(1439) Hypernatremia in Children Following Discontinuation of Vasopressin Used for Hemodynamic Support

Introduction: Transient diabetes insipidus with hypernatremia has been reported after stopping vasopressin infusion in adults but is less frequently documented in children. This retrospective cohort study aims to examine the incidence and clinical characteristics associated with hypernatremia following the discontinuation of vasopressin in children and neonates.

Methods: After IRB approval, we analyzed data from neonates and children (≤18 years) who received vasopressin for hemodynamic support between 2013 and 2023. Patients who received vasopressin for non-hemodynamic reasons were excluded. Hypernatremia was defined as maximum Na values >149 mmol/L. Chi-square and Mann-Whitney U tests were used to compare two groups (post-vasopressin hypernatremia and non-hypernatremia).

Results: Of 660 children included, 75.5% were neonates and infants. Most were admitted to CICU, and 62.6% underwent cardiac surgical procedures. The median (IQR) dose and duration of vasopressin infusions were 1(0.6-2) mcg/kg/min and 39 (27-784) hours, respectively. Hypernatremia was present in 95 (14.4%) patients after stopping vasopressin and was more common with diagnoses of PPHN (25% vs 13%; p=0.007) and meconium aspiration syndrome (31% vs 13.6%; p=0.009) and less common with admission in CICU (11.5% vs 22%; p=0.001). Children in the hypernatremia group received diuretics (32.6% vs 22.5%; p=0.03) and 3% NaCl boluses (13.7% vs 4.8%; p=0.002) more often, and the fluid intake (147 vs 128 ml/kg/day; p< 0.001) and fluid balance (127 vs 82 ml/kg/day; p=0.027) were higher during vasopressin infusion. Polyuria (urine output >6 in neonates and >4 ml/kg/hr for older children) after stopping vasopressin infusion was present in 52.7% of each group. The median rise in Na (11 (6-19) vs 2 (0-6) mmol/L; p< 0.01) and BUN/creatinine ratio (19.1 (10-43.2) vs 13.9 (4.6-29.3); p=0.011) after stopping vasopressin were higher in the hypernatremic group. Duration and maximum dose of vasopressin infusion and mortality (16.8% vs 23.4%) were not significantly different between the groups.

Conclusions: Hypernatremia after stopping vasopressin is not uncommon and is seen most often in non-cardiac surgical patients who received higher amounts of fluid and sodium during vasopressin infusion. It is not related to vasopressin infusion dose or duration.