Recommendations from the Brazilian Society of Nephrology for approaching Covid-19 Diagnostic Testing in Dialysis Units.

The Covid-19 pandemic brought several challenges to the healthcare system: diagnosis, treatment and measures to prevent the spread of the disease. With the greater availability and variety of diagnostic tests, it is essential to properly interpret them. This paper intends to help dialysis units concerning the use of clinical criteria and diagnostic tests for decision making regarding the discontinuation of isolation of patients with suspected or confirmed Covid-19, as well as the return to work activities for employees with suspected or confirmed Covid-19.

Good Practice Recommendations from the Brazilian Society of Nephrology to Dialysis Units Concerning the Pandemic of the New Coronavirus (Covid-19).

Dialysis units are environments potentially prone to the spread of Covid-19. Patients cannot suspend treatment, and they often have comorbidities, which assigns them a higher risk and worse prognosis. The Brazilian Society of Nephrology prepared this document of good practices, whose technical recommendations deal with general measures that can be implemented to reduce the risk of transmission and prevent the spread of the disease in the unit.

Position statement from the Brazilian Society of Nephrology regarding chloroquine and hydroxychloroquine drug dose adjustment according to renal function.

Chloroquine and hydroxychloroquine have shown promising preliminary results and have been discussed as therapeutic options for patients with Covid-19. Despite the lack of robust evidence demonstrating the benefits and justifying the use of one of these drugs, the final decision is the responsibility of the attending physician and should be individualized and shared, whenever possible. This position statement recommends dosage adjustment for these drugs in the context of renal impairment.

Clinical outcomes of incident peritoneal dialysis patients coming from kidney transplantation program: A case-control study.

INTRODUCTION: Brazil ranks second in the absolute number of transplantations in the world. Despite improvements in graft survival, many patients will progress to graft loss and return to dialysis. Concerns exist regarding adverse clinical outcomes in this population when undergone peritoneal dialysis (PD). OBJECTIVE: To compare the occurrence of mortality, technique failure, and peritonitis among incident patients in PD coming from either Tx or pre-dialysis treatment. METHODOLOGY: A retrospective study in which 47 adult patients with Tx failure (Tx group) were matched for age, gender, diabetes mellitus (DM), modality and start year of PD, with 1:1 predialysis patient (nTx group). The Fine-Gray competing risk model was used to analyze mortality and technique failure. RESULTS: Compared to nTx, the Tx group had a lower body mass index, serum potassium, and albumin concentrations. A higher ferritin level, transferrin saturation and the number of patients with positive serology for viral hepatitis were also observed in the Tx group. In the multivariate analysis, patients of the Tx group had 4.4-times higher risk of death (p = 0.007), with infection as the main cause. Technique failure and peritonitis were similar in both groups. CONCLUSION: Previous Tx is a risk factor for mortality but not for technique failure or peritonitis in incident patients on a PD program.

Peritoneal Dialysis.

Peritoneal dialysis (PD) is a renal replacement therapy based on infusing a sterile solution into the peritoneal cavity through a catheter and provides for the removal of solutes and water using the peritoneal membrane as the exchange surface. This solution, which is in close contact with the capillaries in the peritoneum, allows diffusion solute transport and osmotic ultrafiltration water loss since it is hyperosmolar to plasma due to the addition of osmotic agents (most commonly glucose). Infusion and drainage of the solution into the peritoneal cavity can be performed in two ways: manually (continuous ambulatory PD), in which the patient usually goes through four solution changes throughout the day, or machine-assisted PD (automated PD), in which dialysis is performed with the aid of a cycling machine that allows changes to be made overnight while the patient is sleeping. Prescription and follow-up of PD involve characterizing the type of peritoneal transport and assessing the offered dialysis dose (solute clearance) as well as diagnosing and treating possible method-related complications (infectious and non-infectious).

Peritoneal Dialysis

SUMMARY Peritoneal dialysis (PD) is a renal replacement therapy based on infusing a sterile solution into the peritoneal cavity through a catheter and provides for the removal of solutes and water using the peritoneal membrane as the exchange surface. This solution, which is in close contact with the capillaries in the peritoneum, allows diffusion solute transport and osmotic ultrafiltration water loss since it is hyperosmolar to plasma due to the addition of osmotic agents (most commonly glucose). Infusion and drainage of the solution into the peritoneal cavity can be performed in two ways: manually (continuous ambulatory PD), in which the patient usually goes through four solution changes throughout the day, or machine-assisted PD (automated PD), in which dialysis is performed with the aid of a cycling machine that allows changes to be made overnight while the patient is sleeping. Prescription and follow-up of PD involve characterizing the type of peritoneal transport and assessing the offered dialysis dose (solute clearance) as well as diagnosing and treating possible method-related complications (infectious and non-infectious).

