Background:  We compared two different near‐infrared spectrophotometers: cerebral tissue oxygenation index (TOI) measured by NIRO 200 and regional cerebral oxygenation index (rSO₂) measured by INVOS 5100 with venous oxygen saturation in the jugular bulb (SjO₂) and central SvO₂ from the superior caval vein (SVC) during elective cardiac catheterization in children.

Methods:  A prospective observational clinical study in 31 children with congenital heart defects in a catheterization laboratory was undertaken. TOI was compared with SjO₂ in the left jugular bulb and with SvO₂. rSO₂ was compared with SjO₂ from the right jugular bulb and SvO₂. Linear regression analysis and Pearson’s correlation coefficient were calculated and Bland–Altman analyses were performed.

Results:  Cerebral TOI and SjO₂ were significantly correlated (r = 0.56, P < 0.0001), as well as TOI and SvO₂ with r = 0.74 (P < 0.0001). Bland–Altman plots showed a mean bias of −4.3% with limits of agreement of 15.7% and −24.3% for TOI and SjO₂ and a mean bias of −4.9% with limits of agreement of 10.3% and −20.1% for TOI and SvO₂. Cerebral rSO₂ and SjO₂ showed a significant correlation (r = 0.83, P < 0.0001) and rSO₂ and SvO₂ showed excellent correlation with r = 0.93 (P < 0.0001). Bland–Altman plots showed a mean bias of −5.2% with limits of agreement of between 8.4% and −18.8% for rSO₂ and SjO₂ and a mean bias of 5.6% with limits of agreement of 13.4% and −2.2% for rSO₂ and SvO₂.

Conclusions:  Both near‐infrared spectroscopy devices demonstrate a significant correlation with SjO₂ and SvO₂ values; nevertheless both devices demonstrate a substantial bias of the measurements to both SjO₂ and SvO₂.