Relationship of hemoglobin levels with outcomes in deceased donor kidney transplant: a retrospective cohort study / Relação dos níveis de hemoglobina com desfechos em transplante renal de doador falecido: um estudo de coorte retrospectivo

ABSTRACT Introduction: Anemia is frequent in patients undergoing replacement therapy for kidney failure. Anemia in the pre- and post-transplantation period might be related to kidney transplant outcomes. The current study therefore sought to assess the relationship between anemia, delayed allograft function (DGF), chronic kidney allograft dysfunction (CAD), and death from any cause following kidney transplantation from a deceased donor. Methods: This was a retrospective study with 206 kidney transplant patients of deceased donors. We analyzed deceased donors' and kidney transplant patients' demographic data. Moreover, we compared biochemical parameters, anemia status, and medicines between DGF and non-DGF groups. Afterward, we performed a multivariate analysis. We also evaluated outcomes, such as CAD within one year and death in ten years. Results: We observed a lower frequency of pre-transplant hemoglobin concentration (Hb) but higher frequency of donor-serum creatinine and red blood transfusion within one week after transplantation in the group with DGF. In addition, there was an independent association between Hb concentration before transplantation and DGF [OR 0.252, 95%CI: 0.159-0.401; p < 0.001]. There was also an association between Hb concentration after six months of kidney transplantation and both CAD [OR 0.798, 95% CI: 0.687-0.926; p = 0.003] and death from any cause. Conclusion: An association was found between pre-transplantation anemia and DGF and between anemia six months after transplantation and both CAD and death by any cause. Thus, anemia before or after transplantation affects the outcomes for patients who have undergone kidney transplantation from a deceased donor.

RESUMO Introdução: A anemia é frequente em pacientes submetidos à terapia substitutiva para insuficiência renal. A anemia nos períodos pré e pós-transplante pode estar relacionada aos desfechos do transplante renal. Portanto, o presente estudo buscou avaliar a relação entre anemia, função retardada do enxerto (FRE), disfunção crônica do enxerto renal (DCE) e óbito por qualquer causa após transplante renal de doador falecido. Métodos: Este foi um estudo retrospectivo com 206 pacientes transplantados renais de doadores falecidos. Analisamos dados demográficos de doadores falecidos e pacientes transplantados renais. Além disso, comparamos parâmetros bioquímicos, status de anemia e medicamentos entre os grupos FRE e não-FRE. Posteriormente, realizamos uma análise multivariada. Também avaliamos desfechos, como DCE em um ano e óbito em dez anos. Resultados: Observamos menor frequência de concentração de hemoglobina (Hb) pré-transplante, mas maior frequência de creatinina sérica do doador e transfusão de hemácias no período de uma semana após o transplante no grupo FRE. Além disso, houve associação independente entre a concentração de Hb antes do transplante e a FRE [OR 0,252; IC 95%: 0,159-0,401; p < 0,001]. Houve também associação entre a concentração de Hb após seis meses de transplante renal e ambos, DCE [OR 0,798; IC95%: 0,687-0,926; p = 0,003] e óbito por qualquer causa. Conclusão: Encontrou-se uma associação entre anemia pré-transplante e FRE e entre anemia seis meses após o transplante e ambos, DCE e óbito por qualquer causa. Assim, a anemia antes ou após o transplante afeta os desfechos de pacientes que foram submetidos a transplante renal de doador falecido.

Acute kidney injury outcomes in covid-19 patients: systematic review and meta-analysis / Desfechos de lesão renal aguda em pacientes com covid-19: revisão sistemática e metanálise

