OBJECTIVE:Vasopressin is a neuropeptide hormone which has been used clinically for more than 50 years and plays a major role in circulatory homeostasis and in the regulation of serum osmolality. Recent work has emphasized its role in the treatment of septic shock. This paper reviews the physiology of this neurohormone and the available evidence in favor of its use as a vasodilator for children in shock. SOURCES: MEDLINE, using the terms vasopressin, vasodilation, shock and septic shock, plus synonyms and related terms. Classic publications on the topic were also reviewed and selected depending on their relevance to the study objectives. SUMMARY OF THE FINDINGS: Vasopressin is synthesized in the neurohypophysis and released in response to a decrease in plasma volume or an increase in serum osmolality. The action of vasopressin is mediated by the activation of oxytocin receptors and of several G protein-coupled receptors, which are classified according to their location and intracellular transmission routes as V1 receptors (or V1b), V2 and V3 receptors (or V1b). The main role of vasopressin is to induce vasoconstriction. However, in certain organs, it can also induce selective vasodilation. Several clinical studies in adults and children have reported that the effects of vasopressin for the treatment of vasodilatory septic shock, due to a variety of causes, are both beneficial and safe. CONCLUSIONS: The evidence is restricted. Most studies are retrospective and include a small number of patients. Nevertheless, there is significant experience concerning the use of vasopressin in Pediatrics. Vasopressin has a beneficial clinical effect in children and can be indicated in the treatment of refractory vasodilatory shock, after adequate volume resuscitation and when high doses of other vasopressors are not effective.
Shock; vasodilation; vasopressors; vasopressin; pediatric intensive care; children