Energy Utilization in Premature Neonates Undergoing Screening for Retinopathy of Prematurity

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.

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.

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.

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.