Cerebral oxygenation with different nasal continuous positive airway pressure levels in preterm infants

Objectives: This study evaluates the effect of varying nasal continuous positive airway pressure (NCPAP) level on cerebral blood flow (CBF) and oxygenation in preterm infants. Methods: Oxy-haemoglobin (HbO₂) and total haemoglobin (HbTot), as CBF estimates, and the ratio between HbO₂and HbTot (HbO₂/HbTot), as cerebral oxygenation estimate, were assessed by near-infrared spectroscopy in 26 stable preterm newborns at a postmenstrual age between 26 and 33 weeks. Baseline HbO₂, HbTot and HbO₂/HbTot values were initially collected with NCPAP at 5 cm H₂O and then compared with values obtained with NCPAP levels at both 3 and 8 cm H₂O. Results: Compared with 5 cm H₂O, cerebral HbO₂, HbTot and HbO₂/HbTot remained unchanged both after increasing (to 8 cm H₂O) and decreasing (to 3 cm H₂O) the NCPAP level. This result was observed both in regional areas (24 sites) and in the overall monitored area (frontal and parietal cortex). Compared with 8 cm H₂O, peripheral oxygen saturation significantly decreased at 3 cm H₂O (p=0.021). Heart rate did not change. Conclusions: No differences in CBF and cerebral oxygenation were observed with NCPAP levels in the range 3-8 cm H₂O despite a decrease in peripheral oxygenation with 3 cm H₂O.