SVC and Its Relationship to CVP Measurements in Liver Transplantation

Central venous pressure (CVP) measured invasively through a central venous catheter in the
internal jugular vein or through a right atrial port of a pulmonary artery catheter is
commonly used during liver transplant surgery. CVP measurements at the SVC-RA junction are a
function of circulating blood volume, right ventricle function, intrathoracic pressure. CVP
measurements can also be affected by the presence of tricuspid regurgitation. Because central
venous pressure measurements are determined by several factors and do not predict the
response to subsequent fluid bolus administration, they are considered "static measures" and
are poor indicators of fluid responsiveness.

Given the entirely intrathoracic location of the superior vena cava (SVC), its diameter and
collapsibility with positive pressure ventilation it is a potentially attractive method of
non-invasively estimating CVP.

SVC diameter and collapsibility index, dynamic measures of fluid responsiveness have been
successfully utilized as echocardiographic indices for fluid responsiveness in ventilated
septic patients. Whether SVC collapsibility is correlated with CVP measurements in liver
transplant patients is not known.

Consecutive patients undergoing liver transplant surgery will be included in the study.
Before surgical incision, during the preanhepatic phase, during the anhepatic phase, during
the postanhepatic phase and following closure of the deep fascial layer of the anterior
abdominal wall simultaneous measurement of SVC diameter, SBC collapsibility index and CVP
will be recorded.

Inclusion Criteria:

- 18 years of age

- undergoing liver transplantation surgery (cadaveric and living related)

Exclusion Criteria:

- Contraindication to Transesophageal echocardiography