capacity of hemodialysis patients.

Patients on hemodialysis (HD) show changes in muscle structure and function reducing their functional capacity. This study was conduted to assess the effects of respiratory muscle training (RMT) and peripheral muscle training (PMT) during dialysis on functional parameters, inflammatory state, and quality of life (QoL) in patients on HD. Randomized controlled trial included 39 patients on HD, and they were divided into three groups: RMT (n = 11), PMT (n = 14), and controls (C, n = 14). Training was performed during the HD session for 10 weeks. Maximal inspiratory pressure (PI(max)), maximal expiratory pressure (PE(max)), forced vital capacity (FVC), six-minute walk test (6MWT), Kt/V(sp), biochemical parameters, and inflammatory state (i.e., level of high sensitivity C-reactive protein) were evaluated. Variation from baseline was calculated by Analysis of Covariance (ANCOVA). The ΔPI(max) was 22.5 ± 3.2, 9.1 ± 2.9, and -4.9 ± 2.8 cmH(2)O in the RMT, PMT and C, respectively (p < 0.001); ΔPE(max) was 10.8 ± 6.6, 3.7 ± 5.9, and -15.6 ± 5.9 cmH(2)O respectively (p = 0.014). The Δ6MWT was significantly greater in RMT and PMT (65.5 ± 9; 30.8 ± 8 m) than in C (-0.5 ± 8.1 m), p < 0.001. Although biochemical parameters decreased after training, Kt/V remained unchanged. CRP decreased only in the RMT and PMT groups. There was a significant increase in QoL scores in the training groups (vs. C) in energy/fatigue (p = 0.002), sleep (p < 0.001), pain (p < 0.001), and list of symptoms/problems (p = 0.014). A short period of RMT or PMT during HD significantly improved functional capacity, with RMT showing greater effect than PMT. Muscle training improved biochemical and inflammatory markers, but a direct cause and effect relationship could not be established by this study.

Health-related quality of life and dialysis dependence in critically ill patient survivors of acute kidney injury.

BACKGROUND: Acute kidney injury is a common disorder in critical ill patients and it is associated with high mortality. Few studies focus on long-term perspectives such as health-related quality of life (HRQOL) and dialysis dependence. METHODS: Prospective cohort study at the intensive care unit (ICU) of a Brazilian tertiary hospital. All patients requiring dialysis over a 2-year enrollment period were included. The Medical Outcomes Study 36-Item Short Form Health Survey (SF-36) assessed the HRQOL along with patient status and dialysis dependence. RESULTS: 408 patients (11%) required dialysis. ICU, hospital, and after-hospital cumulative fatality rates were 70%, 74%, and 80%, respectively. A total of 68 of 82 eligible patients were interviewed in an average of 256 days after hospital discharge, while 8 patients (11.8%) were in regular dialysis. There was no association between Acute Physiology and Chronic Health Evaluation II score, use of vasopressors, mechanical ventilation, creatinine, number of dialysis, and SF-36 scores. Better HRQOL was associated with previous conditions, as younger age and no chronic kidney disease; condition related to severity of acute illness, as have not had sepsis, short period at ICU, and hospital; and conditions after discharge, considered working currently. CONCLUSIONS: Previous chronic kidney disease was strongly associated with permanence in dialysis and lower further HRQOL. Younger survivors who have not had sepsis or long stays at hospitals, able to return to their jobs, had better HRQOL.

Síndrome de Nutcracker: relato de caso / Nutcracker of syndrome: case report

JUSTIFICATIVA E OBJETIVOS: A síndrome do pinçamento aorto-mesentérico da veia renal esquerda - síndrome de Nutcracker - acarreta hipertensão venosa renal e consequentemente o aparecimento de sintomas como dor no baixo ventre, varicocele e hematúria. A dificuldade no diagnóstico nestes casos pode atrasar o tratamento, submeter o paciente a procedimentos desnecessários e resultar em complicações relacionadas à compressão venosa. O objetivo deste estudo foi relatar o caso de um paciente atendido no ambulatório de Nefrologia do Hospital de Clínicas de Porto Alegre. RELATO DO CASO: Paciente do sexo masculino, 22 anos, branco, com queixa de dor no baixo ventre, hematúria e obstrução urinária; com investigação básica etiológica inconclusiva. Investigações futuras, após aproximadamente dois anos de sintomas, revelaram a síndrome de Nutcracker. O manuseio terapêutico inclui tratamento conservador, cirurgia aberta, endovascular ou cauterização química. CONCLUSÃO: A síndrome de Nutcracker é rara, sendo que o conhecimento desta condição é fundamental para suspeita clínica acurada, diagnóstico precoce e manuseio terapêutico adequado.

