Outcomes of oxygen saturation targeting during delivery room stabilisation of preterm infants

Abstract

Objective: To determine the association between SpO2 at 5 min and preterm infant outcomes.

Design: Data from 768 infants <32 weeks gestation from 8 randomised controlled trials (RCTs) of lower (≤0.3) versus higher (≥0.6) initial inspiratory fractions of oxygen (FiO2) for resuscitation, were examined.

Setting: Individual patient analysis of 8 RCTs INTERVENTIONS: Lower (≤0.3) versus higher (≥0.6) oxygen resuscitation strategies targeted to specific predefined SpO2 before 10 min of age.

Patients: Infants <32 weeks gestation.

Main outcome measures: Relationship between SpO2 at 5 min, death and intraventricular haemorrhage (IVH) >grade 3.

Results: 5 min SpO2 data were obtained from 706 (92%) infants. Only 159 (23%) infants met SpO2 study targets and 323 (46%) did not reach SpO280%. Pooled data showed decreased likelihood of reaching SpO280% if resuscitation was initiated with FiO2 <0.3 (OR 2.63, 95% CI 1.21 to 5.74, p<0.05). SpO2 <80% was associated with lower heart rates (mean difference -8.37, 95% CI -15.73 to -1.01, *p<0.05) and after accounting for confounders, with IVH (OR 2.04, 95% CI 1.01 to 4.11, p<0.05). Bradycardia (heart rate <100 bpm) at 5 min increased risk of death (OR 4.57, 95% CI 1.62 to 13.98, p<0.05). Taking into account confounders including gestation, birth weight and 5 min bradycardia, risk of death was significantly increased with time taken to reach SpO280%.

Conclusion: Not reaching SpO280% at 5 min is associated with adverse outcomes, including IVH. Whether this is because of infant illness or the amount of oxygen that is administered during stabilisation is uncertain and needs to be examined in randomised trials.

Keywords: neonatology; resuscitation.

Conflict of interest statement

Competing interests: None declared.

© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Figures

Figure 1

Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram.

Figure 2

5 min SpO2 for infants given initial FiO2 <0.3 or >0.6. (A) Number of infants in each group with SpO280%, (B) time to reach SpO2 >80%, (C) mean difference in SpO2at 5 min.

Figure 3

Heart rate (HR) differences between infants with SpO2 </>80% at 5 min. (A) Infants with HR <100 bpm at 5 min, (B) mean HR at 5 min.

Figure 4

Risks of death, intraventricular haemorrhage and bronchopulmonary dysplasia in infants with 5 min SpO2</>80%.

Figure 5

Cumulative risk of death with time taken to reach SpO2 80%. Note higher risk of death in infants with heart rates <100 bpm at 5 min (also see table 5 for HRs associated with each confounder).