Effect of Change in Sodium after Slow Low-Efficiency Dialysis in Critically Ill Patients with Acute Kidney Injury

The effect of sodium (Na) correction by slow low-efficiency dialysis (SLED) in dysnatremic (135 mEq/L 145 mEq/L) critically ill patients is unclear.

Prospective observational study enrolled dysnatremic critically ill adult patients with acute kidney injury undergoing the first SLED as cases and normonatremic patients as controls. Baseline and SLED-related parameters and 30-day mortality were noted.

100 dysnatremic and 51 normonatremic patients were included, with a median age of 31 (25-52) years and median admission SOFA scores of 10 (9-12). Patients with dysnatremia at study inclusion had a mortality of 53%, with the highest mortality in severe hypernatremia (Na >160 mEq/L) (75%), followed by those with severe hyponatremia (Na <120 mEq/L) (68.6%). SLED-associated natremia change >10 mEq/L was significantly associated with mortality, in patients with mild dysnatremia and normonatremia (Na: 130-150) (p < 0.001), and not in those with moderate to severe dysnatremia (Na <130 and Na >150) (p = 0.72). Upon multivariate logistic regression analysis, a model with pre-SLED pH, dialyzate-pre-SLED Na difference, and duration of SLED significantly predicted SLED-associated natremia change (R2 0.18, p = 0.001).

SLED can be safely and effectively performed in critically ill adults with dysnatremia requiring renal replacement therapy with mortality comparable to normonatremic controls.