Conditions: Hypotension
Keywords: children sodium nitroprusside controlled hypotension dose-response pharmacokinetics pharmacodynamics safety efficacy
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 211
Healthy volunteers: no

Brief summary:
Sodium nitroprusside (SNP) has been approved for control of blood pressure in adults, yet there are no controlled studies in children. The purpose of this study is to determine the efficacy and safety of sodium nitroprusside in children who will be having surgery, and who require blood pressure lowering in order to decrease the amount of blood loss during their surgery.

Detailed description:
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.

Arms:
arm 1: Infusion of Sodium Nitroprusside began only after a 5-minute period of stable anesthesia or sedation (no changes in dosages). The infusion rate during the blinded study drug period was increased in a step-wise fashion to the full dose rate as follows: 5 ± 1 minutes at 1/3 of the full rate; 5 ± 1 minutes at 2/3 of the full rate; and 20 minutes at the full dose rate (ie, 30 minutes total). The full infusion rate was 0.6 mL/kg/hr; 2/3 of the full rate was 0.4 mL/kg/hr; and 1/3 of the full rate was 0.2 mL/kg/hr. After titration to the full dose of blinded study drug, blinded infusion dosage adjustments were not permitted during the blinded study drug administration period. The blinded infusion dosage continued for the 30 minutes unless clinical events demanded a change for safety reasons. arm 2: Infusion of Sodium Nitroprusside began only after a 5-minute period of stable anesthesia or sedation (no changes in dosages). The infusion rate during the blinded study drug period was increased in a step-wise fashion to the full dose rate as follows: 5 ± 1 minutes at 1/3 of the full rate; 5 ± 1 minutes at 2/3 of the full rate; and 20 minutes at the full dose rate (ie, 30 minutes total). The full infusion rate was 0.6 mL/kg/hr; 2/3 of the full rate was 0.4 mL/kg/hr; and 1/3 of the full rate was 0.2 mL/kg/hr. After titration to the full dose of blinded study drug, blinded infusion dosage adjustments were not permitted during the blinded study drug administration period. The blinded infusion dosage continued for the 30 minutes unless clinical events demanded a change for safety reasons. arm 3: Infusion of Sodium Nitroprusside began only after a 5-minute period of stable anesthesia or sedation (no changes in dosages). The infusion rate during the blinded study drug period was increased in a step-wise fashion to the full dose rate as follows: 5 ± 1 minutes at 1/3 of the full rate; 5 ± 1 minutes at 2/3 of the full rate; and 20 minutes at the full dose rate (ie, 30 minutes total). The full infusion rate was 0.6 mL/kg/hr; 2/3 of the full rate was 0.4 mL/kg/hr; and 1/3 of the full rate was 0.2 mL/kg/hr. After titration to the full dose of blinded study drug, blinded infusion dosage adjustments were not permitted during the blinded study drug administration period. The blinded infusion dosage continued for the 30 minutes unless clinical events demanded a change for safety reasons arm 4: Infusion of Sodium Nitroprusside began only after a 5-minute period of stable anesthesia or sedation (no changes in dosages). The infusion rate during the blinded study drug period was increased in a step-wise fashion to the full dose rate as follows: 5 ± 1 minutes at 1/3 of the full rate; 5 ± 1 minutes at 2/3 of the full rate; and 20 minutes at the full dose rate (ie, 30 minutes total). The full infusion rate was 0.6 mL/kg/hr; 2/3 of the full rate was 0.4 mL/kg/hr; and 1/3 of the full rate was 0.2 mL/kg/hr. After titration to the full dose of blinded study drug, blinded infusion dosage adjustments were not permitted during the blinded study drug administration period. The blinded infusion dosage continued for the 30 minutes unless clinical events demanded a change for safety reasons

Interventions: intervention 1: Nitroprusside intervention 2: Nitroprusside intervention 3: Nitroprusside intervention 4: Nitroprusside
Intervention descriptions: intervention 1: Study drug was infused via a dedicated peripheral intravenous catheter or via a dedicated lumen of a multi-orifice central venous catheter. Infusion pumps capable of reliable delivery at low infusion rates (to 0.1 mL/hr) were used.Study drug was dispensed to the sites in 2 mL vials containing 25 mg/mL of sodium nitroprusside. The pharmacist prepared and dispensed the study drug, and supplied blinded study drug for each subject according to a randomization assignment generated by the IVRS (Interactive Voice Response System). intervention 2: Study drug was infused via a dedicated peripheral intravenous catheter or via a dedicated lumen of a multi-orifice central venous catheter. Infusion pumps capable of reliable delivery at low infusion rates (to 0.1 mL/hr) were used.Study drug was dispensed to the sites in 2 mL vials containing 25 mg/mL of sodium nitroprusside. The pharmacist prepared and dispensed the study drug, and supplied blinded study drug for each subject according to a randomization assignment generated by the IVRS. intervention 3: Study drug was infused via a dedicated peripheral intravenous catheter or via a dedicated lumen of a multi-orifice central venous catheter. Infusion pumps capable of reliable delivery at low infusion rates (to 0.1 mL/hr) were used.Study drug was dispensed to the sites in 2 mL vials containing 25 mg/mL of sodium nitroprusside. The pharmacist prepared and dispensed the study drug, and supplied blinded study drug for each subject according to a randomization assignment generated by the IVRS. intervention 4: Study drug was infused via a dedicated peripheral intravenous catheter or via a dedicated lumen of a multi-orifice central venous catheter. Infusion pumps capable of reliable delivery at low infusion rates (to 0.1 mL/hr) were used.Study drug was dispensed to the sites in 2 mL vials containing 25 mg/mL of sodium nitroprusside. The pharmacist prepared and dispensed the study drug, and supplied blinded study drug for each subject according to a randomization assignment generated by the IVRS

Protocol document: