Neuromonitoring During Rapid Ventricular Pacing in Patients Undergoing Cerebral Aneurysm Surgery

To evaluate the effect of rapid ventricular pacing on the oxygenation of the brain in patients scheduled for cerebral aneurysm clipping surgery or arteriovenous malformation surgery.

Patients scheduled for cerebral aneurysm clipping surgery or arteriovenous malformation surgery(ASA 1to 3 over 18years) receive standard care general anesthesia including central venous line for rapid ventricular pacing technique. A contralateral Foresight sensor is placed on the forehead of the patient at induction. After the craniotomy two micro electrodes(PBtO2 and cerebral blood flow) are placed in the brain and fixated. A subdural strip electrode is placed on the surface of the brain to record the electrical activity. Effect of mild hyperventilation and oxygenation with 100% O2 is evaluated.

Oxygenation of the brain is measured by near-infrared spectroscopy and by evaluation of the brain tissue oxygen pressure by two microelectrodes placed in the brain.

Effect of ventilation with 100% oxygen on cerebral blood flow and cerebral tissue oxygenation measured by thermal diffusion flowmetry and brain tissue oxygen pressure measured by microelectrodes placed in the brain in combination with near-infrared spectroscopy, respectively.

Intraoperative ( Start of ventilation at 100% oxygen until bloodgas analyses shows an increase in arterial oxygen pressure.)

Effect of hyperventilation (defined as arterial carbon dioxide pressure between 24 and 32 millimeter mercury) on cerebral blood flow and cerebral tissue oxygenation measured by thermal diffusion flowmetry and brain tissue oxygen pressure measured by microelectrodes placed in the brain in combination with near-infrared spectroscopy, respectively.

Intraoperative (Start of hyperventilation until bloodgas analyses shows an arterial carbon dioxide pressure between 24 and 32 millimetre of mercury.)

Inclusion Criteria: scheduled for cerebral aneurysm surgery or arterial venous malformation American Society of Anesthesiologists classification 1, 2, or 3 Exclusion Criteria: non

Saldien V, Menovsky T, Rommens M, Van der Steen G, Van Loock K, Vermeersch G, Mott C, Bosmans J, De Ridder D, Maas AI. Rapid ventricular pacing for flow arrest during cerebrovascular surgery: revival of an old concept. Neurosurgery. 2012 Jun;70(2 Suppl Operative):270-5. doi: 10.1227/NEU.0b013e318236d84a.