The investigators are trying to evaluate the agreement of cardiac output measurements taken using the specific thermistor-tipped arterial catheter ( the VolumeView ™ catheter) and the EV1000 ™ monitoring platform ( Edward lifesciences, Irvine, CA, USA) with measurements taken using continuous pulmonary artery thermodilution cardiac output monitoring during orthotopic liver transplantation.

In cirrhotic patient undergoing liver transplantation, there are an altered patterm of circulation, which is characterized by increased cardiac output, decreased peripheral vascular resistance, and reduced ventricular response to physiological, pharmacological, and surgical stress. Large blood loss and clamping/declamping of the inferior vena cava and portal vein during liver transplantation surgery can affect intravascular volume status, which in turn can lead to hemodynamic instability. Therefore, reliable cardiac output monitoring is particularly useful in the cirrhotic patient undergoing liver transplant. Pulmonary artery thermodilution has been used as a standard method for cardiac output assessment for many years. Pulmonary artery catheter can cause rare but serious complications. And it has some limitations for continuously monitoring cardiac output during rapid hemodynamic changes.

Recently, several minimally invasive CO monitors have been developed. The pulse contour technique continuously estimates CO through mathematical analysis of the waveform of arterial pressure. However, previous studies evaluating the reliability of the pulse contour techniques indicated conflicting results in cirrhotic patients during liver transplantation. Most of studies were performed by analyzing from radial artery pressure waveform. Because of rapid changing of intravascular volume, using inotropics, the monitoring of femoral artery pressure has been recommended during liver transplantation.

A new pulse wave analysis system has developed and introduced into clinical practice that consists of a specific thermistor -tipped femoral arterial catheter ( the VolumeView™ catheter) and the EV1000™ monitoring platform ( Edward lifesciences, Irvine, CA, USA). To continuously assess CO based on the femoral arterial pressure curve signal and it uses transpulmonary thermodilution for calibration. We are trying to evaluate the agreement of cardiac output measurements taken using EV1000™ / VolumeView™ with measurements taken using continuous pulmonary artery thermodilution cardiac output monitoring during orthotopic liver transplantation.

Inclusion Criteria:

subjects undergoing living donor liver transplantation during the study period subjects older than 20yrs who can give informed consent

Exclusion Criteria:

those who are confirmed moderate severe aortic regurgitation by echocardiography those with infection on cannulation site

patients who are performed liver transplantation in Samsung medical center