Efficacy of 3% Saline vs. Conivaptan in Achieving Hyponatremia Treatment Goals

Hyponatremia is the most common electrolyte abnormality encountered in clinical practice, but its optimal management is still evolving. While guidelines for infusion rates of hypertonic saline (HS) have been introduced, there is a risk of underestimating the response in serum sodium concentration after therapy. Guidelines also have evaluated the use of vasopressin receptor antagonists as alternatives or supplements to standard therapies. This single-center retrospective study from The Methodist Hospital (TMH) compared the effect of HS and conivaptan intervention in the management of 49 patients with hyponatremia from January 2009 through November 2010. Demographics, volume status, medical history, medication data, and serum sodium concentration correction over 48 hours were analyzed. No significant difference was noted with regard to age, ethnicity, gender, volume status, use of medications known to cause hyponatremia, or comorbidities. Baseline serum sodium concentration was not significantly different between HS (120.5 ± 3.8 mEq/L) and conivaptan (118.3 ± 6.7 mEq/L) groups. Regardless of whether the patient was euvolemic or hypervolemic, no significant difference was noted in serum sodium concentration at 4, 12, 24, or 48 hours after initiation of treatment or in frequency of over-correction between groups. This study compares the effect of HS to conivaptan intervention in the management of hyponatremia. No significant differences were identified in adherence to treatment guidelines. Further, based on this small retrospective study, neither agent poses a significant risk of over-correction at 4, 24, or 48 hours of therapy.