The use of Arginine Vasopressin in neonates following the Norwood procedure

Abstract
Following the Norwood palliation, neonates may require an escalation of inotropic and vasoactive support. Arginine Vasopressin may be uniquely useful in supporting this population. A retrospective evaluation of neonates at this institution between November, 2007 and October, 2010 who received Arginine Vasopressin following the Norwood procedure. Data were recorded from the patient records at one hour prior to, and then 1, 2, 3, 4, 6, and 24 hours following Arginine Vasopressin initiation. We included 28 neonates. The mean dose of Arginine Vasopressin was 0.0005 plus or minus 0.0003 units per kilogram per minute. There was an early response (less than 6 hours) characterised by an 8% increase in systolic blood pressure (p = 0.0004), a 100% increase in urine output (p = 0.02), and a 29% decrease in total fluid administration (p = 0.04). The late response (at 24 hours) revealed further increases in systolic blood pressure and urine output as well as a 53% decrease in serum lactate (p = 0.007) and increase in arterial pH from 7.36 to 7.45 (p less than 0.0001). These changes were not accompanied by increases in heart rate or inotrope score. The initiation of Arginine Vasopressin in post-operative Norwood patients was temporally associated with an improvement in markers of perfusion including systolic blood pressure, urine output, lactate, and pH. Further studies are required to ascertain the efficacy of Arginine Vasopressin in this population.