RESUMO A diálise peritoneal (DP) é uma terapia renal substitutiva baseada na infusão de uma solução estéril na cavidade peritoneal através de um cateter, proporcionando a remoção de solutos e água usando a membrana peritoneal como superfície de troca. Essa solução, em contato com os capilares do peritônio, permite o transporte difuso de solutos e a perda de água por ultrafiltração osmótica, uma vez que é hiperosmolar ao plasma devido à adição de agentes osmóticos (normalmente, a glicose). A infusão e drenagem da solução dentro da cavidade peritoneal pode ser realizada de duas maneiras: manualmente (DP ambulatorial contínua), em que o paciente, geralmente, passa por quatro trocas de solução durante o dia, ou por DP mecânica (automatizada), em que a diálise é realizada com o auxílio de uma máquina de diálise que permite que as trocas sejam feitas durante a noite, enquanto o paciente está dormindo. A prescrição e o acompanhamento da DP envolvem a caracterização do tipo de transporte peritoneal e a avaliação da dose de diálise oferecida (depuração do soluto), bem como o diagnóstico e tratamento de possíveis complicações relacionadas ao método (infecciosas e não infecciosas).

Position statement from the Brazilian Society of Nephrology regarding chloroquine and hydroxychloroquine drug dose adjustment according to renal function / Nota da Sociedade Brasileira de Nefrologia em relação ao ajuste das drogas cloroquina e hidroxicloroquina pela função renal

ABSTRACT Chloroquine and hydroxychloroquine have shown promising preliminary results and have been discussed as therapeutic options for patients with Covid-19. Despite the lack of robust evidence demonstrating the benefits and justifying the use of one of these drugs, the final decision is the responsibility of the attending physician and should be individualized and shared, whenever possible. This position statement recommends dosage adjustment for these drugs in the context of renal impairment.

RESUMO Em razão de resultados preliminares promissores, a hidroxicloroquina e a cloroquina têm sido discutidas como opção terapêutica para pacientes com Covid-19. Apesar da ausência de estudos robustos que evidenciem o benefício e justifiquem o uso de uma dessas drogas, a decisão final compete ao médico assistente, devendo ser individualizada e, sempre que possível, compartilhada. A presente nota pretende orientar o ajuste posológico dessas drogas no contexto da disfunção renal.

Recommendations from the Brazilian Society of Nephrology for approaching Covid-19 Diagnostic Testing in Dialysis Units / Recomendações da Sociedade Brasileira de Nefrologia para abordagem de exames diagnósticos da Covid-19 nas unidades de diálise

ABSTRACT The Covid-19 pandemic brought several challenges to the healthcare system: diagnosis, treatment and measures to prevent the spread of the disease. With the greater availability and variety of diagnostic tests, it is essential to properly interpret them. This paper intends to help dialysis units concerning the use of clinical criteria and diagnostic tests for decision making regarding the discontinuation of isolation of patients with suspected or confirmed Covid-19, as well as the return to work activities for employees with suspected or confirmed Covid-19.

RESUMO A pandemia da Covid-19 trouxe desafios ao sistema de saúde em diversas esferas: diagnóstico, tratamento e medidas para evitar a disseminação da doença. Com a maior disponibilização e variedades de testes diagnósticos, torna-se fundamental sua adequada interpretação. Este posicionamento pretende orientar unidades de diálise em relação ao uso de critérios clínicos e testes diagnósticos para a tomada de decisão referente à descontinuação do isolamento de pacientes com suspeita ou confirmação de Covid-19, assim como para o retorno às atividades laborais de colaboradores com suspeita ou confirmação de Covid-19.

Predictors of renal function recovery among patients undergoing renal replacement therapy following orthotopic liver transplantation.

