The Relationship between Oxidative Stress, Intermittent Hypoxemia, and Hospital Duration in Moderate Preterm Infants

Abstract

<b><i>Introduction:</i></b> Lipid peroxidation products are present following oxidation of polyunsaturated fatty acids in the eye, brain, and various cell membranes. Elevated levels of lipid peroxidation products and increased intermittent hypoxemia (IH) events have been associated with adverse outcomes in extremely preterm infants. The moderate preterm newborn has a still-developing oxidant defense system and immature respiratory control, but little is known about lipid peroxidation levels and IH in this larger and more common preterm population. <b><i>Objective:</i></b> To determine the association between oxidative stress and IH in moderate preterm infants. <b><i>Method:</i></b> Oxygen saturation was continuously monitored in 51 moderate preterm infants (i.e., 31 + 0/7 to 33 + 6/7 weeks’ gestation). Urine samples were collected at the end of the first and second weeks of life. Samples were analyzed for total lipid peroxidation products (neurofurans, isofurans, neuroprostanes, isoprostanes, and di-homo-isofurans). <b><i>Result:</i></b> At week 1, there was a correlation between increased IH frequency and neurofurans (<i>p</i> < 0.04) and di-homo-isofurans (<i>p</i> < 0.003). At week 2, there was no correlation between IH and lipid peroxidation markers. Ele­vations in neurofurans, isofurans, neuroprostanes, and di-homo-isofurans in the first and/or second week of life were associated with a longer stay in hospital. <b><i>Conclusion:</i></b> Elevations in lipid peroxidation biomarkers in moderate preterm infants during their first weeks of life are associated with a higher frequency of IH and prolonged hospitalization.

Room air versus 100% oxygen for delivery room resuscitation of preterm neonates in low resource settings: A randomised, blinded, controlled trial

“…The same group studied the role of various biochemical markers of oxidative stress in moderate preterm infants and their role in the prolongation of hospitalisation. The authors reported that at 7 days of life, Isofurans, products of lipid peroxidation with a substituted tetrahydrofuran ring were significantly correlated with an increased length of hospitalisation 24 . A study by Kuligowski et al .…”

“…The authors reported that at 7 days of life, Isofurans, products of lipid peroxidation with a substituted tetrahydrofuran ring were significantly correlated with an increased length of hospitalisation. 24 A study by Kuligowski et al found that infants with higher urinary elimination of isoprostanes and isofurans in the first week of life had a higher risk of developing bronchopulmonary dysplasia later on. 25 A separate review by Torres-Cuevas I reported a correlation between the amount of oxygen received and level of biomarkers of oxidative stress and clinical outcomes.…”

Association between Intermittent Hypoxemia and NICU Length of Stay in Preterm Infants

“…For example, oxidative stress could be a mechanism linking IH events and downstream morbidities, leading to prolonged hospitalization [22][23][24][25]. Preliminary data in moderately preterm infants (31 to <34 weeks' gestation), who exhibit a low incidence of IH events, have shown a relationship between increased IH frequency and elevated urine lipid peroxidation by-products of docosahexaenoic acid and adrenic acid, which in turn were associated with the length of stay [8]. Inflammation may be another mechanism by which IH could lead to the need for prolonged hospitalization, such as through the development of BPD [25].…”

“…Some maternal and neonatal factors, such as maternal hypertension, lower birth weight, infant sex, sepsis, and other clinical markers of severity of illness, have been associated with prolonged length of stay [2][3][4][5][6]. Emerging data indicate physiological instability manifesting as intermittent hypoxemia (IH) may also be associated with length of stay [7,8].…”

Room air versus 100% oxygen for delivery room resuscitation of preterm neonates: A randomized, blinded, controlled trial

“…The same group studied the role of various biochemical markers of oxidative stress in moderate preterm infants and their role in the prolongation of hospitalization. The authors reported that at 7 days of life, Isofurans, products of lipid peroxidation with a substituted tetrahydrofuran ring, and not Isoprostane was signi cantly correlated with increased length of hospitalization (33).…”