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

The Neonatal Oxygenation Prospective Meta-analysis (NeOProM) Collaboration showed that high (91-95%) versus low (85-89%) SpO₂ 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 SpO₂ 92-97% to facilitate the design of future trials.

Single-centre prospective randomised crossover pilot study. Manual FiO₂ adjustment. Study time 12 hours per infant. 6 hours targeting SpO₂ 90-95% and 6 hours targeting SpO₂ 92-97%.

Twenty preterm infants born <29 weeks' gestation, greater than 48 hours old, receiving supplemental oxygen.

Primary outcome was percentage time with SpO₂ above 97% and below 90%. Pre-defined secondary outcomes included percentage time spent within, above or below transcutaneous PO₂ (TcPO₂) 6.7-10.7 kPa (50-80 mm Hg). Comparisons were made using paired-samples t-test (2-tailed).

With SpO₂ target 92-97% versus 90-95%, the mean (IQR) percentage time above SpO₂ 97% was 11.3% (2.7-20.9) versus 7.8% (1.7-13.9), p=0.02. Percentage time with SpO₂ <90% was 13.1% (6.7-19.1) versus 17.9% (11.1-22.4), p=0.003. Percentage time with SpO₂ <80% was 1% (0.1-1.4) versus 1.6% (0.4-2.6), p=0.119. Percentage time with TcPO₂ <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 TcPO₂ 10.7 kPa (80 mm Hg) was 1.4% (0-1.4) versus 1.8% (0-0), p=0.746.

Targeting SpO₂ 92-97% produced a right shift in SpO₂ and TcPO₂ distribution, with reduced time at SpO₂ <90% and increased time at SpO₂ >97%, without increasing time with TcPO₂ >10.7 kPa (80 mm Hg). Clinical trials targeting this higher SpO₂ range could be conducted without significant hyperoxic exposure.

NCT03360292.