Hypertonic saline for hyponatremia: risk of inadvertent overcorrection.
OBJECTIVE
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.


METHODS
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.
Mohmand
Hashim K
HK
Department of Medicine, University of Cincinnati Medical Center, Cincinnati, Ohio, USA. hashimkm@yahoo.com
Issa
Dany
D
Ahmad
Zubair
Z
Cappuccio
Joseph D
JD
Kouides
Ruth W
RW
Sterns
Richard H
RH
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000628:therapy*; D007177:Inappropriate ADH Syndrome / Q000097:blood / Q000150:complications; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012462:Saline Solution, Hypertonic / Q000008:administration & dosage* / Q000009:adverse effects; D012964:Sodium / Q000097:blood
D012462:Saline Solution, Hypertonic; D012964:Sodium