Relação entre função renal residual, ingestão e excreção de potássio em pacientes em diálise peritoneal
Data
2021-12
Tipo
Dissertação de mestrado
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Objetivo: Investigar as relações entre, excreção e ingestão de potássio comparando pacientes anúricos e não anúricos com doença renal crônica em diálise peritoneal. Métodos: Trata-se de um estudo de corte transversal que utilizou dados da linha de base de um ensaio clínico. Dados demográficos e clínicos foram coletados do prontuário e por meio de entrevista. O estado nutricional foi avaliado pelo índice de massa corporal, força de preensão manual e avaliação global subjetiva. A ingestão de potássio total e por grupo alimentar foi estimada pelo registro alimentar de três dias. As concentrações de potássio foram determinadas pelo método íon seletivo no soro (jejum de 12 horas), no dialisato de 24h e na urina de 24h dos pacientes com diurese superior a 200 mL/dia, os quais foram considerados não anúricos. Uma amostra de fezes foi coletada e a concentração de potássio foi determinada pelo método de espectrometria de absorção atômica e de emissão atômica. Resultados: Dos 52 pacientes estudados, 50% eram homens, a idade média 52,6±14,0 anos; 28,8% com diabetes mellitus; índice de massa corporal de 25,7±4,0 kg/m² e tempo em diálise peritoneal 19,5 [7,0-44,2] meses. A maioria dos pacientes era bem nutrido de acordo com a avaliação global subjetiva (n=49; 94,2%). Os pacientes foram divididos em anúricos (n=17, 33%) e não anúricos (n=35, 67%). Os não anúricos apresentaram volume urinário de 1223,7±542,8 mL/24h, função renal residual 5,30±2,86mL/min/1,73m² e potássio urinário 22,2±11,1 mEq/24h. Esse grupo de pacientes apresentava maior índice de massa corporal e força de preensão manual; maior concentração sérica de albumina; níveis mais baixos proteína C-reativa, configurando, melhor condição clínica e nutricional. Comparados aos anúricos o grupo não anúrico apresentou respectivamente menor concentração de potássio no dialisato (24,8±5,3vs 30,9±5,9 mEq/dia; p=0,001) maior ingestão total de potássio (44,5±16,7 vs 35,1±8,1 mEq/dia; p=0,009), e de potássio proveniente de frutas (6,2 [2,4-14,7] vs 2,9 [0,0-6,0] mEq/dia; p=0,018), e não diferiu quanto a concentração de potássio sérico (4,8±0,6 vs 4,8±0,9 mEq/L; p=0,799) e quanto a concentração de potássio nas fezes (2,2±0,5 vs 2,1±0,7mEq/L; p=0,712 ). Nos pacientes não anúricos, a ingestão de potássio se correlacionou diretamente com o potássio da urina (r=0,40; p=0,017), mas não com o potássio sérico, potássio do dialisato ou com potássio das fezes. Nos anúricos a ingestão de potássio tendeu a se correlacionar positivamente com o potássio sérico (r=0,48; p=0,051) e não houve correlação com o potássio do dialisato ou com potássio nas fezes. Conclusão: A presença de função renal residual foi um fator importante na excreção de potássio, contribuindo para manutenção da potassemia, mesmo com ingestão maior desse nutriente quando comparada com a dos pacientes anúricos. Esses resultados sugerem a possibilidade de maior flexibilidade na ingestão de potássio, possibilitando adoção de uma dieta de melhor qualidade com maior consumo de frutas e hortaliças em pacientes que mantém a função renal residual.
