(1322) Frequency and Risk Factors for Overcorrection of Serum Sodium in Severe Hyponatremia

Introduction: The primary objective was to identify the rate of sodium overcorrection. Secondary objectives were to determine the frequency of osmotic demyelination syndrome (ODS), describe treatment strategies utilized, and assess risk factors for overcorrection.

Methods: This study was a retrospective chart review of hyponatremic patients admitted to Temple University Hospital from August 2016 to December 2021. Patients were identified by serum sodium levels of < 120 mEq/L based on electronic medical record data query. Patients were included if they were ≥18 years of age and had a serum osmolality < 270 mOsm/kg. Exclusion criteria included missing follow up laboratory values, death within 48 hours, treatment for hyponatremia prior to admission, or considered a vulnerable patient population. Data collected included baseline characteristics, serum and urine chemistries, chronic medication use, and initial management of hyponatremia and/or overcorrection. Data was collected and stored in RedCap™. Statistical analysis was completed utilizing SPSS® and included univariate analysis and multivariate backwards stepwise logistic regression.

Results: A total of 171 patients met inclusion criteria. The median initial serum sodium was 115 mEq/L. Overcorrection (sodium change of > 8 mEq/L within 24 hours and/or use of desmopressin to re-lower serum sodium) occurred in 60.2% of patients. There were no documented cases of osmotic demyelination syndrome (ODS). Treatments included isotonic fluids (93.6%), loop diuretics (24.6%), and hypertonic saline (17.0%). On multivariate logistic regression, risk factors identified for overcorrection included treatment with isotonic saline therapy (OR 3.81; 95% CI, 1.27-11.46; P=0.017), alcohol abuse (OR 2.92; 95% CI, 1.28-6.66; P=0.011), ICU admission (OR 2.40; 95% CI, 0.90-6.38; P=0.079), initial sodium < 120 mEq/L (OR 0.83; 95% CI, 0.74-0.93; P=0.001), and treatment with loop diuretics (OR 0.34; 95% CI, 0.10-1.19; P=0.091).

Conclusions: The rate of overcorrection of severe hyponatremia was 60.2% with no cases of ODS. Treatment strategies were highly variable. Risk factors associated with overcorrection included lower initial serum sodium levels, ICU length of stay, alcohol abuse, and treatment with isotonic saline, while loop diuretics were found to be protective.