Renal dysfunction frequently occurs during the periods preceding and following orthotopic liver transplantation (OLT), and in many cases, renal replacement therapy (RRT) is required. Information regarding the duration of RRT and the rate of kidney function recovery after OLT is crucial for transplant program management. We evaluated a sample of 155 stable patients undergoing post-intensive care hemodialysis (HD) from a patient population of 908 adults who underwent OLT. We investigated the average time to renal function recovery (duration of RRT required) and determined the risk factors for remaining on dialysis > 90 days after OLT. Log-rank tests were used for univariate analysis, and Cox proportional hazards models were used to identify factors associated with the risk of remaining on HD. The results of our analysis showed that of the 155 patients, 28% had pre-OLT diabetes mellitus, 21% had pre-OLT hypertension, and 40% had viral hepatitis. Among the patients, the median MELD (Model for End-Stage Liver Disease) score was 27 (interquartile range [IQR] 22-35). When they were listed for liver transplantation, 32% of the patients had serum creatinine (Scr) levels > 1.5 mg/dL or were on HD, and 50% had serum creatinine (Scr) levels > 1.5 mg/dL or were on HD at the time of OLT. Of the transplanted patients, 25% underwent pre-OLT intermittent HD, and 14% and 41% underwent continuous renal replacement therapy (CRRT) pre-OLT and post-OLT, respectively. At 90 days post-OLT, 118 (76%) patients had been taken off dialysis, and 16 (10%) patients had died while undergoing HD. The median recovery time of these post-OLT patients was 33 (IQR 27-39) days. In the multivariate analysis, fulminant hepatic failure as the cause of liver disease (p<0.001), the absence of pre-OLT hypertension (p = 0.016), a lower intraoperative fresh-frozen plasma (FFP) transfusion volume (p = 0.019) and not undergoing pre-OLT intermittent HD (p = 0.032) were associated with performing RRT for less than 90 days. Therefore, a high proportion of OLT patients showed improved renal function after OLT, and those who were diagnosed with fulminant hepatic failure, had no pre-OLT hypertension, received a lower transfused volume of intraoperative FFP and did not undergo pre-OLT intermittent HD had a higher probability of recovery.

Icodextrin reduces insulin resistance in non-diabetic patients undergoing automated peritoneal dialysis: results of a randomized controlled trial (STARCH).

BACKGROUND: Insulin resistance is a common risk factor in chronic kidney disease patients contributing to the high cardiovascular burden, even in the absence of diabetes. Glucose-based peritoneal dialysis (PD) solutions are thought to intensify insulin resistance due to the continuous glucose absorption from the peritoneal cavity. The aim of our study was to analyse the effect of the substitution of glucose for icodextrin on insulin resistance in non-diabetic PD patients in a multicentric randomized clinical trial. METHODS: This was a multicenter, open-label study with balanced randomization (1:1) and two parallel-groups. Inclusion criteria were non-diabetic adult patients on automated peritoneal dialysis (APD) for at least 3 months on therapy prior to randomization. Patients assigned to the intervention group were treated with 2L of icodextrin 7.5%, and the control group with glucose 2.5% during the long dwell and, at night in the cycler, with a prescription of standard glucose-based PD solution only in both groups. The primary end-point was the change in insulin resistance measured by homeostatic model assessment (HOMA) index at 90 days. RESULTS: Sixty patients were included in the intervention (n = 33) or the control (n = 27) groups. There was no difference between groups at baseline. After adjustment for pre-intervention HOMA index levels, the group treated with icodextrin had the lower post-intervention levels at 90 days in both intention to treat [1.49 (95% CI: 1.23-1.74) versus 1.89 (95% CI: 1.62-2.17)], (F = 4.643, P = 0.03, partial η(2) = 0.078); and the treated analysis [1.47 (95% CI: 1.01-1.84) versus 2.18 (95% CI: 1.81-2.55)], (F = 7.488, P = 0.01, partial η(2) = 0.195). CONCLUSIONS: The substitution of glucose for icodextrin for the long dwell improved insulin resistance measured by HOMA index in non-diabetic APD patients.

A new spectrophotometric method to detect residual amounts of peroxide after reprocessing hemodialysis filters / Um novo método espectrofotométrico para detectar níveis residuais de peróxido após o reprocessamento de filtros de hemodiálise

ABSTRACT Objective: Reuse of hemodialysis filters is a standard practice and the sterilizing chemical most often employed is peracetic acid. Before starting the dialysis session, filters and lines are checked for residual levels of peracetic acid by means of a non-quantitative colorimetric test that is visually interpreted. The objective of this study was to investigate a new quantitative spectrophotometric test for detection of peracetic acid residues. Methods: Peracetic acid solutions were prepared in concentrations ranging from 0.01 to 10 ppm. A reagent (potassium-titanium oxide + sulfuric acid) was added to each sample in proportions varying from 0.08 to 2.00 drops/mL of solution. Optical densities were determined in a spectrophotometer using a 405-nm filter and subjected to visual qualitative test by different observers. Results: A relation between peroxide concentrations and respective optical densities was observed and it was linear with R2 > 0.90 for all reagent/substrate proportions. The peak optical densities were obtained with the reagent/substrate ratio of 0.33 drops/mL, which was later standardized for all further experiments. Both qualitative and quantitative tests yielded a specificity of 100%. The quantitative test was more sensitive than the qualitative test and resulted in higher positive and negative predictive values. There was a difference between observers in the qualitative test and some samples with significant amounts of peroxide were not detected. Conclusion: A quantitative spectrophotometric test may improve detection of residues of peracetic acid when compared to the standard visual qualitative test. This innovation may contribute to the development of safer standards for reuse of hemodialysis filters.

