Oxygenation of the Immature Infant: A Commentary and Recommendations for Oxygen Saturation Targets and Alarm Limits

Abstract

Background: For 70 years, there has been a search for the optimal oxygenation of premature infants. In spite of the lack of evidence, guidelines have successively reduced oxygenation targets during these years. Objectives: (1) To present a summary of previously published meta-analyses of 5 randomized studies (NeOProM) which tested a low (85–89%) versus a high (91–95%) oxygen saturation target the first weeks after birth on outcome of immature newborn infants. (2) To present international recommendations for oxygenation the first weeks after birth. Methods: Data were retrieved from meta-analyses and reviews of these studies. Results: Mortality and necrotizing enterocolitis (NEC) are significantly higher in patients with a low saturation target (relative risk, RR 1.16 and 1.24, respectively), while severe retinopathy of prematurity (ROP) is reduced (RR 0.74), fortunately without a change in the rate of blindness. Severe intraventricular hemorrhage, patent ductus arteriosus, and bronchopulmonary dysplasia (defined physiologically) were not significantly affected by the oxygen targets in the range of these studies. Based on these data, it is recommended that SpO₂ targets from birth to 36 weeks postconceptional age for infants < 28 weeks gestational age (GA) should be between 90 and 94% (with alarm limits of 89 and 95%), respectively. It is recommended to keep infants small for GA well oxygenated within the suggested targets avoiding fluctuations. Conclusions: The ideal oxygen saturation targets for infants < 28 weeks GA are not known. Mortality, ROP, and NEC seem to be particularly oxygen-sensitive outcome variables. The optimal oxygen saturation for premature infants > 28 weeks GA has not been carefully studied.

A survey on criteria for intubation in moderate to late preterm infants with respiratory distress

“…An animal study suggested that chronic exposure to FiO 2 > 85% results BPD phenotype 19. Forty percent of our respondents chose FiO 2 > 40% as part of their decisions for intubation, which suggests the cautious approach against using high concentration of oxygen 23. This is consistent with the recent updated European consensus guideline, which…”

European Consensus Guidelines on the Management of Respiratory Distress Syndrome – 2019 Update

“…Targeting lower saturations (85–89 vs. 91–95%) reduces risk of severe retinopathy of prematurity (ROP) but at expense of increasing mortality (relative risk [RR] 1.17; 95% confidence interval [CI] 1.04–1.31) and NEC. Recommendations have therefore remained the same, targeting saturations between 90 and 94% by setting alarm limits between 89 and 95% although it is acknowledged that ideal oxygen saturation targets are still unknown [84]. Episodes of intermittent hypoxaemia and bradycardia are associated with increased risk of late death or disability at 18 months, and these should be avoided if possible [85].…”

Stress Oximetry: Description of a Test to Determine Readiness for Discontinuing Oxygen Therapy in Infants with Chronic Lung Disease

“…In clinical practice, successful weaning of O 2 IT in infants with CLD is determined not only by the infant's ability to maintain oxygen saturations in an “acceptable” range for a “sufficient” period of time, but also by the ability to feed and demonstrate optimal growth. Furthermore, there is great variability in the SpO 2 values considered “acceptable” in US NICUs [ 48 , 49 ]. The period of time that an infant is monitored after discontinuing oxygen is similarly variable.…”