Longitudinal changes in nutritional parameters and resting energy expenditure in end-stage renal disease / Alterações longitudinais nos parâmetros nutricionais e gasto energético de repouso na doença renal em estágio terminal

Abstract Aims: To evaluate the nutritional status, resting energy expenditure, caloric and protein intake, and evolution of biochemical parameters in three stages of chronic kidney disease: pre-dialytic, at the beginning of the dialysis treatment, and 30 days after starting treatment. Methods: The chi-square and Student's t tests were used to compare the variables, and analysis of repeated measurements was used to compare the data obtained in the three moments evaluated. The results were discussed at the 5% level of significance. Results: We evaluated 35 patients, 60% female and 60% with diabetes mellitus. There was a decrease in midarm circumference and serum albumin. Inflammatory state and caloric and protein intake increased. There was no significant difference in resting energy expenditure in the three moments. The serum urea and serum albumin, handgrip strength, and protein consumption after 30 days from the start of dialysis were greater in the peritoneal dialysis patients, when compared to the hemodialysis population. Conclusion: there was a decrease in midarm circumference and serum albumin and an increase in protein intake after dialysis. The peritoneal dialysis patients had higher muscle strength, even with lower protein intake. Resting energy expenditure was not different between dialysis methods and the moments evaluated.

Resumo Objetivos: Avaliar o estado nutricional, o gasto energético em repouso, o gasto calórico e proteico e a evolução dos parâmetros bioquímicos em três estágios da doença renal crônica: pré-dialítico, no início do tratamento dialítico e 30 dias após o início do tratamento. Métodos: O teste do qui-quadrado e o teste t de Student foram utilizados para comparar as variáveis, e a análise das medidas repetidas foi utilizada para comparar os dados obtidos nos três momentos avaliados. Os resultados foram discutidos ao nível de significância de 5%. Resultados: Foram avaliados 35 pacientes, 60% mulheres e 60% com diabetes mellitus. Houve uma diminuição na circunferência do terço médio do braço (CMB) e na albumina sérica. O estado inflamatório e a ingestão calórica e protéica aumentaram. Não houve diferença significativa no gasto energético em repouso nos três momentos. A ureia sérica e a albumina sérica, a força de preensão manual e o consumo de proteínas após 30 dias do início da diálise foram maiores nos pacientes em diálise peritoneal, quando comparados com a população em hemodiálise. Conclusão: houve diminuição da circunferência do terço médio do braço e na albumina sérica, e aumento da ingestão protéica após a diálise. Os pacientes em diálise peritoneal apresentaram maior força muscular, mesmo com menor consumo proteico. O gasto energético em repouso não foi diferente entre os métodos de diálise e os momentos avaliados.

Longitudinal changes in nutritional parameters and resting energy expenditure in end-stage renal disease.

AIMS: To evaluate the nutritional status, resting energy expenditure, caloric and protein intake, and evolution of biochemical parameters in three stages of chronic kidney disease: pre-dialytic, at the beginning of the dialysis treatment, and 30 days after starting treatment. METHODS: The chi-square and Student's t tests were used to compare the variables, and analysis of repeated measurements was used to compare the data obtained in the three moments evaluated. The results were discussed at the 5% level of significance. RESULTS: We evaluated 35 patients, 60% female and 60% with diabetes mellitus. There was a decrease in midarm circumference and serum albumin. Inflammatory state and caloric and protein intake increased. There was no significant difference in resting energy expenditure in the three moments. The serum urea and serum albumin, handgrip strength, and protein consumption after 30 days from the start of dialysis were greater in the peritoneal dialysis patients, when compared to the hemodialysis population. CONCLUSION: there was a decrease in midarm circumference and serum albumin and an increase in protein intake after dialysis. The peritoneal dialysis patients had higher muscle strength, even with lower protein intake. Resting energy expenditure was not different between dialysis methods and the moments evaluated.

Poor agreement between indirect calorimetry and predictive formula of rest energy expenditure in pre-dialytic and dialytic chronic kidney disease.

