[Effects of total intravenous anesthesia on evoked potentials during aneurysm clip placement surgery]

To explore the influences of total intravenous anesthesia (TIVA) on the feasibility and success rate of monitoring the evoked potentials (EP) and examine the correlations between EP changes and clinical outcomes in intracranial aneurysm surgery.

Thirty-one patients undergoing intracranial aneurysm surgery received TIVA. TIVA was maintained with a target controlled infusion (TCI) of propofol and a continuous infusion of remifentanyl. The bilateral SEP (somatosensory evoked potential) and MEP (motor evoked potentials) were monitored intra-operatively. And the changes of evoked potential and success rate were recorded. The preoperative and postoperative neurological outcomes and radiological manifestations were compared.

Bilateral SEP was detected in all cases. And the control side MEP was unsuccessfully monitored. Three patients had postoperative neurological deficits. The amplitudes of MEP and SEP declined simultaneously and failed to revert back to the baseline levels in 1 case. There was postoperative hemiplegia. And computed tomography showed multiple sites of ischemic brain infarction.

The administration of TIVA with propofol and remifentanyl enables successful SEP and MEP monitoring during intracranial aneurysm surgery. This protocol may detect early cerebral ischemia and reduce the incidence of ischemic stroke.