Hypertonic saline for hyponatremia: risk of inadvertent overcorrection

Clin J Am Soc Nephrol. 2007 Nov;2(6):1110-7. doi: 10.2215/CJN.00910207. Epub 2007 Oct 3.


Background and objectives: Data regarding dosage-response relationships for using hypertonic saline in treatment of hyponatremia are extremely limited. Objectives of this study were to assess adherence to previously published guidelines (limiting correction to <12 mEq/L per d and <18 mEq/L per 48 h) in treating hyponatremia with hypertonic saline and to determine the predictive accuracy of the Adrogué-Madias formula.

Design, setting, participants & measurements: A retrospective review was conducted of all 62 adult, hyponatremic patients who were treated with hypertonic saline during 5 yr at a 528-bed, acute care, teaching hospital.

Results: Median infusion rate was 0.38 ml/kg per h, increasing serum sodium concentration by 0.47 +/- 0.05 mEq/L per h, 7.1 +/- 0.6 mEq/L per 24 h, and 11.3 +/- 0.7 mEq/L per 48 h. In 11.3% of cases, the increase was >12 mEq/L per 24 h and in 9.7% was >18 mEq/L per 48 h. No patient's rate was corrected by >25 mEq/L per 48 h. Among patients with serum sodium <120 mEq/L, the observed increase in sodium exceeded the rise predicted by the Adrogué-Madias formula in 74.2%; the average correction in overcorrectors was 2.4 times the predicted. Inadvertent overcorrection was due to documented water diuresis in 40% of cases.

Conclusions: The Adrogué-Madias formula underestimates increase in sodium concentration after hypertonic saline therapy. Unrecognized hypovolemia and other reversible causes of water retention pose a risk for inadvertent overcorrection. Hypertonic saline should be infused at rates lower than those predicted by formulas with close monitoring of serum sodium and urine output.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Female
  • Humans
  • Hyponatremia / therapy*
  • Inappropriate ADH Syndrome / blood
  • Inappropriate ADH Syndrome / complications
  • Male
  • Middle Aged
  • Retrospective Studies
  • Saline Solution, Hypertonic / administration & dosage*
  • Saline Solution, Hypertonic / adverse effects
  • Sodium / blood


  • Saline Solution, Hypertonic
  • Sodium