BACKGROUND/AIMS: Protein-energy wasting (PEW) is common in the end-stage of chronic kidney disease (CKD) and can be caused by factors related to poor dietary intake and changes in energy expenditure. Indirect calorimetry (IC) is the gold standard method to measure resting energy expenditure (REE), however, it is not much available and it is common to use predictive formulas of REE in clinical practice. This study compared the values of REE measured by IC to those estimated by Harris & Benedict formula, the most one used in clinical practice in Brazil. METHODS: Patients with stage 5 CKD (an estimated glomerular filtration rate <15 mL/min/1.73 m2), >18 years old were included and submitted to the IC test and Harris & Benedict's predictive formula. The assessments were performed at three moments: pre-dialysis indications (P1), at the beginning of dialysis indication (P2) and 30 days after the start of dialysis therapy (P3). Tuckey's test was used to compare energy expenditure variable by groups, and the Bland & Altman analysis was used to compare the agreement between the methods. A significance level of p < 0.05 and agreement limits of up to 200 Kcal were used. RESULTS: Thirty-five patients with mean age of 61.2 ± 10.9 years were included, 60% female, 17% afrodescendants and 60% with diabetes mellitus. There were no significant differences in REE between the three moments (P1: 1289.8 ± 382.7 kcal, P2: 1218.2 ± 362.8 kcal, P3: 1269.5 ± 335.1 kcal, p = 0.874). Harris & Benedict formula did not show IC agreement for the REE measurement because it presented high limits of agreement or because of the low precision of the estimated measure. CONCLUSION: This study showed that there was no significant alteration of REE by IC and that REE values estimated by Harris & Benedict formula did not agree with the values measured by IC in this population. The role of Harris & Benedict formula should be re-evaluated in stage 5 CKD patients.

Daily variability of resting energy expenditure in acute kidney injury patients on dialysis.

INTRODUCTION: It is needed for nutrition prescription correct estimate of resting energy expenditure (REE), which is a challenge given the possible daily variation in critically ill patients with acute kidney injury (AKI). OBJECTIVE: To evaluate the daily variability of REE measured by indirect calorimetry (IC) in patients with AKI and dialysis indication and identify clinical variables associated with REE. METHODS: The REE was measured on the time of dialysis indication and the subsequent four days. We also evaluated parameters that can influence the REE. The daily differences were analyzed by generalized linear model for repeated measures. We also used Spearman correlation and multiple linear regression. RESULTS: There were 301 IC measurements in 114 patients, mean age of 60.65 ± 16.9 years and 68.4% were male. The average REE was 2081 ± 645 kcal, rising on day 5 (2270 ± 556 kcal) compared to the days 2 and 3 (2022 ± 754; 2022 ± 660 kcal, respectively, p = 0,04). When normalized to weight, there was no significant difference in REE (kcal/kg/day) during follow-up. REE was positively correlated with total leukocyte count, C-reactive protein, minute volume (MV), fraction of inspired oxygen (FiO2) urea nitrogen appearance (UNA), weight and height and inversely with age. After multiple regression, MV, FiO2, weight and age are correlated independently with REE. CONCLUSION: Patients with AKI have REE stable. The REE was associated independently with FiO2, MV, body weight and age. Thus, ventilatory parameters should be evaluated each day for the necessary dietary changes may be made.

Daily variability of resting energy expenditure in acute kidney injury patients on dialysis / Variabilidade diária do gasto energético de repouso em pacientes com lesão renal aguda em tratamento dialítico

Abstract Introduction: It is needed for nutrition prescription correct estimate of resting energy expenditure (REE), which is a challenge given the possible daily variation in critically ill patients with acute kidney injury (AKI). Objective: To evaluate the daily variability of REE measured by indirect calorimetry (IC) in patients with AKI and dialysis indication and identify clinical variables associated with REE. Methods: The REE was measured on the time of dialysis indication and the subsequent four days. We also evaluated parameters that can influence the REE. The daily differences were analyzed by generalized linear model for repeated measures. We also used Spearman correlation and multiple linear regression. Results: There were 301 IC measurements in 114 patients, mean age of 60.65 ± 16.9 years and 68.4% were male. The average REE was 2081 ± 645 kcal, rising on day 5 (2270 ± 556 kcal) compared to the days 2 and 3 (2022 ± 754; 2022 ± 660 kcal, respectively, p = 0,04). When normalized to weight, there was no significant difference in REE (kcal/kg/day) during follow-up. REE was positively correlated with total leukocyte count, C-reactive protein, minute volume (MV), fraction of inspired oxygen (FiO2) urea nitrogen appearance (UNA), weight and height and inversely with age. After multiple regression, MV, FiO2, weight and age are correlated independently with REE. Conclusion: Patients with AKI have REE stable. The REE was associated independently with FiO2, MV, body weight and age. Thus, ventilatory parameters should be evaluated each day for the necessary dietary changes may be made.

