De novo Hyponatremia in Patients Undergoing Peritoneal Dialysis: A 12-month Observational Study / 대한신장학회지

ABSTRACT

PURPOSE: Hyponatremia occurs infrequently in patients undergoing peritoneal dialysis (PD). Nevertheless, one must understand its pathophysiology, since the therapeutic strategy differs from that of non- PD-related hyponatremia. This study examined the clinical features of hyponatremia in PD and evaluated the factors that may contribute to its development. METHODS: We retrospectively enrolled 51 normonatremic PD patients at Gachon University Gil Hospital, South Korea. Using the plasma sodium levels at month 13, the patients were divided into hyponatremia (Na+ or = 135 mEq/L) groups. Then, the clinical variables of these patients were examined, including peritoneal function and adequacy tests, and biochemical parameters. RESULTS: The de novo hyponatremia (n=8) and normonatremia (n=43) groups had no significant differences in baseline characteristics. At month 1, the serum albumin was lower in the hyponatremia group (p=0.022). In the peritoneal equilibration test analysis, the dialysate-to-plasma ratio for creatinine (D/ P(Cr)) measured after 13 months differed significantly between the two groups (p=0.007), while the maximum dip in sodium did not differ. No significant differences were observed in the normalized protein equivalent of nitrogen appearance, Kt/V, or residual renal function. CONCLUSION: Our data suggest that the development of hyponatremia is associated with a lower initial serum albumin level and increased D/P(Cr) in patients undergoing PD. Therefore, the serum sodium levels should be monitored more carefully in these patients.