Resuscitation of preterm neonates with limited versus high oxygen strategy

Abstract

Objective: To determine whether a limited oxygen strategy (LOX) versus a high oxygen strategy (HOX) during delivery room resuscitation decreases oxidative stress in preterm neonates.

Methods: A randomized trial of neonates of 24 to 34 weeks' gestational age (GA) who received resuscitation was performed. LOX neonates received room air as the initial resuscitation gas, and fraction of inspired oxygen (Fio2) was adjusted by 10% every 30 seconds to achieve target preductal oxygen saturations (Spo2) as described by the 2010 Neonatal Resuscitation Program guidelines. HOX neonates received 100% O2 as initial resuscitation gas, and Fio2 was adjusted by 10% to keep preductal Spo2 at 85% to 94%. Total hydroperoxide (TH), biological antioxidant potential (BAP), and the oxidative balance ratio (BAP/TH) were analyzed in cord blood and the first hour of life. Secondary outcomes included delivery room interventions, respiratory support on NICU admission, and short-term morbidities.

Results: Forty-four LOX (GA: 30 ± 3 weeks; birth weight: 1678 ± 634 g) and 44 HOX (GA: 30 ± 3 weeks; birth weight: 1463 ± 606 g) neonates were included. LOX decreased integrated excess oxygen (∑Fio2 × time [min]) in the delivery room compared with HOX (401 ± 151 vs 662 ± 249; P < .01). At 1 hour of life, BAP/TH was 60% higher for LOX versus HOX neonates (13 [9-16] vs 8 [6-9]) µM/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).

Conclusions: LOX is feasible and results in less oxygen exposure, lower oxidative stress, and decreased respiratory morbidities and thus is a reasonable alternative for resuscitation of preterm neonates in the delivery room.

Trial registration: ClinicalTrials.gov NCT01697904.

Keywords: newborn; oxidative stress; oxygen; preterm; resuscitation.

FIGURE 1

Flow diagram showing screening of eligible infants, enrollment, and randomization.

FIGURE 2

A, Median level of O₂ administered per minute of life for the first 10 minutes of life in preterm neonates randomly assigned to the LOX group, in which initial Fio₂ after birth was 21%, or the HOX group, in which initial Fio₂ after birth was 100%. * P < .05. B, Median Spo₂ per minute of life for first 10 minutes of life in the DR in LOX and HOX infants. * P < .05.

FIGURE 3

A, Proportion of neonates with Spo₂ >94% per minute for the first 10 minutes of life in the DR in the LOX and HOX groups. * P < .05. B, Proportion of neonates with Spo₂ <10th percentile of Dawson curves for the first 10 minutes of life in the DR in the LOX and HOX groups. * P < .05.

FIGURE 4

(A) Total hydroperoxides, (B) biological antioxidant potential, and (C) oxidative balance ratio in cord blood and 1 hour of life in preterm neonates resuscitated with LOX or HOX. Data are presented as mean ± SD. Mann-Whitney test was used for comparison of difference over time (cord and admission samples) between the groups. * P < .01.