Effects of Increased Tidal Volume on Internal Jugular Vein Cross-sectional Area

Effects of Increased Tidal Volume on Internal Jugular Vein Cross-sectional Area

As increasing tidal volume, the cross sectional area and circumference of Internal Jugular Vein (IJV) could increase. And In the previous study, Trendelenburg position can increase size of IJV. So investigators would compare the cross sectional area, circumference of IJV and peak airway pressure in neutral and Trendelenburg position

Inclusion Criteria:

• patients who are undergoing general anesthesia

Exclusion Criteria:

• history of IJV cannulation
• uncontrolled cardiovascular disease
• severe pulmonary problem
• cervical spinal impairment