Patients who are scheduled to receive living donor liver transplantation will be monitored with a radial and femoral arterial line. A pulmonary artery catheter will also be placed and central venous pressure, cardiac index, and cardiac output will also be monitored. Simultaneously, on the middle finger of the hand where the radial artery is monitored, Clearsight (Edwards Lifesciences, Irvine, CA), a finger cuff, is placed and noninvasive blood pressure, cardiac output, cardiac index are measured. Using the VitalDB program, the parameters measured with the invasive methods and the parameters obtained by the noninvasive method are compared.

In many end stage liver disease patients, cardiac output (CO) is increased and systemic vascular resistance (SVR) is decreased. During liver transplantation it is common to see hemodynamic instability due to massive blood loss and clamping of the major vessels. As a result invasive monitoring via a pulmonary catheter is usually done to continuously monitor the CO and SVR. However, because of its invasiveness, complications such as pulmonary artery rupture and ventricular arrhythmia can occur.

Clearsight (Edwards Lifesciences, Irvine, CA) is a noninvasive technique using a finger cuff to measure not only blood pressure but also CO and cardiac index (CI).

There have been previous reports on the correlation of this noninvasive method in other patient populations but no studies have been done in liver recipients. Also no studies have been done comparing SVR.

Patients presenting for living donor liver transplantation are anesthetized according to the SNUH protocol. Right radial and femoral arterial lines are placed. A central catheter is placed in the right jugular vein and a pulmonary artery catheter (Swan-Ganz CCOmbo CCO/SvO2™; Edward Lifesciences LLC, Irvine, CA, USA) is placed. This is connected to the Vigilance™ hemodynamic monitor (Edwards Lifesciences) and central venous pressure (CVP), CO, CI are monitored and SVR is calculated by the following equation: SVR=(Mean arterial pressure-CVP)*80/CO. The Clearsight system is connected after the finger cuff is placed on the middle finger of the right hand. Blood pressure, CO, CI are measured and SVR is calculated.

The variables are compared in the following phases:

Phase 1 (preanhepatic1): induction complete (baseline) Phase 2 (preanhepatic2): induction - recipient hepatectomy Phase 3 (anhepatic1): recipient hepatectomy - Inferior Vena Cava (IVC) clamping Phase 4 (anhepatic2): IVC clamping - reperfusion Phase 5 (neohepatic1 [reperfusion]) Reperfusion - 5 minutes postreperfusion Phase 6 (neohepatic2): 20 minutes after reperfusion Phase 7 (neohepatic3): 1 hour after reperfusion

The investigators hypothesize that the noninvasive hemodynamic monitoring method by the Clearsight will be able to replace the invasive monitoring by the pulmonary artery catheter.

Inclusion Criteria:

• routine living donor liver transplantation recipients needing pulmonary artery catheterization who have been informed and given consent

Exclusion Criteria:

• Patients with atrial fibrillation
• Contraindications to pulmonary artery catheterization or needing attention to insertion of pulmonary artery catheter: right-sided endocarditis, tumors, right sided valvular disease, left bundle branch block
• Patients with obstructive vascular disease in the upper extremities, anatomical deformities in the upper extremities, Raynaud syndrome, etc.