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.

Clinical and nutritional factors associated with dialysis initiation and mortality in chronic kidney disease

BACKGROUND: Chronic kidney disease is worldwide recognized as a public health problem due to high rates of morbidity and mortality. At the end stage of the disease, which the glomerular filtration rate is equal or less than15 ml/min/1.73 m2, dialysis initiation is usually indicated. In the absence of a consensus on the best time of beginning, the aim of this study was to identify clinical and nutritional factors associated with clinical outcomes with the start of dialysis and death. METHODS: In a prospective cohort of 82 patients, clinical (underlying renal disease, renal survival time, systolic and diastolic blood pressure, estimated glomerular filtration rate) and nutritional data (protein intake, anthropometry, bioelectrical impedance test, and strength handgrip) were collected. We used mean and standard deviation ormedian and association of the variables with the outcome entry into dialysis or death, and a Cox regression model was applied. Statistical significance wasp< 0.05.RESULTS: Fifty-eight patients were included in group 1­G1 (without dialysis)­and 24 patients in group 2­G2(dialysis). The groups were different in blood urea nitrogen (p= <0.001), serum creatinine (p= 0.003), estimated glomerular filtration rate (p= 0.002), and serum phosphorus (p= 0.002). After multivariate analysis, only serumalbumin (HR 0.342,p= 0.004) and glomerular filtration rate (HR 0.001,p= 0.001) were associated with entry into dialysis and death. CONCLUSIONS: We concluded that lower levels of serum albumin and glomerular filtration rate values are associated with entry into dialysis or death.

Evaluation of energy metabolism in septic patients with and without AKI

BACKGROUND: The determination of resting energy expenditure (REE) in critically ill patients could prevent complications such as hypo- and hyper alimentation. This study aims to describe the REE in septic patients with and without acute kidney injury (AKI) and compare the REE estimated by the Harris-Benedict equation (HB) with the REE measured by indirect calorimetry (IC). METHODS: Prospective and observational study was performed. Septic patients older than 18 years, undergoing mechanical ventilation, with or without AKI defined by KDIGO criteria, and admitted to the Intensive Care Unit of University Hospital from Brazil were included. The REE was estimated by HB equation and measured by the IC within72 h after the diagnosis of sepsis and 7 days after the initial measure. RESULTS:Sixty-eight patients were evaluated, age was 62.5 ± 16.6 years, 64.7% were male, 63.2% had AKI, and SOFA was9.8 ± 2.35. The measured REE was 1857.5 ± 685.32 kcal, while the estimated REE was 1514.8 ± 356.72 kcal, with adequacy of 123.5 ± 43%. Septic patients without AKI (n= 25) and with AKI (n= 43) had measured REE statistically higher than the estimated one (1855.0 (1631.75­2052.75) vs. 1551.0 kcal (1349.0­1719.25),p= 0.007 and 1868.0(1219.5­2364.75) vs. 1388.0 kcal (1254.0­1665.5),p= 0.026, respectively). There was no significant difference between the two groups (with and without AKI) in measured and estimated REE (p= 0.63 and 0.64, respectively). There was no significant difference in evolutional REE (1845.95 ± 658.27 kcal vs. 1809.54 ± 755.08 kcal, p=0.86).CONCLUSIONS: The REE measured by IC was significantly higher than that estimated by HB equation in both septic with and without AKI. There was no significant difference in REE between the septic patients with and without AKI, suggesting that AKI does not influence the energy metabolism of septic patients.

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.