Abstract Background: Acute kidney injury (AKI) is a frequent complication of coronavirus-19 disease (COVID-19). Therefore, we decided to perform a systematic review and meta-analysis with data from the literature to relate the development of COVID-19 associated-AKI with comorbidities, medications, and the impact of mechanical ventilation. Methods: We performed a systematic review using the Newcastle-Ottawa scale and a meta-analysis using the R program. Relevant studies were searched in the PubMed, Medline, and SciELO electronic databases. Search filters were used to include reports after 2020 and cohort studies. Results: In total, 1166 articles were identified and 55 English-written articles were included based on the risk of bias. Of all COVID-19-hospitalized patients presenting with AKI (n = 18029) classified as Kidney Disease Improving Global Outcomes stage 1 to 3, approximately 18% required mechanical ventilation and 39.2 % died. Around 11.3% of the patients required kidney replacement therapy (KRT) and of these, 1093 died and 321 required continuous KRT. Death is more frequent in individuals with AKI [OR 6.03, 95%CI: 5.73-6.74; p<0.01]. Finally, mechanical ventilation is an aggravating factor in the clinical conditions studied [OR 11.01, 95%CI: 10.29-11.77; p<0.01]. Conclusion: Current literature indicates AKI as an important complication in COVID-19. In this context, we observed that comorbidities, such as chronic kidney disease and heart failure, were more related to the development of AKI. In addition, mechanical ventilation was seen as an aggravating factor in this scenario.

Resumo Antecedentes: Lesão renal aguda (LRA) é uma complicação frequente da doença do coronavírus-19 (COVID-19). Desta forma, decidimos realizar uma revisão sistemática e uma metanálise com dados da literatura para relacionar o desenvolvimento de LRA associada à COVID-19 com comorbidades, medicamentos e o impacto da ventilação mecânica. Métodos: Realizamos uma revisão sistemática usando a escala de Newcastle-Ottawa e uma metanálise utilizando o programa R. Estudos relevantes foram pesquisados nos bancos de dados eletrônicos PubMed, Medline e SciELO. Foram utilizados filtros de pesquisa para incluir relatos após 2020 e estudos de coorte. Resultados: No total, foram identificados 1166 artigos, e foram incluídos 55 artigos escritos em língua inglesa com base no risco de viés. De todos os pacientes hospitalizados por COVID-19 apresentando LRA (n = 18029) classificados como Kidney Disease Improving Global Outcomes estágios 1 a 3, aproximadamente 18% necessitaram de ventilação mecânica e 39,2% foram a óbito. Cerca de 11,3% dos pacientes necessitaram de terapia renal substitutiva (TRS) e destes, 1093 foram a óbito e 321 necessitaram de TRS contínua. O óbito é mais frequente em indivíduos com LRA [OR 6,03; IC95%: 5,73-6,74; p<0,01]. Por fim, a ventilação mecânica é um fator agravante nas condições clínicas estudadas [OR 11,01; IC95%: 10,29-11,77; p<0,01]. Conclusão: A literatura atual indica a LRA como uma complicação importante na COVID-19. Neste contexto, observamos que comorbidades, como doença renal crônica e insuficiência cardíaca, estiveram mais relacionadas ao desenvolvimento de LRA. Além disso, a ventilação mecânica foi vista como um fator agravante neste cenário.

Relation between red blood cell distribution width and acute kidney injury in patients with sepsis

ABSTRACT Objective The objective of the present study is to evaluate the association of red blood cell distribution width with acute kidney injury in sepsis. Methods This is a retrospective study of 849 critically ill patients with sepsis in intensive care unit. Demographic data, renal function, inflammation, complete blood count, and acid-base parameters were compared between acute kidney injury and non-acute kidney injury groups. Therefore, a multivariate analysis was performed to observe independent predictive factors. Results Comparatively, higher levels of C-reactive protein, lactate, red blood cell distribution width, and Simplified Acute Physiology Score 3 were found in the acute kidney injury group. The study showed a higher frequency of women, hemoglobin (Hgb) concentration, platelets, bicarbonate and PaO2/FiO2 ratio in the non-acute kidney injury group. In addition, there was an independent association of comorbidity-chronic kidney disease [OR 3.549, 95%CI: 1.627-7.743; p<0.001], urea [OR 1.047, 95%CI: 1.036-1.058; p<0.001] and RDW [OR 1.158, 95%CI: 1.045-1.283; p=0.005] with acute kidney injury in sepsis patients. Conclusion As an elective risk factor, red blood cell distribution width was independently associated with sepsis-related acute kidney injury. Thus, red blood cell distribution width acts like a predictive factor for sepsis-induced acute kidney injury in intensive care unit admission.

