What are the target oxygen saturation levels for term and preterm neonates?

Target Oxygen Saturation Levels for Term and Preterm Neonates

For term neonates, target oxygen saturation should be 95-99%, while preterm neonates (<35 weeks) should initially be maintained at 90-95% to balance mortality risk and retinopathy of prematurity concerns. 1

Term Neonates (≥35 weeks gestation)

Initial Resuscitation

• Begin resuscitation with 21% oxygen (room air) 1
• 100% oxygen should NOT be used to initiate resuscitation as it is associated with excess mortality 1
• If bradycardia persists after 90 seconds of effective ventilation with lower oxygen concentration, increase to 100% until heart rate recovers 2

Ongoing Management

• Target oxygen saturation: 95-99% 1
• This provides a buffer zone against oxygen desaturation while staying within the physiologic range 1
• Aim for the lower end of this range (95%) to minimize potential exacerbations of chronic lung disease 1

Preterm Neonates (<35 weeks gestation)

Initial Resuscitation

• Begin with 21-30% oxygen 1, 2
• Titrate oxygen to meet the following preductal SpO₂ targets during transition after birth 2:

  Time (min)	SpO₂ Target
  1	60-65%
  2	65-70%
  3	70-75%
  4	75-80%
  5	80-85%
  10	85-95%

Ongoing Management

• For preterm infants without active ROP or peripheral avascular retina: 90-95% 1, 3
• For preterm infants with active ROP or at risk for ROP progression: 90-95% 1
  • Contrary to earlier practice that targeted lower saturations (85-89%), recent evidence suggests that higher targets (90-95%) do not increase and may even decrease risk of ROP progression 1

Clinical Considerations and Monitoring

Monitoring Approach

• Use continuous pulse oximetry to monitor oxygen saturation 2
• Make multiple determinations in various states including rest, sleep, feeding, and high activity 1
• Consider arterial blood gas measurements in infants with suspected carbon dioxide retention 1

Risk Factors Requiring Special Attention

1. Retinopathy of Prematurity (ROP):

   • Preterm infants with peripheral avascular retina (with or without active ROP) remain at risk for ROP progression 1
   • Monitor closely to avoid sustained hyperoxemia 1
   • The STOP-ROP study found no adverse effects on ROP progression with higher oxygen saturation targets (96-99%) compared to lower targets (89-94%) 1

2. Pulmonary Hypertension:

   • Higher oxygen saturation levels (95-99%) help prevent pulmonary hypertension 1
   • Cardiac catheterization studies have demonstrated that pulmonary arterial pressure is lower at higher saturation levels 1

Implementation Challenges

Practice Variation

• A European survey identified 40 different saturation ranges in use across NICUs, with the most common being 90-95% (28% of units) 4
• 81% of NICUs changed their SpO₂ limits over a 10-year period, generally increasing targets by 3-5% 4

Improving Compliance

• Implementation of clear oxygen targeting policies with regular feedback using oxygen saturation histograms can improve compliance 5
• One quality improvement study showed an increase in time spent within target range from 65.9% to 76.5% after implementing such measures 5

Evidence Quality and Controversies

• The recommendation against using 100% oxygen for resuscitation is based on evidence showing increased mortality (RR 0.73 [95% CI 0.57-0.94] favoring 21% oxygen) 1
• The Cochrane meta-analysis found that targeting lower SpO₂ (85-89%) compared to higher SpO₂ (91-95%) in extremely preterm infants increased mortality risk (RR 1.16,95% CI 1.03-1.31) 6
• The same meta-analysis showed targeting lower SpO₂ decreased the incidence of retinopathy requiring treatment (RR 0.72,95% CI 0.61-0.85) 6
• This creates a clinical trade-off between mortality risk and ROP risk that must be carefully balanced

Key Pitfalls to Avoid

1. Using 100% oxygen for initial resuscitation in any neonate (associated with increased mortality) 1
2. Failing to titrate oxygen based on continuous SpO₂ monitoring 2
3. Not recognizing that preterm infants with active ROP require careful oxygen management 1
4. Setting overly narrow alarm limits that may lead to frequent alarms and alarm fatigue 7
5. Neglecting to adjust targets based on clinical condition (e.g., pulmonary hypertension may require higher targets) 1