Resuscitation of Preterm Infants with Reduced Oxygen Results in Less Oxidative Stress than Resuscitation with 100% Oxygen

Abstract

Summary The objective of this study was to determine the effects of the level of inhaled oxygen during resuscitation on the levels of free radicals and anti-oxidative capacity in the heparinized venous blood of preterm infants. Forty four preterm infants <35 weeks of gestation with mild to moderate neonatal asphyxia were randomized into two groups. The first group of infants were resuscitated with 100% oxygen (100% O2 group), while in the other group (reduced O2 group), the oxygen concentration was titrated according to pulse oximeter readings. We measured total hydroperoxide (TH) and redox potential (RP) in the plasma within 60 min of birth. The integrated excessive oxygen (∑(FiO2-0.21) × Time(min)) was higher in the 100% O2 group than in the reduced O2 group (p<0.0001). TH was higher in the 100% O2 group than in the reduced O2 group (p<0.0001). RP was not different between the 100% O2 and reduced O2 groups (p = 0.399). RP/TH ratio was lower in the 100% O2 group than in the reduced O2 group (p<0.01). We conclude that in the resuscitation of preterm infants with mild to moderate asphyxia, oxidative stress can be reduced by lowering the inspired oxygen concentration using a pulse oximeter.

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).…”

Delivery room resuscitation of preterm infants in Canada: current practice and views of neonatologists at level III centers

“…Close to one third of responders start resuscitation with a delivered oxygen concentration of 30 to 50%, a practice that is supported by some recent small randomized controlled trials despite the fact these trials were not sufficiently powered to evaluate the impact on long-term outcome. [19][20][21][22] There is likely to be clinical equipoise until new evidence is provided or the recommendation is further modified. It is worth noting that 10% of respondents still use 100% oxygen to initiate resuscitation, which may induce hyperoxia and oxidative stress-mediated end-organ damage.…”

“…It is worth noting that 10% of respondents still use 100% oxygen to initiate resuscitation, which may induce hyperoxia and oxidative stress-mediated end-organ damage. 22 Most physicians reported having sufficient resources to monitor oxygen saturation and control supplemental oxygen concentration by using pulse oximeters and oxygen blenders. The uncertainty surrounding the normal physiological rate of increasing oxygen saturation or the ultimate safe range of saturation in VLBW infants during their first minutes of life relates to the lack of current evidence.…”

Why are we still using oxygen to resuscitate term infants?

“…48 In addition, preterm infants <35 weeks of gestation in need of resuscitation had evidence of lower levels of oxidative stress when FiO 2 was titrated according to pulse oximetry than when 100% O 2 was used. 49 From the emerging data it seems that an FiO 2 of 1.0 or 0.9 is too high for preterm infants in need of stabilization/ resuscitation at birth, whereas 0.21, in many cases, is too low. However, an FiO 2 of 0.3 seems to be sufficient in most cases for the initiation of the resuscitation process and might result in fewer complications than starting with an FiO 2 of 0.9.…”