Splanchnic and Renal Tissue Oxygenation During Enteral Feedings in Neonates With Patent Ductus Arteriosus

Study Overview
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Brief Summary
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Patent ductus arteriosus (PDA) is a common problem in the neonatal intensive care unit and can be secondary to prematurity or congenital heart disease (CHD). PDA is the most common cardiovascular abnormality in preterm infants, and is seen in 55% of infants born at 28 weeks, and 1000 grams or less. In addition to producing heart failure and prolonged respiratory distress or ventilator dependence, PDA has been implicated in development of broncho-pulmonary dysplasia, interventricular hemorrhage, cerebral ischemia, and necrotizing enterocolitis (NEC). In an Israeli population study 5.6% of all very low birth weight infants (VLBW) were diagnosed with NEC, and 9.4% of VLBW infants with PDA were found to have NEC. In a retrospective analysis of neonates with CHD exposed to Prostaglandin E found that the odds of developing NEC increased in infants with single ventricle physiology, especially hypoplastic left heart syndrome. The proposed pathophysiological explanation of NEC and PDA is a result of diastolic steal where blood flows in reverse from the mesenteric arteries back into the aorta leading to compromised diastolic blood flow and intestinal hypo-perfusion. Prior studies have demonstrated that infants with a hemodynamically significant PDA have decreased diastolic flow velocity of the mesenteric and renal arteries when measured by Doppler ultrasound, and an attenuated intestinal blood flow response to feedings in the post prandial period compared to infants without PDA. Near Infrared Spectroscopy (NIRS) has also been used to assess regional oxygen saturations (rSO2) in tissues such as the brain, kidney and mesentery in premature infants with PDA. These studies demonstrated lower baseline oxygenation of these tissues in infants with hemodynamically significant PDA. These prior NIRS studies evaluated babies with a median gestational age at the time of study of 10 days or less. It is unknown if this alteration in saturations will persist in extubated neonates with PDA at 12 or more days of life on full enteral feedings. In the present study the investigators hypothesize that infants with a PDA, whether secondary to prematurity or ductal dependent CHD, will have decreased splanchnic and renal perfusion and rSO2 renal/splanchnic measurements will be decreased during times of increased metabolic demand such as enteral gavage feeding. To test this hypothesis the investigators have designed a prospective observational study utilizing NIRS to record regional saturations at baseline, during feedings, and after feedings for 48 hours.

Official Title
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Splanchnic and Renal Tissue Oxygenation During Enteral Feedings in Neonates With Patent Ductus Arteriosus

Conditions
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Infant, Premature, Congenital Heart Disease, Patent Ductus Arteriosus, Necrotizing Enterocolitis

Intervention / Treatment
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* Procedure: Near-infrared spectroscopy (NIRS)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: PDA secondary to prematurity Premature infants of ≤ 32 weeks gestational age at birth Patent ductus arteriosus diagnosed via echocardiogram Feeding volume ≥ 70 ml/kg/day Stable Clinical Condition (no vasopressors, no clinical sepsis) Age ≥ 12 days of life Control group Premature infants of ≤ 32 weeks gestational age at birth No PDA Feeding volume ≥ 70 ml/kg/day Stable Clinical Condition (no vasopressors, no clinical sepsis) Age ≥ 12 days of life PDA secondary to CHD and Prostaglandin E (PGE) Infants of ≥ 32 weeks gestational age at birth Ductal dependant congenital heart disease PGE infusion No prior cardiac surgery Any bolus feedings 10 ml/kg/day or more Stable Clinical Condition (no vasopressors, no clinical sepsis) Age ≥ 12 days of life Control Group Infants of ≥ 32 weeks gestational age at birth No know congenital heart defect including PDA. No prior cardiac surgery Feeding volume ≥ 1/2 of total fluid volume  50- 70 ml/kg/day Stable Clinical Condition (no vasopressors, no clinical sepsis) Exclusion Criteria: Lack of parental consent Multiple congenital anomalies Unstable clinical condition Prior abdominal pathology (medical/surgical necrotizing enterocolitis within the last 14 days, gastroschisis, or other abdominal abnormality)

Ages Eligible for Study
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Minimum Age: 12 Days
Maximum Age: 6 Months

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Preterm, no PDA<br>Babies </= 32 weeks gestation at birth with no symptoms of a patent ductus arteriosus (PDA) or echocardiogram confirmation of no PDA Near-infrared spectroscopy (NIRS) monitoring x 48 hours of splanchnic and cranial regions, minimum of 8 feedings need to be recorded | Procedure: Near-infrared spectroscopy (NIRS)<br>* NIRS analyzes regional oxygen saturations (rSO2)<br>|
| Preterm, moderate to large PDA<br>Babies </= 32 weeks gestation at birth with confirmed moderate to large PDA on echocardiogram Near-infrared spectroscopy (NIRS) monitoring x 48 hours of splanchnic and cranial regions, minimum of 8 feedings need to be recorded | Procedure: Near-infrared spectroscopy (NIRS)<br>* NIRS analyzes regional oxygen saturations (rSO2)<br>|
| >/= 34 wk infants, no CHD<br>Babies >/= to 34 weeks gestation at birth with no evidence of ductal dependent congenital heart disease (CHD) Near-infrared spectroscopy (NIRS) monitoring x 48 hours of splanchnic, renal and cranial regions, minimum of 8 feedings need to be recorded | Procedure: Near-infrared spectroscopy (NIRS)<br>* NIRS analyzes regional oxygen saturations (rSO2)<br>|
| >/= 34 week infants, CHD<br>Babies >/= to 34 weeks gestation at birth with ductal dependent CHD Near-infrared spectroscopy (NIRS) monitoring x 48 hours of splanchnic, renal and cranial regions, minimum of 8 feedings need to be recorded | Procedure: Near-infrared spectroscopy (NIRS)<br>* NIRS analyzes regional oxygen saturations (rSO2)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Baseline renal and splanchnic rSO2 measurements | Compare the baseline renal and splanchnic rSO2 measurements between preterm, late preterm, and term infants with a patent ductus arteriosus to those infants without a patent ductus arteriosus | 48 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Renal and splanchnic rSO2 measurements during feedings | Compare the renal and splanchnic rSO2 measurements between preterm, late preterm, and term infants with a patent ductus arteriosus to those infants without a patent ductus arteriosus immediately before, during, and after feedings | 48 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Near-infrared spectroscopy (NIRS), renal oxygen saturations, splanchnic oxygen saturations