Timing and response to vasopressin in children in a paediatric intensive care unit

To describe the patterns of vasopressin use and the effect of timing in critically ill children. Retrospective study between 2017 - 2023 in children less than 18 years old in a tertiary paediatric intensive care unit (PICU). Vasopressin was administered in 453/10,750 (4%) of admissions and of these 453, 43% had congenital heart disease and 21% had sepsis. The median starting dose was 0.02 Units/kg/hr [IQR;0.02–0.04] and vasopressin was commenced 13.9 h [IQR;2.5–67.7] after admission. Vasopressin was commenced within 24 h of noradrenaline initiation in 406 admissions. The median time from noradrenaline to vasopressin initiation was 4 h [IQR 16.3–0.5] and the median noradrenaline dose at vasopressin initiation was 0.15 µg/k/min [IQR 0.1–0.25]. Noradrenaline was able to be reduced following initiation of vasopressin, irrespective of timing between the two drugs. In an exploratory, multivariable logistic regression analysis, shorter time between noradrenaline and vasopressin initiation, measured continuously, was associated with reduced mortality (adjusted OR 0.94 [95%CI 0.91–0.98]). Arrhythmias, gastrointestinal and limb ischaemia during admission were higher in children who received vasopressin. Vasopressin is administered to 4% of admissions to a large tertiary PICU; commonly in sepsis and congenital heart disease. After vasopressin initiation, noradrenaline dose decreased irrespective of timing after noradrenaline, however, earlier timing may be associated with reduced mortality.