L-citrulline for Prevention of Sequelae of Acute Lung Injury in Pediatrics Undergoing Cardiopulmonary Bypass for Heart Defects

Study Overview
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Brief Summary
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The purpose of this study is to determine whether L-citrulline is effective and safe in the prevention of clinical sequelae of Acute Lung Injury in pediatric subjects undergoing surgery for congenital heart defects.

Detailed Description
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This is a randomized, double-blind, placebo controlled, multicenter study that will compare the efficacy and safety of L-citrulline versus placebo in subjects undergoing surgery for congenital heart defects. Eligible subjects undergoing repair of a large unrestrictive ventricular septal defect (VSD), a partial or complete atrioventricular septal defect (AVSD), or an ostium primum atrial septal defect (primum ASD) will be eligible for enrollment in this study. Each enrolled subject will be randomized to receive either L-citrulline or placebo throughout all administrations in the study. Subjects will receive an L-citrulline bolus of 150 mg/kg or placebo at the initiation of cardiopulmonary bypass, the addition of L-citrulline at a concentration of 200 μmol/L or placebo given as a bolus during bypass. This may be administered as a one-time bolus or multiple administrations to compensate for fluids containing L-citrulline that may be removed from the patient during the course of the operation and thus to maintain the concentration of 200 μmol/L. L-citrulline bolus of 20 mg/kg or placebo 30 minutes after decannulation from cardiopulmonary bypass, followed immediately by a 9 mg/kg/hr continuous L-citrulline infusion or placebo for up to 48 hours. The study drug or placebo infusion will be discontinued once invasive arterial blood pressure monitoring is discontinued or at 48 hours, whichever comes first. Subjects will be followed until Day 28 or discharge from the hospital, whichever comes first. For subjects discharged prior to Day 28, a final assessment via telephone will be conducted at Day 28.

Official Title
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A Phase III Double-Blind, Randomized, Placebo Controlled, Multi-Center Clinical Study to Evaluate the Efficacy and Safety of Intravenous L-citrulline for the Prevention of Clinical Sequelae of Acute Lung Injury Induced by Cardiopulmonary Bypass in Pediatric Subjects Undergoing Surgery for Congenital Heart Defects

Conditions
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Acute Lung Injury

Intervention / Treatment
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* Drug: L-citrulline
* Other: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects, parents, or legal guardian of the subject who are willing and able to sign informed consent Male and female subjects aged ≤18 years of age Infants, children and adolescents undergoing cardiopulmonary bypass (CPB) for repair of a large unrestrictive VSD, an ostium primum ASD, or a partial or complete AVSD Pre-operative echocardiogram which confirms the cardiovascular anatomy and defect to be surgically repaired Exclusion Criteria: Evidence of pulmonary artery or vein abnormalities on the pre-operative echocardiogram that will not be addressed surgically. Specific abnormalities excluded include the following: Significant pulmonary artery narrowing not amenable to surgical correction Previous pulmonary artery stent placement Significant left sided AV valve regurgitation not amenable to surgical correction Pulmonary venous return abnormalities not amenable to surgical correction Pulmonary vein stenosis not amenable to surgical correction Preoperative requirement for mechanical ventilation or intravenous inotrope support Presence of fixed or idiopathic pulmonary hypertension (i.e. Eisenmenger's Syndrome) prior to surgical repair Pre-operative use of medications to treat pulmonary hypertension Pregnancy; Females of child-bearing potential must be willing to participate an acceptable method of birth control for the duration of study participation (e.g. oral contraceptive, hormonal implant, intra-uterine device) Any condition which, in the opinion of the investigator, might interfere with the study objectives Participation in another clinical trial within 30 days of Screening or while participating in the current study, including the 28 days of follow-up post study drug administration