RESUMO Objetivo: A reutilização de filtros de hemodiálise é uma prática disseminada e a substância química esterilizante mais empregada é o ácido peracético. Antes de iniciar a sessão de diálise, os filtros e as linhas são verificados em relação a níveis residuais de ácido peracético por meio de teste colorimétrico não quantitativo, com interpretação visual. O objetivo deste trabalho foi investigar um novo teste espectrofotométrico quantitativo para detecção de resíduos de ácido peracético. Métodos: As soluções de ácido peracético foram preparadas em concentrações que variam de 0,01 a 10 ppm. O reagente (óxido de potássio-titânio + ácido sulfúrico) foi acrescentado a cada amostra em proporções que variaram de 0,08 a 2,00 gotas/mL de solução. As densidades ópticas foram determinadas em um espectrofotômetro com filtro de 405 nm e submetidas a um teste visual qualitativo por diferentes observadores. Resultados: Observou-se a relação linear entre as concentrações de peróxido e as respectivas densidades ópticas com R2 > 0,90 para todas as proporções de reagente/substrato. As maiores densidades ópticas foram obtidas com a proporção reagente/substrato de 0,33 gotas/mL, que foi padronizada para todos os experimentos posteriores. Os testes qualitativos e quantitativos apresentaram especificidade de 100%. O teste quantitativo foi mais sensível do que o qualitativo e apresentou maiores valores preditivos positivos e negativos. Houve uma diferença entre os observadores no teste qualitativo e algumas amostras com quantidade significativa de peróxido não foram detectadas. Conclusão: O teste espectrofotométrico quantitativo pode melhorar a detecção de resíduos de ácido peracético em comparação ao teste visual qualitativo padrão. Essa inovação pode contribuir para o desenvolvimento de padrões mais seguros na reutilização de filtros de hemodiálise.

A new spectrophotometric method to detect residual amounts of peroxide after reprocessing hemodialysis filters.

OBJECTIVE: Reuse of hemodialysis filters is a standard practice and the sterilizing chemical most often employed is peracetic acid. Before starting the dialysis session, filters and lines are checked for residual levels of peracetic acid by means of a non-quantitative colorimetric test that is visually interpreted. The objective of this study was to investigate a new quantitative spectrophotometric test for detection of peracetic acid residues. METHODS: Peracetic acid solutions were prepared in concentrations ranging from 0.01 to 10 ppm. A reagent (potassium-titanium oxide + sulfuric acid) was added to each sample in proportions varying from 0.08 to 2.00 drops/mL of solution. Optical densities were determined in a spectrophotometer using a 405-nm filter and subjected to visual qualitative test by different observers. RESULTS: A relation between peroxide concentrations and respective optical densities was observed and it was linear with R2 > 0.90 for all reagent/substrate proportions. The peak optical densities were obtained with the reagent/substrate ratio of 0.33 drops/mL, which was later standardized for all further experiments. Both qualitative and quantitative tests yielded a specificity of 100%. The quantitative test was more sensitive than the qualitative test and resulted in higher positive and negative predictive values. There was a difference between observers in the qualitative test and some samples with significant amounts of peroxide were not detected. CONCLUSION: A quantitative spectrophotometric test may improve detection of residues of peracetic acid when compared to the standard visual qualitative test. This innovation may contribute to the development of safer standards for reuse of hemodialysis filters.

Tratamento MARS (Molecular Adsorbent Recirculating System) em pacientes com cirrose biliar primária: relato da primeira expectativa ambulatorial no Brasil / The MARS (Molecular Adsorbent Recirculating System): patient with primary biliary cirrhosis: first experience report in Brazil

O tratamento MARS (Molecular Adsorbent Recirculating System) permite a remoção de toxinas hepáticas ligadas à albumina. Dentre estas substâncias estão os ácidos biliares, que têm importante papel no prurido nas síndromes colestáticas. Relato do Caso: Descrição da primeira experiência brasileira ambulatorial de diálise MARS em paciente de 39 anos, sexo feminino, com diagnóstico de cirrose biliar primária e prurido recorrente após transplante de fígado e refratário às medidas clínicas, havendo também importante comprometimento na qualidade de vida. Após a realização de 2 sessões consecutivas do tratamento MARS, houve controle do prurido por pelo menos 7 meses. Procedimento bem tolerado e sem intercorrências Conclusão: O tratamento MARS é uma opção para pacientes com prurido intratável secundário a síndromes colestáticas e está associado à reduzida taxa de complicações

Effects of uraemia and dialysis modality on polymorphonuclear cell apoptosis and function.

