Background and Aim Persistent pulmonary hypertension (PPHN) is a life-threatening condition treated with high oxygen concentrations in inspired air (fiO₂). Little is known about the course of cerebral oxygen saturation (r_cSO₂) and extraction (FTOE) in neonates with PPHN. Our aim is to explore the course of r_cSO₂ and FTOE in neonates with PPHN during the first 72 hours of life.

Methods In term neonates with PPHN r_cSO₂ was measured with near-infrared spectroscopy. Simultaneously, arterial oxygen saturation (SpO₂) was measured and FTOE was calculated:(SpO₂-r_cSO₂)/SpO₂. We obtained clinical factors such as pH, pCO₂, blood pressure, NO-therapy, sedatives and inotropics. We used Wilcoxon test and Spearman’s correlation to test significance.

Results We included six neonates (median GA 40+2wk, BW 3900g). R_cSO₂ increased from day 1 to day 2 (p=0.028) and FTOE decreased from day 1 to day 2 (p=0.027).

Clinical factors were not associated with r_cSO₂ and FTOE, but r_cSO₂ was nearly significantly positively associated with midazolam at day 2 (p=0.05), and negatively with pCO₂ at day 3 (p=0.051).

Conclusions Highest R_cSO₂-values and lowest FTOE-values were seen on day two, suggesting decreased oxygen consumption, possibly as a consequence of midazolam treatment. Even so, treatment with high fiO₂ did not lead to high levels of oxygen in brain tissue in most infants.