BACKGROUND AND OBJECTIVES: Mesoaortic compression of the left renal vein, known as Nutcracker syndrome, causes renal venous hypertension and, consequently, the appearance of symptoms such as lower abdominal pain, varicocele and hematuria. The difficulty in the diagnosis may delay treatment, subject the patient to unnecessary procedures and complications of the venous compression. We report a case of a patient with hematuria treated at the Division of Nephrology in the Hospital de Clinicas de Porto Alegre - Universidade Federal do Rio Grande do Sul (Brazil). CASE REPORT: Male patient, 22 years of age, Caucasian, with complaints of pain in the lower abdominal, macroscopic hematuria and urinary obstruction, with basic investigation was inconclusive. Further investigation, after two years, revealed a nutcracker syndrome. Management can be conservative, open surgery, stent placement or intra-pelvic chemical cauterization. CONCLUSION: The Nutcracker syndrome is rare and the knowledge of this condition is the cornerstone to accurate diagnosis and proper management.

Repercussão da hemodiãlise na função pulmonar de pacientes com doença renal crônica terminal / Impact of hemodialysis on lung function in patients with chronic renal

Pacientes com doença renal desenvolvem frequentemente complicações pulmonares como edema, derrame pleural e infecção. Método: A avaliação respiratória deu-se através de exames de espirometria, manovacuometria, oximetria e gasometria, antes e depois de sessão de hemodiálise (HD). As variáveis espirométricas foram analisadas em porcentagens de valores de referencia com o objetivo de eliminar efeitos da idade, altura e sexo. Resultados e Discussão: Avaliaram-se 33 pacientes (51,5% mulheres) com média de idade 42,8 +- 14,2 anos, em tratamento no Hospital das Clínicas de Porto Alegre. A capacidade vital forçada (CVF), o volume expiratório forçado no primeiro segundo (VEF1) e o pico de fluxo expiratório (PFE) apresentaram um aumento significativo após sessão de HD, o que determinou um aumento no número de espirometrias normais, passando de 12 (36,4%) para 17 (51,5%). A força muscular também apresentou aumento significativo. A oximetria permaneceu inalterada após HD, o que pode ser explicado pelos resultados da gasometria, pois, após HD, houve um aumento substancial no PH e nos níveis de bicarbonato, caracterizando quadro de alcalose metabólica. Observou-se, também, queda na pressão parcial de oxigênio e aumento na pressão parcial de dióxido de carbono, provavelmente na tentativa de restabelecer o valor do PH. Conclusões: Mesmo sem apresentar sintomas respiratórios, pacientes renais crônicos apresentam alterações na função pulmonar que melhora após tratamento com HD.

Patients with kidney disease often develop complications such as pulmonary edema, pleural effusion, and infection. Method: The respiratory evaluation was made through examination of spirometry, manometer, pulse oximetry and blood gases before and after hemodialysis session (HD). Spirometric variables were analyzed as percentages of reference values ​​in order to eliminate the effects of age, gender and height. Results and Discussion: We evaluated 33 patients (51.5% women) with mean age 42.8 + - 14.2 years, treated at the Hospital das Clinicas de Porto Alegre. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1) and peak expiratory flow (PEF) showed a significant increase after HD session, which led to an increase in the number of normal spirometry results, from 12 ( 36.4%) to 17 (51.5%). Muscle strength also increased significantly. Pulse oximetry remained unchanged after HD, which can be explained by the results of blood gas analysis, since, after HD, there was a substantial increase in pH and bicarbonate levels, characterizing a condition of metabolic alkalosis. There was also a drop in partial pressure of oxygen and increased partial pressure of carbon dioxide, probably in an attempt to restore the value of PH. Conclusions: Even without respiratory symptoms, chronic renal failure patients show changes in lung function improves after treatment with HD.

