Oxygenation of the Newborn: A Molecular Approach

Abstract

In this review oxygenation and hyperoxic injury of newborn infants are described through molecular and genetic levels. Protection and repair mechanisms that may be important for a new understanding of oxidative stress in the newborn are discussed. The research summarized in this article represents a basis for the reduced oxygen supplementation and oxidative load of newborn babies, especially since the turn of the century. The mechanisms discussed may also contribute to an understanding of why hyperoxic resuscitation of the newborn may damage DNA and affect its repair, thus increasing the risk that it may be carcinogenic. Today, term babies should be resuscitated with air rather than 100% oxygen and very and extremely low birth weight infants in need of stabilization or resuscitation at birth should be administered initially 21–30% oxygen and the level should be titrated according to the response, preferably measured by pulse oximetry. In the postnatal period the oxygen saturation should be targeted low <95%; however, saturations between 85 and 89% seem to increase mortality. The optimal oxygen saturation target for these infants postnatally is still unknown.

Resuscitation of Preterm Neonates With Limited Versus High Oxygen Strategy

“…LOX decreased integrated excess oxygen (+FIO 2 3 time [min]) in the delivery room compared with HOX (401 6 151 vs 662 6 249; P , .01). At 1 hour of life, BAP/TH was 60% higher for LOX versus HOX neonates (13 [9][10][11][12][13][14][15][16] vs 8 [6][7][8][9]) mM/U.CARR, P , .01). LOX decreased ventilator days (3 [0-64] vs 8 [0-96]; P , .05) and reduced the incidence of bronchopulmonary dysplasia (7% vs 25%; P , .05).…”

Oxygen Supplementation in the Neonatal Period: Changing the Paradigm

“…Glutathione peroxidase couples H 2 O 2 reduction to H 2 O with the oxidation of glutathione to glutathione disulfide. Finally, nonenzymatic antioxidants such as reduced glutathione, vitamin C, vitamin E and β-carotene also function to protect cells from the damaging effects of ROS (for reviews see [4,6,11,12,13]). …”

“…Thereafter, a series of studies have corroborated the effectiveness of 21% O 2 for the resuscitation of asphyxiated term neonates; moreover, room air drastically reduces oxidative stress [4,6]. In 2008, Saugstad et al [34] published an updated review and meta-analysis showing that the use of 21% instead of 100% O 2 significantly reduced mortality in term newborn babies with asphyxia.…”

“…Hence, for a certain period, liberal use was recommended based on the beneficial effects of O 2 on patients with respiratory distress and, conversely, when its toxic effects (especially those on the retina) were realized, the recommendation of a drastic reduction of O 2 supplementation led to increased mortality [2,3]. In recent years, major steps towards a better understanding of O 2 metabolism [4] and the generalized use of pulse oximetry have extensively contributed to reducing O 2 -derived toxicity [5]. In this scenario, the results from a series of clinical studies in the delivery room [6] and during hospitalization [7,8] have contributed to setting the safety limits for O 2 supplementation in the neonatal period.…”

More about Surfactant, Oxygen, Caffeine and Chronic Lung Disease

“…This review dealt with the new paradigm in the use of oxygen in neonatal medicine. Máximo Vento's review dealt with the practical issues raised in Ola D. Saugstad's 4th Bengt Robertson Lecture in 2012 [1]. Since the Resair 2 study was published in the late 1990s [2], experimental and clinical research on oxygen metabolism and toxicity in the neonatal period have grown exponentially.…”