Non-Invasive Optical Quantification of Cerebral Tissue Oxygenation in Children with Single-Ventricle Congenital Heart...

To compare the accuracy of frequency-domain near-infrared spectroscopy (FD-NIRS) with clinically available optical measures of cerebral tissue oxygenation (StO₂) and arterial saturation (SaO₂).

We enrolled 24 children with single-ventricle congenital heart defects scheduled for cardiac catheterization. Intraoperative FD-NIRS and continuous-wave near-infrared spectroscopy (CW-NIRS) measurements of StO₂ were bilaterally obtained on the forehead. SaO₂ was simultaneously acquired with FD-NIRS and pulse oximetry. Noninvasive StO₂ and SaO₂ were compared with invasive superior vena cava (SVC) and descending aorta saturation measurements. These measurements were also used to compute cerebral tissue oxygen extraction fraction (OEF).

The FD-NIRS StO₂ was strongly correlated with invasive venous oxygen saturation (SvO₂) (R = 0.74, P < .001; bias, -2.8%). However, correlation between CW-NIRS StO₂ and invasive SvO₂ was weaker and not significant (R = 0.29, P = .34; bias, -2.5%). Invasive SaO₂ was correlated with FD-NIRS (R = 0.84, P < .001; bias, -3.2%) and pulse oximetry (R = 0.68, P = .001; bias, 0.2%) metrics of SaO₂, but pulse oximetry showed larger error at low saturations. Finally, FD-NIRS OEF and invasive OEF were strongly correlated (R = 0.61, P = .01; bias, 0.09).

Our study suggests that FD-NIRS provides more accurate quantification of StO₂ and SaO₂ than CW-NIRS and pulse oximetry in patients with single-ventricle heart defects. We also demonstrated and validated stand-alone OEF quantification using FD-NIRS.