RESUMEN
BACKGROUND: Residual kidney function (RKF) conveys a survival benefit among dialysis patients, but the mechanism remains unclear. Improved volume control, clearance of protein-bound and middle molecules, reduced inflammation and preserved erythropoietin and vitamin D production are among the proposed mechanisms. Preservation of RKF requires techniques to measure it accurately to be able to uncover factors that accelerate its loss and interventions that preserve it and ultimately to individualize therapy. The average of renal creatinine and urea clearance provides a superior estimate of RKF in dialysis patients, when compared with daily urine volume. However, both involve the difficult task of obtaining an accurate 24-h urine sample. SUMMARY: In this article, we first review the definition and measurement of RKF, including newly proposed markers such as serum levels of beta2-microglobulin, cystatin C and beta-trace protein. We then discuss the predictors of RKF loss in new dialysis patients. We review several strategies to preserve RKF such as renin-angiotensin-aldosterone system blockade, incremental dialysis, use of biocompatible membranes and ultrapure dialysate in hemodialysis (HD) patients, and use of biocompatible solutions in peritoneal dialysis (PD) patients. Despite their generally adverse effects on renal function, aminoglycoside antibiotics have not been shown to have adverse effects on RKF in well-hydrated patients with end-stage renal disease (ESRD). Presently, the roles of better blood pressure control, diuretic usage, diet, and dialysis modality on RKF remain to be clearly established. Key Messages: RKF is an important and favorable prognostic indicator of reduced morbidity, mortality, and higher quality of life in both PD an HD patients. Further investigation is warranted to uncover factors that protect or impair RKF. This should lead to improved quality of life and prolonged lifespan in patients with ESRD and cost-reduction through patient centeredness, individualized therapy, and precision medicine approaches.
Asunto(s)
Fallo Renal Crónico/terapia , Pruebas de Función Renal , Riñón/fisiopatología , Diálisis Renal/métodos , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Soluciones para Diálisis , Tasa de Filtración Glomerular/fisiología , Humanos , Fallo Renal Crónico/diagnóstico , Fallo Renal Crónico/mortalidad , Fallo Renal Crónico/fisiopatología , Calidad de Vida , Diálisis Renal/instrumentación , Sistema Renina-Angiotensina/efectos de los fármacos , Sistema Renina-Angiotensina/fisiología , Resultado del TratamientoRESUMEN
BACKGROUND: To investigate the efficacy and safety of oral N-acetylcysteine (NAC) for preserving residual renal function in patients undergoing hemodialysis. METHODS: Randomized, multi-center, parallel-group, open-label clinical trial (Registration No. IRCT 2014071418482N1). 54 patients who have been undergoing hemodialysis for at least 3 months and had residual urine volume >100 ml/24 h were randomly allocated to NAC or no medication. Residual renal function evaluated by (1) estimated glomerular filtration rate (GFR), (2) 24 h urine volume, and (3) renal Kt/V. GFR and Kt/V was determined at baseline and after 3 months. 24 h urine volume was measured at baseline, after 1, 2, and 3 months. RESULTS: Intention-to-treat analysis was performed on 47 patients (NAC = 26, control = 21). GFR in patients receiving NAC improved, whereas in the control arm a decline of 1.0 ml/min/1.73 m2 was recorded (3.59 vs. 2.11 ml/min/1.73 m2, effect size = 17.0 %, p = 0.004). For 24 h urine volume, the between-group difference after 1 month was significant (669 vs. 533 ml/24 h, effect size = 15.4 %, p = 0.004). After 3 months, 24 h urine volume in the NAC arm was on average 137 ml higher than in the control group, and the difference reached near significance (673 vs. 536 ml/24 h, p = 0.072). In the follow-up visit, Kt/V was higher in the NAC arm but the difference did not reach statistical significance (0.81 vs. 0.54, p = 0.152). CONCLUSION: Three months treatment with NAC appears to be effective in preserving renal function in patients undergoing hemodialysis and the medication is generally well-tolerated.