Measuring Oxygenation in Newborn Infants with Targeted Oxygen Ranges (MONITOR): a randomised crossover pilot study.

Objective: The Neonatal Oxygenation Prospective Meta-analysis (NeOProM) Collaboration showed that high (91-95%) versus low (85-89%) SpO ₂ targets reduced mortality. Trials of higher targets are needed to determine whether any more survival advantage may be gained. This pilot study explored the achieved oxygenation patterns observed when targeting SpO ₂ 92-97% to facilitate the design of future trials.
Design: Single-centre prospective randomised crossover pilot study. Manual FiO ₂ adjustment. Study time 12 hours per infant. 6 hours targeting SpO ₂ 90-95% and 6 hours targeting SpO ₂ 92-97%.
Patients: Twenty preterm infants born <29 weeks' gestation, greater than 48 hours old, receiving supplemental oxygen.
Outcomes: Primary outcome was percentage time with SpO ₂ above 97% and below 90%. Pre-defined secondary outcomes included percentage time spent within, above or below transcutaneous PO ₂ (TcPO ₂ ) 6.7-10.7 kPa (50-80 mm Hg). Comparisons were made using paired-samples t-test (2-tailed).
Results: With SpO ₂ target 92-97% versus 90-95%, the mean (IQR) percentage time above SpO ₂ 97% was 11.3% (2.7-20.9) versus 7.8% (1.7-13.9), p=0.02. Percentage time with SpO ₂ <90% was 13.1% (6.7-19.1) versus 17.9% (11.1-22.4), p=0.003. Percentage time with SpO ₂ <80% was 1% (0.1-1.4) versus 1.6% (0.4-2.6), p=0.119. Percentage time with TcPO ₂ <6.7 kPa (50 mm Hg) was 49.6% (30.2-66.0) versus 55% (34.3-73.5), p=0.63. Percentage time above TcPO ₂ 10.7 kPa (80 mm Hg) was 1.4% (0-1.4) versus 1.8% (0-0), p=0.746.
Conclusions: Targeting SpO ₂ 92-97% produced a right shift in SpO ₂ and TcPO ₂ distribution, with reduced time at SpO ₂ <90% and increased time at SpO ₂ >97%, without increasing time with TcPO ₂ >10.7 kPa (80 mm Hg). Clinical trials targeting this higher SpO ₂ range could be conducted without significant hyperoxic exposure.
Trial Registration Number: NCT03360292.
Competing Interests: Competing interests: None declared.
(© Author(s) (or their employer(s)) 2023. No commercial re-use. See rights and permissions. Published by BMJ.)