The progressive aging of the general population cause increase in number of extensive and long surgeries in older patients. Age is a risk factor for perioperative myocardial ischemia and Postoperative Cognitive Dysfunction (POCD) The suggested study will deal with the above-mentioned complication in patients older then 65 years undergoing major non-cardiac surgeries.

It has been shown that Isoflurane and sevoflurane may have a cardio-protective effect after cardiac surgery involving cardio-pulmonary bypass, and it was recommended that isoflurane should be used in these cases. A question was raised but haven't been answered yet, whether this cardio-protective effect exists also in non-cardiac major surgery.

The aim of this study is to evaluate whether there is a difference in the occurrence of postoperative cognitive dysfunction and perioperative myocardial ischemia between total intravenous anesthesia using propofol and isoflurane based anesthesia.

The progressive aging of the general population cause increase in number of extensive and long surgeries in older patients. Age is a risk factor for perioperative myocardial ischemia and Postoperative Cognitive Dysfunction (POCD) The suggested study will deal with the above-mentioned complication in patients older then 65 years undergoing major non-cardiac surgeries.

It has been shown that Isoflurane and sevoflurane may have a cardio-protective effect after cardiac surgery involving cardio-pulmonary bypass, and it was recommended that isoflurane should be used in these cases. A question was raised but haven't been answered yet, whether this cardio-protective effect exists also in non-cardiac major surgery.

The aim of this study is to evaluate whether there is a difference in the occurrence of postoperative cognitive dysfunction and perioperative myocardial ischemia between total intravenous anesthesia using propofol and isoflurane based anesthesia.

The suggested study is a randomized controlled study. 500 patients older then 65 years undergoing elective non-cardiac major surgeries will be studied.

On the day prior to surgery the patient will take a series computerized cognitive tests (Mindstream® cognitive health assessment, neurotrax®, Modiin, Israel). At the holding area before entering the operating room (OR) the patients will be randomly assigned to one of two study groups.

Group 1 -IA: anesthesia will be maintained using Isoflurane carried by O2/air. Group 2 - TIVA : anesthesia will be maintained with propofol. The patients will be followed for 3 months post-operatively. Cognitive function will be assessed 7 days and 3 months postoperatively using computerized tests and telephone interview.

Inclusion Criteria:

• Patients that refuse or unable to sign an informed consent

Exclusion Criteria:

• Patients with any unstable disease
• Patients treated with medication affecting the nervous system
• Patients with earring difficulty
• Patients that will not be able to participate in the study due to language barrier

500 patients older then 65 year, scheduled for elective non-cardiac, non-neuro surgery