Effects of incrementally increasing tidal volume on the cross-sectional area of the right internal jugular vein.
BACKGROUND
Different tidal volume (TV) settings during mechanical ventilation alter intrathoracic blood volume, and these changes could alter central venous pressure and the cross sectional area (CSA) of the right internal jugular vein (RIJV). The aim of this study was to determine the optimal TV for maximizing the CSA of the RIJV in the supine and Trendelenburg positions in anesthetized patients.


METHODS
Forty patients were randomly allocated to a supine group (Group S, n = 20) or a Trendelenburg group (Group T, n = 20) by computer generated randomization. RIJV CSAs were measured repeatedly after increasing the inspiratory volume in 1 ml/kg increments from a TV of 8 ml/kg to 14 ml/kg using ultrasound images.


RESULTS
Peak inspiratory pressure increased significantly on increasing TV from 11 ml/kg to 14 ml/kg and between baseline (TV 8 ml/kg) and 11 ml/kg in both groups (P < 0.05). RIJV CSA was not increased versus baseline even after TV changes in either group and no intergroup difference was found.


CONCLUSIONS
TV increases do not increase the CSA of the RIJV within the TV range 8 to 14 ml/kg in the supine or 10° Trendelenburg position.
Department of Anesthesiology and Pain Medicine, Gachon University, Gil Medical Center, Incheon, Korea.
Youn Yi
YY
Jo
Hong Soon
HS
Kim
Mi Geum
MG
Lee
Dong Young
DY
Kim
Hae Keum
HK
Kil
Cross sectional area; Internal jugular vein; Tidal volume; Trendelenburg position