Resumo Introdução: É imprescindível a correta estimativa do gasto energético de repouso (GER), que pode apresentar considerável variação diária no paciente crítico com lesão renal aguda (LRA). Objetivo: Avaliar a variabilidade diária do GER medido por calorimetria indireta (CI) em pacientes com LRA e indicação dialítica e identificar as variáveis clínicas associadas ao GER. Métodos: O GER foi medido no dia da indicação do procedimento dialítico e nos quatro dias subsequentes. Também foram avaliados parâmetros que podem influenciar o GER. As diferenças diárias foram analisadas pelo modelo linear generalizado para medidas repetidas, com distribuição gama, além da correlação de Spearman e regressão linear múltipla. Resultados: Foram 301 medidas de CI realizadas em 114 pacientes, com idade de 60,65 ± 16,9 anos e 68,4% do sexo masculino. O GER médio foi de 2081 ± 645 Kcal, com aumento no dia 5 (2270 ± 556 Kcal), quando comparado aos dias 2 e 3 (2022 ± 754; 2022 ± 660 kcal, respectivamente, p = 0,04); quando normalizado para peso, não houve diferença significante no GER (kcal/kg/dia) durante o acompanhamento. GER correlacionou-se positivamente com temperatura corporal, contagem total de leucócitos, proteína C reativa, volume minuto (VM), fração inspirada de oxigênio (FiO2), aparecimento de nitrogênio ureico (UNA), peso corporal e estatura e inversamente com idade. Após a regressão linear múltipla, somente VM, FiO2 e peso corporal e idade se correlacionaram independentemente. Conclusão: Pacientes com LRA dialíticos apresentam GER estável. O GER foi associado independentemente com FiO2, VM, peso e idade. Assim, requisitos ventilatórios precisam ser avaliados diariamente para que alterações necessárias na prescrição dietética sejam feitas.

Peritoneal Dialysis Treatment Modality Option in Acute Kidney Injury.

BACKGROUND: Peritoneal dialysis (PD) may be a feasible and safe alternative to haemodialysis not only in the chronic but also in the acute setting. It was previously widely accepted as a modality for acute kidney injury (AKI) treatment, but its practice declined in favor of other types of extracorporeal therapies. SUMMARY: The interest in PD to manage AKI patients has been increased and PD is now frequently used in developing countries because of its lower cost and minimal infrastructural requirements. Studies from these countries have shown that, with careful thought and planning, critically ill patients can be successfully treated using PD. Some of the classic limitations of PD use in AKI, such as infectious and mechanical complications and poor metabolic control, have been decreased with the use of cyclers, flexible catheters, and a high volume of dialysate. The recent publication of the International Society of Peritoneal Dialysis guidelines for PD in AKI has tried to address these issues and provide an evidence-based standard by which to initiate therapy. Key Message: In this review, advances in technical aspects and the advantages and limitations of PD were discussed; it clearly showed that PD is a simple, safe, and efficient way to correct metabolic, electrolyte, acid - base, and volume disturbances generated by AKI and it can be used as a renal replacement therapy modality to treat AKI, both in and out of the intensive care unit setting.

Influence of different dialysis modalities in the measurement of resting energy expenditure in patients with acute kidney injury in ICU.

BACKGROUND: Currently, the execution of indirect calorimetry, which is considered the gold standard for measuring energy expenditure, is not indicate during dialysis, and it may interfere on nutritional therapy of these patients. This study aimed to evaluate the resting energy expenditure (REE) in patients with severe acute kidney injury treated by different modalities of dialysis and to identify whether dialysis influences on REE. METHODS: This was a prospective cohort study that evaluated patients admitted in intensive care units with diagnosis of acute kidney injury AKIN-3, mechanically ventilated, and submitted to conventional hemodialysis (CHD), extended hemodialysis (EHD) or high volume peritoneal dialysis (HVPD). Indirect calorimetry was performed at pre dialysis time and during the dialysis procedure. Parameters that could change REE were also evaluated. RESULTS: One-hundred patients undergoing 290 dialysis sessions were evaluated, with mean age 60.3 ± 17 years, 69% were male and 74% have died. There was no significant difference between REE of predialysis time and during dialysis time (2156 ± 659 kcal vs. 2100 ± 634 kcal, respectively, p = 0.15). No difference was observed in the REE before and during dialysis of different modalities. There were no differences between parameters pre and during dialysis of each modality. There was only a difference in norepinephrine dose, which was higher in pre dialysis time in HVPD and EHD modalities, compared with CHD modality. Moreover, during dialysis time, EHD modality had significantly higher VAD compared to other dialysis modalities. CONCLUSION: The three evaluated modalities did not change REE. Indirect calorimetry can be performed during dialysis procedures and there was no difference between ventilation parameters, sedatives use, body temperature and VAD in both moments.

Resting energy expenditure in critically ill patients: Evaluation methods and clinical applications.

