The Effect of Trendelenburg Position on CCA Blood Flow

Influence of Anesthesia, Pneumoperitoneum, and Patient Position on Common Carotid Artery Blood Flow During Laparoscopic Gynecology Operation

The investigators will evaluate the change of the common carotid artery blood flow according to patient's position and penumoperitoneum.

The study will include 20 patients undergoing gynecological surgery. The common carotid artery blood flow will be measured using Doppler US during the following conditions; supine position before induction of anesthesia, supine position immediately after induction of anesthesia, supine position with penumoperitoneum, head-down position with or without pneumoperitoneum.

Inclusion Criteria:

• ASA class I,II
• patients undergoing gynecology surgery under trendelenburg position
• Age ranges from 20 to 70

Exclusion Criteria:

• BMI > 32
• Pregnancy
• Patients who did not agree to study
• Patients with allergies to the drugs used in this study
• Patients with anatomical variations or lesions in cervical or cranial vascular portion
• Patients with arrhythmia that may alter patient's cardiac output(e.g. artrial fibrillation)