Kidney Week

Abstract: FR-OR49

One Size Does Not Fit All: Real World Data on the Safety of Bolus Hypertonic Saline for Symptomatic Hyponatremia

Session Information

• Fluid, Electrolyte, and Acid-Base Disorders Research
  November 04, 2022 | Location: W308, Orange County Convention Center‚ West Building
  Abstract Time: 05:42 PM - 05:51 PM

Category: Fluid‚ Electrolyte‚ and Acid-Base Disorders

• 1002 Fluid‚ Electrolyte‚ and Acid-Base Disorders: Clinical

Authors

• Pelouto, Anissa, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, Netherlands

Anissa Pelouto, MD, MSc

• Zandbergen, Adrienne Anne Marie, Department of Internal Medicine, Erasmus Medical Center, Rotterdam, Netherlands

Adrienne Anne Marie Zandbergen,

• Hoorn, Ewout J., Department of Internal Medicine, Erasmus Medical Center, Rotterdam, Netherlands

Ewout J. Hoorn,

Background

Symptomatic hyponatremia is a medical emergency that warrants prompt correction. The European and American guidelines recommend rapid bolus-wise infusion of hypertonic saline with fixed volumes of 150 and 100ml regardless of body weight. However, this approach may lead to overcorrection, which may be harmful in patients with “acute on chronic” or chronic hyponatremia with symptoms. Here, our aim was to assess the safety of the current “one size fits all” approach in clinical practice. We hypothesized that lower BMI results in more overcorrection.

Methods

We retrospectively assessed biochemical and clinical outcomes in patients treated with fixed bolus hypertonic saline (150 or 100ml) for hyponatremia at Erasmus Medical Center between July 2017 and July 2021. The cut-off for low BMI was 21 kg/m², based on the lowest quartile of the cohort. Primary outcome was overcorrection, defined as an increase in plasma sodium (pNa) >10 mmol/L/24 hours, >18 mmol/L/48 hours, or need for pNa relowering (use of hypotonic fluids and/or desmopressin). We performed multivariable logistic regression analyses to identify predictors for the primary outcome, adjusting for known risk factors including baseline pNa level, volume depletion and hypokalemia.

Results

A total of 183 patients were included for analysis (median age 63, IQR 55-7; 44% males, median baseline pNa 120 mmol/l, IQR 116-122). Overcorrection occurred in 20% of patients. The overcorrection rate was significantly higher in patients with low BMI compared to patients without low BMI (37% versus 14%, P<0.001). In addition, BMI was independently associated with overcorrection both when analyzed continuously (aOR 0.86, 95%CI 0.76-0.96) and when categorized as low BMI (aOR 4.24, 95%CI 1.67–10.80). Furthermore, we confirm that lower baseline pNa (aOR 0.87, 95%CI 0.80–0.94), volume depletion (aOR 5.81, 95%CI 2.11–16.00) and hypokalemia (aOR 5.62, 95%CI 1.89–16.91) are independent risk factors of overcorrection.

Conclusion

We show that the current “one size fits all’’ approach – bolus infusion of hypertonic saline with fixed volumes – exposes patients with low BMI to a significantly higher risk of overcorrection. Therefore, we recommend volume adjustments in patients with low BMI. Future prospective studies should test whether a weight-based approach is indeed safer.