Patients on intensive care present systemic, metabolic, and hormonal alterations that may adversely affect their nutritional condition and lead to fast and important depletion of lean mass and malnutrition. Several factors and medical conditions can influence the energy expenditure (EE) of critically ill patients, such as age, gender, surgery, serious infections, medications, ventilation modality, and organ dysfunction. Clinical conditions that can present with EE change include acute kidney injury, a complex disorder commonly seen in critically ill patients with manifestations that can range from minimum elevations in serum creatinine to renal failure requiring dialysis. The nutritional needs of this population are therefore complex, and determining the resting energy expenditure is essential to adjust the nutritional supply and to plan a proper diet, ensuring that energy requirements are met and avoiding complications associated with overfeeding and underfeeding. Several evaluation methods of EE in this population have been described, but all of them have limitations. Such methods include direct calorimetry, doubly labeled water, indirect calorimetry (IC), various predictive equations, and, more recently, the rule of thumb (kcal/kg of body weight). Currently, IC is considered the gold standard.

Resting energy expenditure in critically ill patients: Evaluation methods and clinical applications / Gasto energético de repouso em pacientes críticos: métodos de avaliação e aplicações clínicas

Summary Patients on intensive care present systemic, metabolic, and hormonal alterations that may adversely affect their nutritional condition and lead to fast and important depletion of lean mass and malnutrition. Several factors and medical conditions can influence the energy expenditure (EE) of critically ill patients, such as age, gender, surgery, serious infections, medications, ventilation modality, and organ dysfunction. Clinical conditions that can present with EE change include acute kidney injury, a complex disorder commonly seen in critically ill patients with manifestations that can range from minimum elevations in serum creatinine to renal failure requiring dialysis. The nutritional needs of this population are therefore complex, and determining the resting energy expenditure is essential to adjust the nutritional supply and to plan a proper diet, ensuring that energy requirements are met and avoiding complications associated with overfeeding and underfeeding. Several evaluation methods of EE in this population have been described, but all of them have limitations. Such methods include direct calorimetry, doubly labeled water, indirect calorimetry (IC), various predictive equations, and, more recently, the rule of thumb (kcal/kg of body weight). Currently, IC is considered the gold standard.

Resumo Os pacientes em cuidados intensivos apresentam alterações sistêmicas, metabólicas e hormonais, que podem afetar adversamente a condição nutricional e levar à rápida e importante depleção da massa magra e desnutrição. Vários fatores e situações clínicas podem exercer influência sobre o gasto energético (GE) de pacientes críticos, como idade, sexo, cirurgias, infecções graves, medicamentos, modalidade ventilatória e disfunção de órgãos. Dentre as condições clínicas que podem cursar com alteração do GE, encontra-se a lesão renal aguda (LRA), distúrbio complexo comumente observado em pacientes críticos, com manifestações que podem variar de mínimas elevações na creatinina sérica até insuficiência renal com necessidade dialítica. Dessa forma, essa população crítica apresenta necessidades nutricionais complexas e a determinação do gasto energético de repouso (GER) torna-se essencial para o ajuste da oferta nutricional e para o planejamento de uma nutrição adequada, assegurando que as necessidades energéticas sejam atingidas e evitando as complicações associadas à hiper ou hipoalimentação. Diversos métodos de avaliação do GE nessa população foram descritos, mas todos apresentam limitações. Dentre eles, destacam-se a calorimetria direta, a água duplamente marcada, a calorimetria indireta (CI), diversas equações preditivas e, mais atualmente, a regra de bolso (kcal/kg de peso). Atualmente, a CI é eleita o método padrão-ouro.

Poor Agreement between Predictive Equations of Energy Expenditure and Measured Energy Expenditure in Critically Ill Acute Kidney Injury Patients.

BACKGROUND: There are multiple equations for predicting resting energy expenditure (REE), but how accurate they are in severe acute kidney injury (AKI) patients is not clear. Our aim was to determine if predictive equations for estimated REE accurately reflect the requirements of AKI patients. METHODS: We included in this prospective and observational study AKI patients AKIN-3 assessed by indirect calorimetry (IC). Bland-Altman, intraclass correlation coefficient and precision (percentagem of predicted values within 10% of measured values) were performed to compare REE by equations with REE measured by IC. RESULTS: IC was applied in 125 AKI patients. The mean age was 62.5 ± 16.6 and 65.6% were male. Mean REE measured was 2,029.11 ± 760.4 kcal/day. There were low precision, and poor agreement between measured and predicted REE by the Harris-Benedict (HB), Mifflin, Ireton-Jones, Penn state, American College of Chest Physicians, and Faisy equations. HB without using injury factor was the least precise (18% of precision). Modified Penn state equation had the best precision, although the precision rate was only 41%. For all equations, the limits of agreement range were large leading to the potential under or overfeeding of individual patients. CONCLUSION: None of these equations accurately estimated measured REE in severe AKI patients and most of them underestimated energy needs.