Hypertonic saline and pentoxifylline enhance survival, reducing apoptosis and oxidative stress in a rat model of strangulated closed loop small bowel obstruction

OBJECTIVES: Intestinal obstruction has a high mortality rate when therapeutic treatment is delayed. Resuscitation in intestinal obstruction requires a large volume of fluid, and fluid combinations have been studied. Therefore, we evaluated the effects of hypertonic saline solution (HS) with pentoxifylline (PTX) on apoptosis, oxidative stress and survival rate. METHODS: Wistar rats were subjected to intestinal obstruction and ischemia through a closed loop ligation of the terminal ileum and its vessels. After 24 hours, the necrotic bowel segment was resected, and the animals were randomized into four groups according to the following resuscitation strategies: Ringer's lactate solution (RL) (RL-32 ml/kg); RL+PTX (25 mg/kg); HS+PTX (HS, 7.5%, 4 ml/kg), and no resuscitation (IO-intestinal obstruction and ischemia). Euthanasia was performed 3 hours after resuscitation to obtain kidney and intestine samples. A malondialdehyde (MDA) assay was performed to evaluate oxidative stress, and histochemical analyses (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling [TUNEL], Bcl-2 and Bax) were conducted to evaluate kidney apoptosis. Survival was analyzed with another series of animals that were observed for 15 days. RESULTS: PTX in combination with RL or HS reduced the MDA levels (nmol/mg of protein), as follows: kidney IO=0.42; RL=0.49; RL+PTX=0.31; HS+PTX=0.34 (p<0.05); intestine: IO=0.42; RL=0.48; RL+PTX=0.29; HS+PTX=0.26 (p<0.05). The number of labeled cells for TUNEL and Bax was lower in the HS+PTX group than in the other groups (p<0.05). The Bax/Bcl-2 ratio was lower in the HS+PTX group than in the other groups (p<0.05). The survival rate on the 15th day was higher in the HS+PTX group (77%) than in the RL+PTX group (11%). CONCLUSION: PTX in combination with HS enhanced survival and attenuated oxidative stress and apoptosis. However, when combined with RL, PTX did not reduce apoptosis or mortality.

Intraocular pressure and ocular perfusion during hemodialysis / Pressão intraocular e perfusão ocular durante hemodiálise

AIM: To evaluate the intraocular pressure and ocular perfusion pressure during a hemodialysis. METHODS: Sixty-seven eyes from thirty-five patients were evaluated at the beggining of hemodialysis, 2 hours and 4 hours after initiation. Intraocular pressure was evaluated using a Tonopen. Systolic and diastolic arterial pressures were measured with a manual sphygmomanometer. The ocular perfusion pressure was estimated by mea suring the difference between 2/3 of the mean arterial pressure and the intraocular pressure values. Generalized estimating equations were used to evaluate the difference between the repeated measurements using the appropriate correction for inter-eye dependency. RESULTS: There was no statistically significant difference in ocular perfusion pressure, in intraocular pressure (p=0.93) and in systolic arterial pressure (p=0.92) at the three time points (p=0.69). But, when analyzing the extreme values, some patients exhibited lower diastolic perfusion pressures at all time points. CONCLUSION: Our results did not support the view that significant changes in ocular perfusion pressure and intraocular pressure occur during hemodialysis session. However, we observed that some patients exhibited lower diastolic perfusion pressures, which could be a poor prognostic factor for glaucoma patients.