Ages Eligible for Study
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Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: L-citrulline<br>Bolus of 150 mg/kg at the initiation of cardiopulmonary bypass, but after removal of any crystalloid base; Addition of study medication at a concentration of 200 μmol/L given as a bolus during bypass. This may be administered as a one-time bolus or multiple administrations to compensate for fluids containing L-citrulline that may be removed from the patient during the course of the operation and thus to maintain the concentration of 200 μmol/L; Bolus of 20 mg/kg 30 minutes after decannulation from cardiopulmonary bypass; 9 mg/kg/hr continuous infusion for up to 48 hours. | Drug: L-citrulline<br>* Bolus of 150 mg/kg at the initiation of cardiopulmonary bypass, but after removal of any crystalloid base; Addition of study medication at a concentration of 200 μmol/L given as a bolus during bypass. This may be administered as a one-time bolus or multiple administrations to compensate for fluids containing L-citrulline that may be removed from the patient during the course of the operation and thus to maintain the concentration of 200 μmol/L; Bolus of 20 mg/kg 30 minutes after decannulation from cardiopulmonary bypass; 9 mg/kg/hr continuous infusion for up to 48 hours.<br>|
| Placebo Comparator: Placebo<br>Bolus of 150 mg/kg at the initiation of cardiopulmonary bypass; Addition of placebo matched for volume given as a bolus during bypass. This may be administered as a one-time bolus or multiple administrations during bypass; Bolus of 20 mg/kg 30 minutes after decannulation from cardiopulmonary bypass; 9 mg/kg/hr continuous infusion for up to 48 hours. | Other: Placebo<br>* Bolus of 150 mg/kg at the initiation of cardiopulmonary bypass; Addition of placebo matched for volume given as a bolus during bypass. This may be administered as a one-time bolus or multiple administrations during bypass; Bolus of 20 mg/kg 30 minutes after decannulation from cardiopulmonary bypass; 9 mg/kg/hr continuous infusion for up to 48 hours.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| A Composite Variable Consisting of the Longer of Either (1) Length of Time on Mechanical Ventilation or (2) Length of Inotrope Use. | Mechanical ventilation (MV) = invasive or noninvasive MV incl. bilevel (biphasic) positive airway pressure or continuous positive airway pressure. Inotrope use = medications considered within the derivation of total inotrope score (dopamine, dobutamine, milrinone, epinephrine, phenylephrine, norepinephrine). Both measures recorded until earliest of subject hospital discharge or Day 28. | 28 Days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Length of Time on Mechanical Ventilation | The same definitions and analyses as described for the primary endpoint will be applied. | 28 Days | 
| Length of Time on Positive Pressure Ventilation | The same definitions and analyses as described for the primary endpoint will be applied. | 28 Days | 
| Length of Time of Inotrope Use | The same definitions and analyses as described for the primary endpoint will be applied. | 28 days | 
| Inotrope Score | Inotrope score is reflective of the pharmacological support required by the cardiovascular system and is a good predictor of mortality and morbidity in patients undergoing bypass surgery. A lower inotrope score represents less pharmacological support and would indicate a lower risk for a poor clinical outcome. Therefore, any treatment effect would be indicated by a lower inotrope score in the citrulline group when compared to the placebo group. In this study, the score was calculated each hour post-operatively from the time of separation from bypass until the completion of study drug. Additionally, the total inotrope score over time until Day 28 or hospital discharge was derived. Inotrope score was calculated using the following formula: Total inotrope score = Dopamine dose (µg/kg/min) + Dobutamine dose (µg/kg/min) + 10 * Milrinone dose (µg/kg/min) + 100 * Epinephrine dose (µg/kg/min) + 100 * Phenylephrine dose (µg/kg/min) + 100 * Norepinephrine dose (µg/kg/min). | Up to 48 hours after separation from CBP | 
| Hemodynamic Improvement: Heart Rate | Heart rate at hours 1, 2, 4, 12, 24 and 48. | 2 Days | 
| Hemodynamic Improvement: Systemic Arterial Blood Pressure | Systemic arterial blood pressure at hours 1, 2, 4, 12, 24 and 48. | 2 Days | 
| Hemodynamic Improvement: Oxygen Saturation | Oxygen saturation at hours 1, 2, 4, 12, 24 and 48. | 2 Days | 