BACKGROUND: Previous studies have reported that incubation of polymorphonuclear cells (PMN) in uraemic plasma or with different haemodialysis membranes and peritoneal dialysis solutions increases apoptosis in this cell type. In addition, PMN harvested from uraemic patients show a reduced ability to generate superoxide in response to stimuli as well as impaired phagocytosis, chemotaxis and degranulation. The aim of the current study was to investigate the effect of uraemia and dialysis modality on apoptosis and function in freshly harvested non-incubated PMN. METHODS: Polymorphonuclear cells were harvested from 14 chronic haemodialysis (HD) patients, from 14 continuous peritoneal dialysis patients (CAPD), 28 chronic kidney disease (CKD), pre-dialysis patients and from 14 healthy subjects (Controls). In these in vivo experiments, PMN apoptosis was studied by means of flow cytometric analysis of annexin V binding to freshly isolated cells. Polymorphonuclear cell phagocytosis and production of reactive oxygen species by unstimulated or stimulated (S.aureus, fMLP, PMA) cells were also studied by flow cytometry using whole blood. RESULTS: We observed increased PMN apoptosis in CKD patients. CAPD and HD patients displayed PMN apoptosis rates similar to controls. In the HD group, PMN exhibited decreased phagocytosis rates. In contrast, phagocytosis rates in PMN from CAPD were not significantly different from controls. In the CKD and HD groups, apoptosis was inversely correlated with respiratory burst activity and phagocytosis. CONCLUSION: Our results suggest that both uraemia and treatment modality may interfere with PMN apoptosis and function. Dialysis appears to normalize the increased PMN apoptosis rates observed in CKD patients.

Efeito da biocompatibilidade de membranas na fagocitose, metabolismo oxidativo e síntese de citocinas de células mononucleares de snague periférico de pacientes em hemodiálise / Impact of dialuzer membrane on phagocytosis, oxidative stress and cytokine synthesis by peripheral blood mononuclear cells in hemodialysis patients

As interações entre o sangue e a membrana do dialisador durante a hemodiálise (HD) desencadeiam respostas inflamatórias, especialmente com o uso de membranas de cuprofane. Nos últimos anos, as membranas de cuprofane vêm sendo substituídas pelas membranas de celulose substituída e pelas membranas sintéticas em muitos centros de diálise no mundo. Portanto, o objetivo desta pesquisa foi comparar o efeito in vivo da HD com membrana de celulose substituída com a HD com membrana sintética na ativação de complemento, nas funções de células mononucleares de sangue periférico (CMSP) e na síntese de citocinas. Em um estudo do tipo crossover, comparou¬-se o efeito de uma membrana de celulose substituída - acetato de celulose (CA) com uma membrana sintética - polissulfona (PS) em relação a fagocitose e metabolismo oxidativo de CMSP, níveis séricos e síntese de fator de necrose tumoral alfa (TNF-a) e Interleucina-10 (IL-10) por CMSP e níveis séricos de C3a e do complexo terminal do complemento (TCC). Vinte pacientes em HD crônica foram incluídos no estudo, de maneira alternada, em 2 grupos: um tratado com dialisador de CA e outro com PS, ambos de baixo-fluxo. Após 2 semanas, os pacientes trocaram de dialisador (CA por PS, ou vice-versa), e foram dialisados por mais 2 semanas. As respostas celulares foram medidas no início do estudo e ao final de cada período do mesmo. A fagocitose e a produção de peróxido de hidrogênio espontânea e estimulada por S. aureus, fMLP, PMA e LPS de CMSP foram estudadas por citometria de fluxo em amostras de sangue total. As CMSP foram isoladas de amostras de sangue e incubadas por 24 horas com ou sem LPS para avaliação da síntese de citocinas. Não foram encontradas diferenças entre as membranas em relação a fagocitose, produção de peróxido de hidrogênio e síntese de citocinas por CMSP ou nos níveis séricos de citocinas, C3a e TCC. Entretanto, após HD, os níveis de complemento correlacionaram-se negativamente com a síntese de...