OBJETIVO: Avaliar a pressão intraocular e a pressão de perfusão ocular durante uma sessão de hemodiálise. MÉTODOS: Sessenta e sete olhos de trinta e cinco pacientes foram avaliados no início, após 2 horas e após 4 horas do início de uma sessão de hemodiálise. A pressão intraocular foi avaliada usando o aparelho Tonopen. Pressões arteriais sistólica e diastólica foram aferidas usando esfigmomanômetro manual. A pressão de perfusão ocular foi estimada por meio do cálculo da diferença entre 2/3 da pressão arterial média e valores da pressão intraocular. Equações de estimação generalizada foram usadas para avaliar a diferença entre medidas repetidas usando correção apropriada para dependência entres olhos. RESULTADOS: Não houve diferença estatisticamente significativa na pressão de perfusão ocular, PIO (p=0,93) e na pressão arterial sistólica (p=0,92) nos três períodos medidos da hemodiálise (p=0,69). Mas, quando analisados valores extremos, alguns pacientes exibiram pressões diastólicas menores em todos os períodos aferidos. CONCLUSÃO: Nossos resultados não apontaram mudanças significativas na pressão de perfusão ocular e pressão intraocular durante a hemodiálise. No entanto, foi observado que alguns pacientes exibiram pressões diastólicas menores, o que pode ser um fator de prognóstico ruim para pacientes com glaucoma.

Divergences in antihypertensive therapy in special situations in nephrology

CONTEXT AND OBJECTIVE: The choice of an antihypertensive drug is based on several criteria and specific situations give rise to doubt and controversy. The aim here was to evaluate physicians’ approaches towards treatment with antihypertensive agents in specific situations. DESIGN AND SETTING: Cross-sectional study, at Universidade Federal de São Paulo, São Paulo. METHODS: A questionnaire was applied during a nephrology meeting to evaluate individual approaches towards each hypothetical clinical situation. The questionnaire consisted of five multiple-choice questions (clinical cases) concerning controversial aspects of antihypertensive therapy. RESULTS: A total of 165 questionnaires were analyzed. Most participants were nephrologists (93.2 percent). There was a preference for angiotensin-converting enzyme (ACE) inhibitors in at least two of the cases. Only 57.2 percent of the physicians were correct in choosing beta-blockers as the first-line drugs for patients with ischemic coronary disease. Moreover, 66.2 percent chose ACE inhibitors as the first-line drugs for patients with chronic kidney disease and proteinuria. About 5 percent of the physicians did not follow the current recommendations for the use of ACE inhibitors in diabetic patients with microalbuminuria. The most controversial question concerned the first-line drug for advanced chronic kidney disease. Most physicians were correct in choosing calcium channel blockers and avoiding ACE inhibitors in renovascular hypertension in the case of a patient with a single functioning kidney. CONCLUSIONS: Most physicians adopted the correct approach, but some had an alternative strategy for the same situations that was not based on evidence.

CONTEXTO E OBJETIVO: A escolha da droga anti-hipertensiva depende de diversos fatores. Determinadas situações geram dúvida e discordância entre médicos. O objetivo foi avaliar a conduta de nefrologistas e clínicos em situações hipotéticas relacionadas ao tratamento da hipertensão. TIPO DE ESTUDO E LOCAL: Estudo transversal, na Universidade Federal de São Paulo, São Paulo, Brasil. MÉTODO: Foi aplicado um questionário com cinco casos clínicos hipotéticos durante o X Encontro Paulista de Nefrologia, com o objetivo de avaliar a primeira escolha de droga anti-hipertensiva em cada situação, contemplando as principais dúvidas relacionadas. RESULTADOS: Foram analisados 165 questionários. A maior parte dos médicos era composta por nefrologistas (93,2 por cento). Houve preferência pelo uso dos inibidores da enzima conversora de angiotensina (IECA) em dois dos cinco casos. Apenas 57,2 por cento acertaram na escolha do beta-bloqueador como primeira opção nos pacientes com coronariopatia. Além disso, 66,2 por cento optaram por IECA como drogas de eleição em renais crônicos com proteinúria. Aproximadamente 5 por cento dos colegas não seguiram as recomendações quanto ao uso dos IECA ou ARA em diabéticos com microalbuminúria. A questão com mais divergências foi a que avaliou a droga de escolha na doença renal crônica em fase avançada. A maior parte dos médicos acertou ao evitar o uso dos IECA na hipertensão renovascular em pacientes com rim único funcionante. CONCLUSÕES: A maior parte dos colegas adota condutas coerentes com os consensos relacionados à hipertensão arterial e doença renal, contudo, uma parcela não desprezível diverge e adota condutas não recomendadas.