(1634) Hyponatremia Associated With Intravenous Vasopressin in the Treatment of Septic Shock

Introduction: Intravenous vasopressin may cause hyponatremia by stimulation of renal V2 receptors. However, the clinical significance of vasopressin-induced hyponatremia in patients with septic shock has not been well described. The purpose of this study was to assess hyponatremia in patients with septic shock who received intravenous vasopressin in addition to norepinephrine compared to those who received norepinephrine alone.

Methods: This was a single-center, retrospective cohort study of patients admitted to the ICU from January 1, 2023, through December 31, 2023. This study compared a group of patients with septic shock who received treatment with vasopressin plus norepinephrine to those who received norepinephrine alone. Outcomes included: lowest serum sodium during treatment, proportion of patients developing mild (serum sodium 130-134 mmol/L), moderate (125-129 mmol/L), or profound ( < 125 mmol/L) hyponatremia, proportion with moderate (nausea without vomiting, confusion, headache) or severe (vomiting, cardiorespiratory distress, abnormal and deep somnolence, seizures, coma) symptoms of hyponatremia, and receipt of treatment for hyponatremia.

Results: A total of 57 patients were included in this study, with 30 patients in the norepinephrine alone group and 27 patients in the vasopressin plus norepinephrine group. In the norepinephrine alone group, 12 patients (40.0%) experienced mild hyponatremia compared with 19 patients (70.4%) in the vasopressin plus norepinephrine group (p=.02). The median lowest serum sodium was 135 mmol/L (132-137 mmol/L) in the norepinephrine alone group compared with 133 mmol/L (IQR, 130-135 mmol/L) in the vasopressin plus norepinephrine group (p=.02). There were numerically higher, but not statistically significant, proportions of patients in the vasopressin plus norepinephrine group who experienced moderate or profound hyponatremia, symptoms of hyponatremia, and receipt of treatment for hyponatremia.

Conclusions: Hyponatremia was more common in patients who received vasopressin, but most cases were mild and had an unclear clinical significance. Clinicians should be aware of the potential for hyponatremia in those receiving vasopressin. This study may help generate hypotheses for further research on vasopressin-induced hyponatremia.