Vasopressin as adjunctive therapy in pulmonary hypertension associated with refractory systemic hypotension in term...

The use of vasopressin as an adjunctive therapy in pulmonary hypertension associated with refractory systemic hypotension has increased. The objective of our study is to describe its effects on term infants.

Retrospective observational study. Setting in a referral level IV neonatal intensive care unit from a middle-income region. The patients are term neonates admitted to our NICU who required vasopressin due to severe Pulmonary Hypertension and refractory hypotension during a 49-month period (December 2019 and December 2023).

We identified 68 term infants, all in mechanical ventilation, receiving inhaled nitric oxide (iNO), and a phased protocol management for hypotension. Vasopressin was a started at a mean of 2 days with a mean duration of 80 h. Regarding hemodynamic outcome: diastolic, systolic, and median systemic pressure significantly increased during the first 4 h of treatment, as well as arterial pH and urine output. Accordingly, lactate and Vasoactive Inotropic Score (VIS) score decreased after 4 and 8 h, respectively, after vasopressin was started. Regarding oxygenation markers: oxygen requirements and mean airway pressure decreased significantly (and therefore the oxygenation index decreased in concordance) after 4 h of vasopressin. Echocardiographic indices of pulmonary hypertension progressively improved after vasopressin infusion with a significant decrease of tricuspid ingurgitation velocities and the rate of right-to- left ductal shunt through the ductus arteriosus. In the same way, left and right ventricular output increased after the initiation of vasopressin.

This study showed that the use of vasopressin in neonates with persistent pulmonary hypertension was associated with a rapid and significant improvement in oxygenation and hemodynamic markers of perfusion, including blood pressure. Its effects begin early during the first hours of treatment.