Objective: To investigate the relationship between, potassium intake and excretion comparing anuric and non-anuric patients with chronic kidney disease on peritoneal dialysis. Methods: This is a cross-sectional study using baseline data from a clinical trial. Clinical and demographic data were collected from the medical record and by interview. Nutritional status was evaluated by body mass index, handgrip strength and subjective global assessment. Total potassium intake and potassium intake from food groups were estimated by the three-day food record. Potassium concentration was determined by the ion-selective method in serum (12-hour fasting), 24-hour dialysate, and 24-hour urine of patients with diuresis higher than 200 mL/day, who were considered non-anuric. A stool sample was collected and the potassium concentration was determined by the atomic absorption and emission spectrometry methods. Results: Of the 52 patients studied, 50% were men, with a mean age of 52.6±14.0 years; 28,8% had diabetes mellitus; body mass index 25.7±4.0 kg/m² and length on peritoneal dialysis 19.5 [7.0-44.2] months. The majority of the patients were well nourished according to subjective global assessment (n=49; 94.2%). The patients were divided into anuric group (n=17, 33%) and non-anuric group (n=35, 67%). The non-anuric patients had urinary volume of 1223.7±542.8 mL/24h, residual renal function of 5.30±2.86 mL/min/1.73m² and urinary potassium of 22.2±11.1 mEq/24h. This group of patients had higher body mass index and handgrip strength; higher serum albumin concentration; lower levels of C-reactive protein, configuring a better clinical and nutritional status. Compared to anuric patients, the non-anuric group presented respectively lower dialysate potassium concentration (24.8±5.3 vs 30.9±5.9 mEq/day; p=0.001) higher total potassium intake (44.5±16.7 vs 35.1±8.1 mEq/day; p=0.009), and of potassium from fruits (6.2 [2.4-14.7] vs 2.9 [0.0-6.0] mEq/day; p=0.018), and did not differ regarding serum potassium concentration (4.8±0.6 vs 4.8±0.9 mEq/L; p=0.799) and fecal potassium concentration (2.2±0.5 vs 2.1±0.7mEq/L; p=0.712 ). In non-anuric patients, potassium intake correlated directly with urine potassium (r=0.40; p=0.017), but not with serum potassium, dialysate potassium or fecal potassium. In the anuric group, potassium intake tended to correlate positively with serum potassium (r=0.48; p=0.051) and there was no correlation with dialysate potassium or fecal potassium. Conclusion: The presence of residual renal function was an important factor in potassium excretion, contributing to maintenance of serum potassium, even with higher intake of this nutrient when compared to anuric patients. These results suggest the possibility of greater flexibility in potassium intake, allowing the adoption of a better quality diet with higher intake of fruits and vegetables in patients who maintain residual renal function on peritoneal dialysis.
Objective: To investigate the relationship between, potassium intake and excretion comparing anuric and non-anuric patients with chronic kidney disease on peritoneal dialysis. Methods: This is a cross-sectional study using baseline data from a clinical trial. Clinical and demographic data were collected from the medical record and by interview. Nutritional status was evaluated by body mass index, handgrip strength and subjective global assessment. Total potassium intake and potassium intake from food groups were estimated by the three-day food record. Potassium concentration was determined by the ion-selective method in serum (12-hour fasting), 24-hour dialysate, and 24-hour urine of patients with diuresis higher than 200 mL/day, who were considered non-anuric. A stool sample was collected and the potassium concentration was determined by the atomic absorption and emission spectrometry methods. Results: Of the 52 patients studied, 50% were men, with a mean age of 52.6±14.0 years; 28,8% had diabetes mellitus; body mass index 25.7±4.0 kg/m² and length on peritoneal dialysis 19.5 [7.0-44.2] months. The majority of the patients were well nourished according to subjective global assessment (n=49; 94.2%). The patients were divided into anuric group (n=17, 33%) and non-anuric group (n=35, 67%). The non-anuric patients had urinary volume of 1223.7±542.8 mL/24h, residual renal function of 5.30±2.86 mL/min/1.73m² and urinary potassium of 22.2±11.1 mEq/24h. This group of patients had higher body mass index and handgrip strength; higher serum albumin concentration; lower levels of C-reactive protein, configuring a better clinical and nutritional status. Compared to anuric patients, the non-anuric group presented respectively lower dialysate potassium concentration (24.8±5.3 vs 30.9±5.9 mEq/day; p=0.001) higher total potassium intake (44.5±16.7 vs 35.1±8.1 mEq/day; p=0.009), and of potassium from fruits (6.2 [2.4-14.7] vs 2.9 [0.0-6.0] mEq/day; p=0.018), and did not differ regarding serum potassium concentration (4.8±0.6 vs 4.8±0.9 mEq/L; p=0.799) and fecal potassium concentration (2.2±0.5 vs 2.1±0.7mEq/L; p=0.712 ). In non-anuric patients, potassium intake correlated directly with urine potassium (r=0.40; p=0.017), but not with serum potassium, dialysate potassium or fecal potassium. In the anuric group, potassium intake tended to correlate positively with serum potassium (r=0.48; p=0.051) and there was no correlation with dialysate potassium or fecal potassium. Conclusion: The presence of residual renal function was an important factor in potassium excretion, contributing to maintenance of serum potassium, even with higher intake of this nutrient when compared to anuric patients. These results suggest the possibility of greater flexibility in potassium intake, allowing the adoption of a better quality diet with higher intake of fruits and vegetables in patients who maintain residual renal function on peritoneal dialysis.