Evaluating Hyponatremia in Non-Diabetic Uremic Patients on Peritoneal Dialysis

Abstract

♦ Background: An approach to hyponatremia in uremic patients on peritoneal dialysis (PD) necessitates the assessment of intracellular fluid volume (ICV) and extracellular volume (ECV). The aim of the study was to evaluate the association of plasma sodium (Na + ) concentration and body fluid composition and identify the causes of hyponatremia in non-diabetic PD patients. ♦ Methods: Sixty non-diabetic uremic patients on PD were enrolled. Baseline body fluid composition, biochemistry, hand-grip test, peritoneal membrane characteristics, dialysis adequacy, Na + and water balance, and residual renal function (RRF) were measured. These parameters were reevaluated for those who developed hyponatremia, defined as serum Na + concentration < 132 mmol/L and a decline in serum Na + > 7 mmol/L, during monthly visits for 1 year. Body fluid composition was determined by multi-frequency bioelectrical impedance (BIA). ♦ Results: There was no significant correlation between serum Na + concentrations and any other parameters except a negative correction with overnight ultrafiltration (UF) amount (p = 0.02). The ICV/ECV ratio was positively correlated with serum albumin (p < 0.005) and hand grip strength (p < 0.05). Over 1 year, 9 patients (M:F = 3:6, aged 35 -77) with 4 different etiologies of hyponatremia were identified. Hyponatremic patients with a body weight (BW) loss had either an increased ICV/ECV ratio associated with primarily a negative Na + balance (n = 2) or a reduced ratio of ICV/ECV associated with malnutrition (n = 2). In contrast, hyponatremic patients with a BW gain had either a reduced ICV/ECV ratio associated with a rapid loss of RRF and a higher peritoneal permeability (n = 2) or a normal to increased ICV/ECV ratio associated with high water intake (n = 3). ♦ Conclusion: Besides BW change and ultrafiltration rate, the assessment of ICV/ECV ratio is valuable in identifying the etiologies of hyponatremia in PD and provides a guide for optimal therapy.

A case report of a man on peritoneal dialysis having intractable hyponatremia

“…This may be characterized by BW loss and increased ICV/ECV ratio. [ 3 , 4 ] However, in malnourished patients with low protein intake, intracellular K + and phosphate will be lost concomitantly to be electroneutral, producing a primary deficit of K + and phosphate. [ 4 ] Reduced intracellular tonicity will cause intracellular water shifting to extracellular components, subsequently diluting extracellular osmoles (mainly Na + ).…”

“…These include water intake in excess of sodium and/or low water excretion (insufficient ultrafiltration); deficiency in extracellular fluid sodium (low sodium diet) and/or excess sodium loss (excessive ultrafiltration); phosphate/potassium deficit leading to water redistribution; free water excess due to an inadequate vasopressin suppression secondary to drugs (opioids, psychotropic medications), endocrinopathies (hypothyroidism, hypoaldosteronism), and other diseases (neurologic, pulmonary, or paraneoplastic ones); and change in the set point for serum sodium tonicity. [ 3 , 4 ] Despite these, the diagnosis and management of hyponatremia often remain problematic. Here, we report a male case with hyponatremia on PD patients likely due to malnutrition, highlighting the significant diagnostic and therapeutic challenges.…”

mPGES-1-Derived PGE2 Contributes to Indoxyl Sulfate-Induced Mesangial Cell Proliferation

“…RKF is particularly important for maintaining a better status of health even in the patients with dialysis therapy [28-30]. RKF not only benefits the urinary excretion of salt and water, but also helps to remove the large molecular uremic toxins which can’t be effectively cleared by dialysis [2, 4, 5].…”

Dysnatremias in Chronic Kidney Disease: Pathophysiology, Manifestations, and Treatment

“…Table 1 shows the incidence and prevalence of hyponatremia in the studies of the general population, CKD not on dialysis, hemodialysis, and peritoneal dialysis ( 10 , 27 – 54 ). Table 2 shows the incidence and prevalence of hypernatremia in the same population segments ( 10 , 28 – 30 , 32 – 36 , 38 – 40 , 47 , 53 – 55 ). The values for prevalence and incidence related to dysnatremias vary widely in each of the four categories of patients in Tables 1 , 2 and overlap substantially among the four patient categories.…”

“…For these reasons, the incidence and prevalence of dysnatremias should be calculated separately in diabetic and non-diabetic CKD populations. Only one small study calculated the prevalence of hyponatremia in non-diabetic peritoneal dialysis patients ( 53 ). This study, which assessed changes in TBW and extracellular volume by repeated bioimpedance measurements, identified factors associated with the development of hyponatremia during peritoneal dialysis.…”