Vasopressin as a Rescue Therapy for Refractory Pulmonary Hypertension in Neonates: Case Series

Objectives: To determine the effect of vasopressin therapy on the efficacy of oxygenation and arterial pressure in infants with severe persistent pulmonary hypertension of the newborn. Design: Retrospective case study. Setting: Neonatal ICU, Hospital for Sick Children, Toronto, Canada. Subjects: Neonates with severe persistent pulmonary hypertension. Intervention: Intravenous infusion of vasopressin. Measurements and Main Results: Ten infants satisfied the inclusion criteria. Inhaled nitric oxide was used for median (interquartile range) duration of 15 hours (11-28 hr) prior to vasopressin commencement. Vasopressin was initiated at a mean dose of 0.0002 0.0002 U/kg/min for a median (interquartile range) duration of 49 hours (13-95 hr). Administration of vasopressin was associated with an improvement in oxygenation index, peak effect 6 hours after drug initiation (p = 0.01), and a reduction in inhaled nitric oxide dose (p < 0.05). There was a concomitant improvement in blood pressure (p < 0.05) and urine output (p < 0.05), without drop in the serum sodium level or worsening in serum lactate level. Conclusions: Although there is limited experience of vasopressin use in persistent pulmonary hypertension of the newborn infants, our case series suggests it to be a potential adjunctive therapy for improving the efficacy of oxygenation and systemic hypotension. A prospective randomized trial is needed to confirm its efficacy and safety in the management of severe persistent pulmonary hypertension of the newborn.