Continuous monitoring of blood oxygen saturation of internal jugular vein as a useful indicator for selective cerebral perfusion during aortic arch replacement.

We continuously monitored blood oxygen saturation in the internal jugular vein during selective cerebral perfusion for aortic arch operations and evaluated its efficacy as an indicator of cerebral oxygen metabolism. The selective cerebral perfusion method was applied in 11 patients who underwent operations for aortic arch replacement. Blood oxygen saturation in the internal jugular vein was continuously monitored at the bulbus jugularis with a fiberoptic catheter during the operation. Perfusion flow of 500 ml/min was continued for 134.7 +/- 14.9 minutes under moderate hypothermia at 25 degrees C, and bilateral temporal arterial pressure was 40 to 60 mm Hg. Blood gas data were used to estimate oxygen consumption, oxygen extraction ratio, and lactate uptake in the cerebrum. No patients had postoperative cerebral complications. Cerebral oxygen consumption was 2.93 +/- 0.4 ml/min/100 gm under general anesthesia at 36 degrees C. While selective cerebral perfusion at 25 degrees C decreased consumption to 0.92 +/- 0.39 ml/min/100 gm, it fell to about 30% of its former value. Blood oxygen tension in the internal jugular vein showed no significant correlation with rectal temperature. Selective cerebral perfusion did not significantly affect cerebral lactate uptake. In contrast, blood oxygen saturation in the internal jugular vein was significantly affected by temperature and cerebral flow during selective cerebral perfusion, and blood oxygen saturation in the internal jugular vein correlated closely with cerebral oxygen extraction ratio (r = 0.91). Cerebral oxygen metabolism was thus well maintained, and continuous monitoring of blood oxygen saturation in the internal jugular vein was found to serve as a useful indicator under selective cerebral perfusion during operations for aortic arch replacement.