Hypoperfusion during manipulation of the heart in off-pump coronary artery bypass (OPCAB) surgery may lead to postoperative neurological complications. Therefore, it will be necessary to monitor cerebral function during OPCAB surgery. In this study, we compared regional cerebral oxygenation (rSO₂) by near-infrared spectroscopy (NIRS) with jugular bulb venous oxygen saturation (SjvO₂) and assessed whether rSO₂ measured by NIRS could be an alternative method of SjvO₂ during OPCAB surgery.

A total of 20 patients who underwent OPCAB surgery were studied. A fiberoptic catheter was placed in the right jugular bulb to measure SjvO₂ while a cerebral oximeter based on NIRS, INVOS 5100B was used to monitor rSO₂. Radial arterial and jugular bulb blood samples were drawn simultaneously from baseline every hour during operation. The values of rSO₂ were compared with SjvO₂ values.

For all data points (n = 78) for all patients combined, rSO₂ values were significantly correlated with SjvO₂ values (r = 0.513, P < 0.0001). There were significant correlations between arterial carbon dioxide and values of SjvO₂ (r = 0.393, P = 0.0002) and rSO₂ (r = 0.432, P < 0.0001).

We concluded that NIRS correlates with SjvO₂ in this patient population. These findings suggest that near-infrared spectroscopy may be useful in assessing cerebral oxygenation during OPCAB surgery.