1. Department of Anesthesiology, Urmia Imam Khomeini Hospital, Urmia University of Medical Science, Urmia, Iran
2. Department of Neurosurgery, Urmia Imam Khomeini Hospital, Urmia University of Medical Science, Urmia, Iran
3. Department of Anesthesiology, Mahabad Imam Khomeini Hospital, Urmia University of Medical Science, Mahabad, Iran