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We thank Dr Hewson for his interest in our paper and for raising several intriguing points that challenges current practice about the use of oxygen during the very important first minutes of life of a sick preterm infant. There are several points we would like to clarify in response to his questions.
Firstly, in our study, only 12% (n=96) of preterm infants from the 8 studies reached the recommended SpO2 range (80-85%) and not the lower limit (80%) of this range, as stated by Dr Hewson. The majority of infants were either below (46%) or above (42%) this range at 5 minutes of age.
We agree that neither hyperoxia or hypoxia, even for a few short minutes, is in the best interest of any newborn infant. We concur with Dr Hewson that the current SpO2 recommendations are not evidence-based, especially for sick preterm infants and for either improved short or long-term outcomes. Currently, most clinical practice guidelines recommend the same SpO2 targets for both term and preterm infants (1) and do not take into account, differences in physiological needs. Indeed, Dawson et al showed that even healthy preterm infants needed several minutes more than term infants to achieve SpO2 >90% (2).
We therefore suggest that caution should be exercised before any specific SpO2 target can be recommended (e.g. 90-95% as suggested by Dr Hewson) without a sufficiently large study that is designed to assess both short and long-term outcomes. Clinical practice has swung dram...
We therefore suggest that caution should be exercised before any specific SpO2 target can be recommended (e.g. 90-95% as suggested by Dr Hewson) without a sufficiently large study that is designed to assess both short and long-term outcomes. Clinical practice has swung dramatically over the last 10 years, from the use of static levels of pure oxygen without SpO2 monitoring to blending oxygen to meet SpO2 values derived from full-term, healthy infants (3). Much more information is required before we can be confident that any SpO2 or FiO2 recommendations are in the best interest of the infant, especially one that is as physiologically complex as the extremely preterm infant.
In conclusion, we agree with Dr Hewson that the practice of SpO2 targeting and FiO2 titration for preterm infant resuscitation deserves further (and urgent) study. Until such data are available, we advise caution when using oxygen during preterm infant resuscitation and that clinicians should remember to tailor their resuscitation practice to meet the needs of each infant.
1. Wilson A, Vento M, Shah PS et al. A review of international clinical practice guidelines for the use of oxygen in the delivery room resuscitation of preterm infants. Acta Paediatr. 2018;107(1):20-27.
2. Dawson JA, Kamlin CO, Vento M et al. Defining the reference range for oxygen saturation for infants after birth. Pediatrics. 2010;125(6):e1340-7.
3. No authors listed. Co-publishing of the Pediatric and Neonatal Portions of the 2015 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations and the 2015 American Heart Association Guidelines Update for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Pediatrics. 2015;136 Suppl 2:S83-7.
This study(1) of outcomes of oxygen saturation targeting during delivery room stabilisation or preterm infants, and other data indicating that low saturations are suboptimal for preterm infants requiring resuscitation should now lead to a review of the currently recommended saturation targets. The recommended graduated targets over the first few minutes are not based on evidence of improved outcomes and also add a significant degree of complexity to what is already a challenging resuscitation environment. Complexity is a contributing factor to error in health care(2) .
The authors incorrectly state that only 12% of preterm infants who were resuscitated with blended oxygen in eight RCTs reached the lower limit of expert committee SpO2 (80%) at 5 min of age. As is made clear elsewhere in the paper, over 50% of newborns reached or exceeded 80% at 5 minutes of age.
It is possible that the relatively small percentage of infants exactly hitting the saturation target zone (80 – 85%) at 5 minutes is due at least in part to the steep slope of the oxygen dissociation curve at that range of saturation. A relatively modest change in pO2 will lead to a significant change in saturation.
The physiologically goal should be to avoid hypoxia and avoid hyperoxia. Hypoxia is increasingly likely with pre-ductal saturations below 90%. Hyperoxia is readily avoided by maintaining saturations below 96% for infants in supplemental oxygen(3).
I suggest a target of 90...
I suggest a target of 90-95% pre-ductal oxygen saturation for resuscitation of the extremely low birth weight newborn from the first acquisition of a saturation signal and through to NICU admission and beyond. Targeting 90 – 95% accords with recommended management of oxygen saturations in the NICU(4) and thus has the added benefit of being familiar to clinical staff. In practice such a simplified target still leaves clinicians with decisions around titration of inspired oxygen and in particular the optimal size of each incremental step in oxygen percentage.
Optimising the titration of oxygen once a saturation target has been decided upon probably requires consideration of individual patient factors such as airway patency, ventilation adequacy, and co-morbidities.
Individual patient analysis of the study data already available may allow the individualized prediction of optimal startingFiO2 to more reliably reach the saturation target in the first few minutes.
1. Oei JL, Finer NN, Saugstad OD, et al. Outcomes of oxygen saturation targeting during delivery room stabilisation of preterm infants. Archives of Disease in Childhood - Fetal and Neonatal Edition Published Online First: 07 October 2017. doi:10.1136/archdischild-2016-312366
2. Gluck PA. Medical Error Theory. Obstet Gynecol Clin North Am. 2008 Mar;35(1):11-17.
3. Bornhorst B, Peter CS, Poets CF. Detection of hyperoxaemia in neonates: data from three new pulse oximeters. Arch Dis Child Fetal Neonatal Ed. 2002 Nov;87(3):F217-9
4. Martin A. Neonatal target oxygen levels for preterm infants. In UpToDate, Post, TW (Ed), UpToDate, Waltham,MA,2017.
Conflict of Interest