Serum Sodium Concentration During Arginine Vasopressin Infusion in Critically Ill Children.

Background: Intravenous arginine vasopressin is increasingly used for the treatment of critically ill children. It bears the risk of hyponatraemia with potential severe long-term sequelae, but data on hyponatraemia as a side effect of continuous vasopressin infusion for paediatric intensive care patients is scarce.

Methods: In this retrospective analysis performed at a tertiary care paediatric intensive care unit with 2000 annual admissions, patients were included if they were treated with intravenous vasopressin between 2016 and 2022. Baseline sodium concentrations, lowest sodium concentrations during arginine vasopressin treatment, and time to lowest sodium concentration (nadir) were derived.

Results: In total, 170 patients with a median age of 4 months [interquartile range, IQR, 0-33] were included, 92.4% underwent surgery, and 28.8% died. Median arginine vasopressin dose rate was 0.027 IU/kg/h [0.019-0.036] and arginine vasopressin was started 3.2 [0-26] h after intensive care admission. Median arginine vasopressin application duration was 13.6 h [6.2-32.6]. Baseline sodium was 141 mmol/L [138-145], and lowest median sodium during arginine vasopressin infusion was 137 mmol/L [132-141] (nadir at 8.4 h [1.0-28.1] after arginine vasopressin start). Hyponatraemia (<135 mmol/L) occurred in 38.2% of patients during AVP treatment, and physicians administered a median of 10.2 mmol/kg/d [6.2-16.4] sodium during arginine vasopressin therapy.

Conclusions: Under arginine vasopressin infusion, hyponatraemia was common, although high daily doses of sodium were administered to keep the serum values in physiologic ranges. This emphasises the need for close electrolyte monitoring and sodium substitution in children and adolescents under arginine vasopressin treatment to avoid hyponatraemia and related sequelae.