Dose-response Study of Sodium Nitroprusside in Children Requiring Controlled Hypotension in the Operating Room

The trial is a multicenter randomized, double-blind, parallel group, dose-ranging, effect-controlled study examining the effects of sodium nitroprusside in pediatric subjects requiring relative hypotension during a surgical or medical procedure. The goal is to establish the starting and maximum infusion rates that afford optimum blood pressure control in children and a safe dosing regimen in children. The objective is to describe the relationship between the infusion rate of nitroprusside and changes in blood pressure. The specific aims of this trial are: 1. To define the onset and offset of blood pressure lowering effects of nitroprusside to obtain adequate instructions for dose titration in the pediatric population. 2. To construct a dose-response model that defines the relationship between nitroprusside infusion rate and changes in blood pressure in pediatric subjects. 3. To assess the safety of nitroprusside administration in pediatric subjects requiring controlled reduction of blood pressure.