Advances in peritoneal dialysis in acute kidney injury.

Peritoneal dialysis (PD) is a simple, safe, cheap, and efficient renal replacement therapy method. It can correct metabolic disorders and fluid overload in acute kidney injury (AKI) patients both in and out of the intensive care unit. Use of PD in AKI is enhanced by placement of a Tenckhoff catheter, which can be safely accomplished at the bedside. Some PD modalities, such as high-volume PD and continuous-flow PD, can provide dialysis doses and efficiency comparable to extracorporeal blood purification methods. PD is particularly suitable for neonates, children, and patients with refractory heart failure or who are otherwise hemodynamically unstable. PD should be considered in situations where systemic anticoagulation and/or vascular access are problematic. PD is limited by a lower efficiency that may produce inadequate renal replacement in larger and/or severely hypercatabolic patients. Fluid removal can be unpredictable, there is a risk of infection, and possible issues with mechanical ventilation. In this article, we discuss the use of PD in AKI, with emphasis on recent advances.

Mortalidade e prognóstico específico em pacientes com insuficiência renal aguda / Assessment of mortality and specific index in acute renal failure

Vários sistemas de estratificação de risco têm sido estudados com o objetivo de predizer a evolução de pacientes graves com insuficiência renal aguda (IRA). OBJETIVOS: Avaliar e comparar as taxas de mortalidade e o escore de severidade individual de necrose tubular aguda (ATN-ISS) em pacientes que desenvolveram IRA tratados em hospital universitário de atendimento predominantemente terciário. MÉTODOS: Foram estudados prospectivamente 103 pacientes com IRA por necrose tubular aguda (NTA), atendidos no Hospital das Clínicas da Faculdade de Medicina de Botucatu - UNESP, acompanhados até recuperação do quadro renal ou óbito. No momento da primeira avaliação do nefrologista foi aplicado o escore ATN-ISS. Os resultados foram apresentados em média ± desvio padrão ou mediana, com nível de significância de 5 por cento. RESULTADOS: Verificamos que 51,4 por cento eram do sexo masculino, com média de idade de 58 ± 36 anos. A mortalidade geral foi de 44,3 por cento, sendo estatisticamente maior nos pacientes provenientes de enfermarias cirúrgicas (52,7 por cento) quando comparados àqueles de enfermarias clínicas (35,3 por cento), e naqueles que realizaram diálise (63,8 por cento) quando comparados aos de tratamento conservador (23,5 por cento). O escore ATN-ISS apresentou boa confiabilidade, com elevado poder discriminatório (área sob a curva de 0,95) e boa calibração, principalmente a partir do quintil 3. CONCLUSÃO: Na população estudada, as taxas de mortalidade foram semelhantes àquelas encontradas na literatura. O escore ATN-ISS mostrou ser um índice prognóstico com grande confiabilidade, podendo ser aplicado na prática diária do nefrologista.

[Assessment of mortality and specific index in acute renal failure]. / Mortalidade e prognóstico específico em pacientes com insuficiência renal aguda.

UNLABELLED: A variety of systems of risk factor stratification have been studied to predict the outcome in acute renal failure (ARF). OBJECTIVES: Assess and compare mortality and the Acute Tubular Necrosis Individual Severity Score (ATN-ISS) in patients with AFR treated in a university hospital. METHODS: A prospective analysis was made of 103 patients with a diagnosis of intrinsic ARF admitted to the Hospital das Clinicas da Faculdade de Medicina de Botucatu, UNESP. Patients were followed up until recovery of renal function or death. The Score ATN-ISS was recorded during the first hours of the assessment by a nephrologist. Results were reported as median or mean +/- SD, with statistical significance of p < 0.05. RESULTS: Fifty-one percent of patients were male with a mean age of 58 +/- 36 years. Forty-four percent died in the hospital. Mortality was higher in patients from the surgical wards (52.7%) and in patients who were treated with dialysis (63.8%). The score ATN-ISS showed a good confidence level, with high discriminatory power (area under the curve of 0.95) and good accuracy. CONCLUSIONS: Mortality in this study was comparable to that found in literature. The ATN-ISS was shown to be a prognostic index with a high confidence level that could be routinely applied by nephrologists to patients with AFR.