CEREBRAL OXIMETRY - A USEFUL MONITOR DURING CAROTID-ARTERY SURGERY

Cerebral oximetry was evaluated as a monitor of oxygenation during car otid endarterectomy in 22 patients. The oximeter was a reliable contin uous monitor, identifying changes in cerebral oxygenation during episo des of hypotension and after arterial occlusion. Changes in oxygenatio n correlated well with the surgical assessment of backbleeding after a rterial clamping, but less well with other methods which are used to m ake a decision on insertion of an arterial shunt. There was no correla tion between internal carotid artery stump pressure and change in cere bral oxygenation after application of the arterial cross clamp. Howeve r, cerebral oxygenation correlated weakly with the change in middle ce rebral artery velocity as measured by transcranial Doppler ultrasonogr aphy (r = 0.49, p < 0.02).