Cross-Sectional area and intravascular pressure of the right internal jugular vein during anesthesia: Effects of Trendelenburg position, positive intrathoracic pressure, and hepatic compression

Study Objective: To determine changes in the cross-sectional area of the right internal jugular vein (RIJV) in response to positive intrathoracic pressure and hepatic compression in mechanically ventilated patients during general anesthesia. Design: Prospective, nonrandomized study. Setting: A university medical center. Patients: 15 ASA physical status II and III adult patients undergoing RIJV cannulation after anesthetic induction and endotracheal intubation. Interventions: Patients were studied first supine and then at a 10 degrees and 20 degrees Trendelenburg tilt. The cross-sectional area of the RIJV was determined by two-dimensional ultrasound before and during 1) an end-inspiratory hold of 20 cm H2O; 2) hepatic compression for 10 seconds; and 3) both maneuvers applied simultaneously. Subsequently, the RIJV was cannulated and thp intravascular pressure was measured during the same sequence of maneuvers. Measurements and Main Results: In supine patients, the cross-sectional area of the RIJV significantly increased during the end-inspiratory hold, during hepatic compression, and with both maneuvers performed simultaneously (p < 0.05). With a 10 degrees Trendelenburg tilt, only both maneuvers applied simultaneously increased the cross-sectional area of the RIJV significantly, and with the 20 degrees Trendelenburg tilt, no further increase was seen.