Effects of Sevoflurane and Propofol on Optic Nerve Sheath Diameter During Laparoscopic Gynecologic Surgery

Randomized,Double-Blind Trial A Comparative Analysis of the Effects of Sevoflurane and Propofol on Optic Nerve Sheath Diameter During Steep Trendelenburg Position and Pneumoperitoneum for Laparoscopic Gynecologic Surgery

Intracranial pressure（ICP) increases during laparoscopic gynecologic surgery increase (ICP) and may alter optic nerve sheath diameter(ONSD).This study measures ONSD in different team because sevoflurane and propofol have different effects on ICP.Half of participants will receive sevoflurane anesthesia,while the other half undergo propofol anesthesia.

Due to the anatomical and physiological characteristics of optic nerve sheath ,ONSD increases when ICP rises.

Sevoflurane and propofol have different effects on ICP.When sevoflurane concentration >1.1 minimum alveolar concentration（MAC),ICP increases because of cerebral vasodilatation；on the other hand ,propofol constricts the blood vessels and ICP decreases.

ICP increases during laparoscopic gynecologic surgery because of steep Trendelenburg position and pneumoperitoneum .

Meanwhile,sevoflurane affects self regulation of cerebral blood flow on the way of dose dependent,but propofol has no effects on self regulation of cerebral blood flow.

Inclusion Criteria:

• American Society of Anesthesiologists physical status diagnosed as I or II

Exclusion Criteria:

• neuromuscular diseases;laboratory abnormalities in electrolytes; liver and kidney dysfunction;allergy to general anesthetics;pregnancy;ocular lesions including ocular trauma, optic neuritis, optic nerve tumor.