Acute Effects of Vasopressin Arginine Infusion in Children with Congenital Heart Disease

Background: The use of vasopressin has been increased in recent years in children after congenital heart surgery. However, there is limited information regarding its effects on cardiac output, systemic oxygen delivery, and myocardial energetics. The purpose of this study is to characterize the effects of vasopressin infusions on hemodynamics and systemic oxygen delivery in children with congenital heart disease

Methods: A retrospective, single-center study of patients with congenital heart disease who received vasopressin infusions in a pediatric cardiac intensive care unit between January 2019 and May 2020. The measured values collected for study were systolic and diastolic blood pressure, heart rate, arterial oxygen saturation as determined by pulse oximetry, arterial pH, arterial partial pressure of oxygen, arterial partial pressure of carbon dioxide, serum lactate, serum sodium, and renal and cerebral oximetry based on near-infrared spectroscopy. The calculated values for this study were the difference between arterial and NIRS oximetry, the reno-cerebral near-infrared spectroscopy gradient and the vasoinotrope score. A Wilcoxon signed-rank test was utilized to compare values of paired continuous variables before and after initiation of the vasopressin infusion. Correlations were assessed using Spearman correlation analyses and stepwise regressions were completed.

Results: A total of 26 vasopressin infusions among 20 unique patients were included in the final analyses. Of these 26 vasopressin infusions, 18 were in patients with biventricular circulation and 8 were in patients with functionally univentricular circulation. The median vasopressin infusion dose at initiation was 0.4 (0.1-1) milliunits/kg/min. For the entire cohort 2 h after the initiation of vasopressin, systolic blood pressure increased to 8.4 mmHg, p < 0.01, but no significant correlation was found to markers of systemic oxygen delivery. Similar results were obtained when only those with biventricular circulation were considered. Those with functionally univentricular circulation were not found to have any statistically significant rise in blood pressure.

Conclusion: Vasopressin infusions appear to statistically significantly increase systolic blood pressure in children with congenital heart disease who have a biventricular but not functionally univentricular circulation. Even when an increase in systolic blood pressure is present, systemic oxygen delivery did not improve.