| Hemodynamic Improvement: Central Venous Pressure | Central venous pressure at hours 1, 2, 4, 12, 24 and 48. | 2 Days | 
| Thoracotomy Output | The thoracotomy output is defined as the total volume of chest tube drainage recorded in cc prior to discontinuation of chest intubation. The total postoperative duration (in hours) that the chest tube is used will be calculated as the time from the end of the surgery to the time the chest tube is removed. If an additional chest tube is required or reinserted (until discharge from the hospital or at Day 28) the duration that the additional chest tube was used (from time of insertion to time of removal) will be added to the time the original chest tube was used for the total postoperative duration. If a subject did not use any chest tube the duration is set to 0. As a sensitivity analysis, subjects with no use of chest tube will be excluded. For subjects who died before discharge from the hospital or before Day 28, respectively, the observed duration of chest tube drainage will be used. | 28 Days | 
| Length of Time of Intubation | The length will be derived as the time in hours from separation from CPB until discontinuation of intubation. Any duration of re-use of intubation will continue to accrue. If a subject did not use any intubation the length is set to 0. As a sensitivity analysis, subjects with no use of intubations will be excluded. For subjects who died before discharge from the hospital or before Day 28, respectively, the observed length of time on intubation will be used. As sensitivity analyses subjects who died will (1) be excluded from analysis and (2) be assigned a length of time on intubation of 28 days. For the length of time on intubation the same analyses as described for the primary endpoint will be applied. | 28 Days | 
| Length of Pediatric Intensive Care Unit (PICU) Stay | The length of PICU stay will be calculated as the total number of days postoperative until discharge from PICU. For subjects who died before discharge from PICU or before Day 28, respectively, the observed length of PICU stay will be used. As sensitivity analyses subjects who died will (1) be excluded from analysis and (2) be assigned a length of PICU stay of 28 days. For the length of PICU stay the same analyses as described for the primary endpoint will be applied. | 28 Days | 
| Length of Time on Vasodilators | Length of time on vasodilators will be measured from first use following separation from bypass, until the subject is discharged from the hospital or at Day 28. The length will be derived as the time in hours from separation from CPB until discontinuation of all vasodilators. | 28 Days | 
| Length of Hospitalization | The length of hospitalization will be calculated as the total number of days postoperative until discharge from the hospital. For subjects who died before discharge from the hospital or before Day 28, respectively, the observed length of hospitalization will be used. As sensitivity analyses subjects who died will (1) be excluded from analysis and (2) be assigned a length of hospitalization of 28 days. The same analyses as described for the primary endpoint will be applied. | 28 Days | 
| Patients With Plasma Concentrations of Citrulline | Plasma citrulline concentrations will be assessed in both treatment groups to determine the number of patients who reach the therapeutic sustained target plasma citrulline level of ≥100 μmol/L. Blood collection for assessment of plasma citrulline concentrations will be taken prior to surgery, during surgery, 30 minutes post-decannulation after CPB (prior to bolus and 5 minutes after bolus), at the specified post-operative time points (6h, 12h, 24h, 48h), and at hospital discharge or Day 28, whichever occurs first. | 28 Days | 
| Occurrence of Adverse and Serious Adverse Events | Pre-treatment adverse events and treatment adverse events will be analyzed separately. The number of affected subjects will be reported. | 28 Days | 
| Number of Patients With Refractory Hypotension | Refractory hypotension is defined as a 20% drop of mean arterial pressure (MAP) below specific age-related criteria for more than 30 minutes. The number of subjects with any refractory hypotension from end of surgery until 48 hours will be compared between groups. | 2 Days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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L-citrulline, pediatric, Lung Injury, Bypass, Heart Defects, Clinical Sequelae