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Transcutaneous Microcirculatory Imaging in Preterm Neonates
Published on: December 31, 2015
Energy Utilization in Premature Neonates Undergoing Screening for Retinopathy of Prematurity
Alena M Pentecost1, Danilo S Boskovic2,3, Alexis Antimo1
1Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350, USA.
Insights
Retinopathy of prematurity (ROP) screening exams may increase energy use in premature infants, indicated by elevated uric acid-to-creatinine ratios. Neonates on oxygen support experienced more severe oxygen desaturations post-exam.
Area of Science:
- Neonatal care
- Ophthalmology
- Biochemistry
Background:
- Premature neonates undergo frequent retinopathy of prematurity (ROP) screening exams.
- These exams cause pain and may impact energy utilization and cellular hypoxia.
- The effect of supplemental oxygen on these outcomes is unclear.
Purpose of the Study:
- To investigate the impact of ROP screening on urinary uric acid-to-creatinine ratios ([UA]/[Cr]) as a marker of ATP degradation and hypoxia.
- To assess the effect of ROP screening on clinically significant events in premature neonates.
- To determine if supplemental oxygen influences these effects.
Main Methods:
- Prospective pilot study in a NICU setting.
- Measured urinary [UA]/[Cr] using high-performance liquid chromatography.
- Analyzed clinical events (apnea, bradycardia, gastric residuals, oxygen desaturations) via chart review.
- Compared neonates on room air (n=18) versus oxygen support (n=20).
Main Results:
- Urinary [UA]/[Cr] levels were significantly higher 0-12 and 12-24 hours post-exam, indicating increased energy utilization and potential stress.
- Neonates receiving oxygen support experienced significantly more total and severe oxygen desaturations post-exam.
Conclusions:
- ROP screening may increase energy utilization in premature neonates.
- Neonates on oxygen support are more vulnerable to post-exam oxygen desaturations.
- Further research is needed to mitigate the stress of ROP screening.
Background/Objectives:
Premature neonates are at risk for retinopathy of prematurity (ROP) and routinely undergo screening exams that involve substantial physical manipulation, often causing significant signs of pain, despite pain-relieving interventions. It remains unclear whether these exams affect energy utilization, cellular hypoxia, and clinically significant events, and whether receiving supplemental oxygen affects these relationships. This work examines the effects of ROP screening on (1) urinary uric acid-to-creatinine concentration ratios ([UA]/[Cr]), a known marker of ATP degradation, hypoxia, and oxidative stress; and (2) clinically significant events (apnea, bradycardia, gastric residuals, and oxygen desaturations) in premature neonates on room air or oxygen support.
Methods:
This prospective pilot study included premature neonates requiring ROP screening examinations at Loma Linda University's NICU. Urinary [UA]/[Cr], measured by high-performance liquid chromatography, and clinical events, documented by prospective medical chart review, were analyzed pre- and post-exam in subjects on room air (n = 18) or on oxygen support (n = 20). Statistical analyses included a generalized linear mixed model for urinary [UA]/[Cr] and Wilcoxon signed rank tests for clinical events.
Results:
A significant time effect (p = 0.010) was observed for urinary [UA]/[Cr], with higher levels at 0-12 (p = 0.023) and 12-24 (p = 0.023) hours post-exam. Subjects receiving oxygen support had more total (p = 0.028) and more severe (p = 0.026) oxygen desaturations.
Conclusions:
ROP examinations may increase energy utilization in premature neonates, with those receiving oxygen support being particularly susceptible to oxygen desaturations post-exam. Further research is needed to clarify the full impact of the procedure and to identify strategies to minimize stress associated with these screening examinations.

