Splanchnic and Renal Tissue Oxygenation During Enteral Feedings in Neonates With Patent Ductus Arteriosus
Condition: Infant, Premature; Congenital Heart Disease; Patent Ductus Arteriosus; Necrotizing Enterocolitis
MeSH terms: Enterocolitis; Enterocolitis, Necrotizing; Heart Diseases; Heart Defects, Congenital; Ductus Arteriosus, Patent
Study type: Observational

Summary: 
      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.
    


Intervention name(s): Near-infrared spectroscopy (NIRS)
Intervention type(s): Procedure
Intervention description(s): NIRS analyzes regional oxygen saturations (rSO2)
Observational model: Cohort
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Preterm, Late preterm, and term infants
      
Keywords: Near-infrared spectroscopy (NIRS); renal oxygen saturations; splanchnic oxygen saturations