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

Abstract

Abstract Objective. The aim of our study is to describe the effects of vasopressin on term infants with persistent pulmonary hypertension under a standardized protocol. Study Design: In 2019, we designed a standardized protocol for the management of refractory hypotension in the context of pulmonary hypertension, which included the use of vasopressin. This is a retrospective cohort study to evaluate the clinical, laboratory, and echocardiographic outcomes of patients who required vasopressin in the context of this new protocol in a referral level IV neonatal intensive care unit. Results: We included 48 neonates with a median gestational age of 37 weeks in a period of 30 months (December 2019 to May 2022). Congenital diaphragmatic hernia was the main cause of persistent pulmonary hypertension in this cohort (82%). All patients were on mechanical ventilation and receiving inhaled nitric oxide. In our cohort at 4 hours after initiation of vasopressin, blood pressure, serum pH, and urinary output increased significantly. The vasoactive inotropic score, lactate and oxygenation index decreased. Echocardiographic follow-up also showed a decrease in the relative pressure of the right ventricle and an improvement in the cardiac output of both ventricles. There were no episodes of severe hyponatremia (<120 mmol/L). Discussion: This study showed that the use of vasopressin in neonates with persistent pulmonary hypertension and refractory systemic hypotension was associated with a rapid and significant improvement in oxygenation and hemodynamic markers of perfusion, including blood pressure. This association was early during the first hours of treatment and vasopressin was safely withdrawn after a median of 3 days of treatment.