Acute effect of simvastatin on inflammation and oxidative stress in chronic kidney disease.

BACKGROUND: Inflammation and oxidative stress (OS) are risk factors for cardiovascular disease in chronic kidney disease (CKD). This study assessed the acute effect of simvastatin on inflammatory and OS markers in stage 3 and 4 CKD patients. METHODS: Randomized, placebo-controlled, double-blind, cross-over study comprising 66 patients who were randomized to simvastatin (20 mg/day) or placebo for two 8-week periods. Glomerular filtration rate (GFR), lipid profile, C-reactive protein (CRP), fibrinogen, carbonyls and total radical-trapping antioxidant potential (TRAP) were measured. Interactions between potential confounding factors, such as diabetes mellitus, malnutrition, drug use, hypercholesterolemia and treatment response were assessed through the course of inflammatory and OS levels. RESULTS: Thirty-three patients were randomized to simvastatin/placebo (S-P), and 33 to placebo/simvastatin (P-S). Simvastatin significantly reduced total and LDL cholesterol (pretreatment vs. posttreatment: p=0.0001 and p=0.0001, respectively) in both periods. No differences were seen in CRP, fibrinogen, carbonyls and TRAP levels between S-P and P-S groups at the end of the 2 study periods. GFR was similar in both groups and negatively correlated to fibrinogen (r=-0.25, p=0.04) and TRAP (r=-0.27, p=0.03). No interactions were found between confounding factors and response to simvastatin. There was no interference of either a period effect or any carryover effect on study results. CONCLUSIONS: The use of simvastatin in CKD patients acutely did not reduce serum inflammation or OS markers. Possibly higher doses and/or longer treatment course of statin are required to produce drug pleiotropic effects in nondialysis CKD patients.

Quality of life and depressive symptoms in patients with major depression and end-stage renal disease: a matched-pair study.

OBJECTIVE: To compare the quality of life (QOL) and depressive symptoms of outpatients with major depression with that of nondepressed individuals undergoing hemodialysis (matched for age, gender, and ethnicity). METHODS: We used the WHOQOL BREF and the Beck Depression Inventory (BDI). RESULTS: After univariate analyses, depressed patients' QOL scores were significantly lower (P<.0001) in all the assessed domains (i.e., physical health, psychological, social relationships, environmental, and global QOL). Additionally, there was a significant difference in the severity of depression among the study groups (P<.0001). Finally, after multiple regression analysis, the QOL profile of depressed subjects remained significantly worse even when controlling for depression scores and diagnostic status. CONCLUSION: The subjective QOL of patients with major depression is significantly lower than that of subjects undergoing hemodialysis.

Prevalência da depressäo maior nos pacientes em hemodiálise crônica / Prevalence of major depression in patients on chronic hemodialysis

A depressão é uma condição prevalente e apresenta um impacto importante na evolução de pacientes com insuficiência renal crônica em estágio terminal. O presente estudo tem como objetivo primário estabelecer a prevalência de depressão maior nos pacientes em hemodiálise do HCPA. Como objetivos secundários, estão verificar a prevalência de alguns outros transtornos que compõem o chamado "espectro depressivo" e caracterizar os grupos de pacientes encontrados...

Avaliaçäo e manejo do paciente adulto com infecçäo urinária / Evaluation and management of adult urinary tract infections

Infecção urinária é uma das doenças mais comuns, sendo uma importante causa de morbidade em todas as idades. Estudos recentes têm ajudado a definir melhor as populações de risco para estas infecções, assim como as estratégias de manejo mais efetivas e de menor custo. A infecção urinária pode ser caracterizada como simples ou complicada. A apresentação da síndrome clínica e o tipo de hospedeiro ajudam o médico a determinar o diagnóstico e o manejo mais apropriado. Infecção urinária não complicada pode ser tratada empiricamente, sem necessidade de urocultura. Já bacteriúria assintomatica raramente requer tratamento medicamentoso. Casos de infecção complicada são diagnosticados por urocultura e necessitam uma terapia mais prolongada. Infecções urinárias em homens ocorrem com maior frequência após os 40 anos de idade e são muitas vezes associados com obstrução prostática