Author’s reply to the correspondence letter from Dr. S. Meyer et al. entitled arginine-vasopressin as a rescue therapy in children and neonates for catecholamine-resistant shock

Abstract

We appreciate the interest in our study and the comments by Dr. Meyer and would like to respond to them. Our study reported the retrospectively analysed data of 17 neonates, who developed systemic inflammatory response syndrome (SIRS) with catecholamineresistant vasodilatory shock following open-heart surgery and were treated with lowdose continuous infusion of arginine-vasopressin (AVP). Despite the use of modified ultrafiltration uncontrolled release of proinflammatory cytokines may lead to SIRS after cardiopulmonary bypass. Especially neonates who undergo cardiac surgery with long bypass duration are at high risk to develop post bypass SIRS [2, 7]. This syndrome is not necessarily associated with cardiac dysfunction or cardiogenic shock. Both septic as well as post cardiopulmonary bypass-induced severe vasodilatation are associated with inappropriately low vasopressin plasma levels; so this vasopressin deficiency may contribute to the hypotension of vasodilatory shock [3, 4, 6]. Low dose continuous infusions of vasopressin have been successfully used in several trials in adults and children with vasodilatory shock secondary to open-heart surgery [1, 5, 6]. In accordance with these findings, our study showed that in neonates with vasodilatory shock refractory to traditional vasopressors after cardiac surgery vasopressin seems to be a potent agent to increase blood pressure and avoid end-organ failure. Because vasopressin is less appropriate for neonates with ventricular dysfunction [6], we took care not to use AVP in patients with cardiac dysfunction. One major limitation of our study was that we did not measure endogenous vasopressin levels prior to the initiation of AVP. We fully agree with the suggestion of Dr. Meyer that future clinical studies should assess endogenous vasopressin levels prior to the administration of exogenous AVP.