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Received Jan 4, 2018; Accepted Feb 18, 2018
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
1. Introduction
It is well recognized that in preterm neonates, the need for invasive mechanical ventilation (MV) is associated with the so-called ventilator-induced lung injury (VILI); thus, lung protection strategies have been intensely studied in the past 20 years. Research has focused on gentle modes of ventilation as well as in reducing oxidative stress.
Superoxide, hydrogen peroxide, and perhydroxyl radicals cause oxygen-induced lung injury, and the premature infant is notably susceptible to free radical-induced injury because antioxidant systems develop late during the gestation. Excessive hyperoxia can lead to lung inflammation, diffuse alveolar injury, progressive pulmonary damage, and death [1].
The suitable arterial saturation target in preterm neonates is unknown, but exposing them to a high concentration of oxygen is related to increased risks of retinopathy of prematurity and bronchopulmonary dysplasia (BPD). Recently published large multicenter trials have studied this issue [2].
In this pilot study, our objective was to analyze any association between the oxygen levels at blood sampling and plasma levels of interleukin- (IL-) 6, IL-1β, IL-10, IL-8, and tumor necrosis factor- (TNF-) α in preterm infants under MV in their first two days of life.
2. Methods
This prospective observational study included preterm infants ranging from 28 to 35 weeks of gestational age (GA) submitted to intubation and MV in the first 48 hours of life who were admitted to the newborn section of Hospital de Clínicas de Porto Alegre (HCPA), a tertiary referral medical center located in Southern Brazil. The Ethics Committee of HCPA approved the study, and informed consent was obtained from the patients’ guardians prior to enrollment.
The exclusion criteria were congenital infections, congenital malformations, proven sepsis or meningitis, need for intubation in the delivery room, and use of prophylactic surfactant prior to enrollment in the study.
Clinical data included gender, birth weight, GA, Score for Neonatal Acute Physiology Perinatal Extension II (SNAPPE-II) regarding the first 12 hours of life, the type of delivery, and antenatal factors such as the presence of amniorrhexis, preeclampsia, steroid use, and/or chorioamnionitis. The patients...