This is a single center prospective observational study to compare QStat parameter measurements in arterial and venous blood samples collected in parallel from patients undergoing liver transplantation.

In this single center prospective observational study, 25 cardiac surgery subjects will enrolled, each with parallel artrial and venous samples collected at 3 time points to yield 75 matched samples for analysis on the Quantra System with the QStat Cartridge.

Inclusion Criteria:

• Subject is >=18 years
• Subject is scheduled for liver transplant surgery
• Subject or subject's legally authorized representative (LAR) is willing to provide informed consent

Exclusion Criteria:

• Subject is younger than 18 years of age
• Subject is pregnant
• Subject is incarcerated at the time of the study
• Subject is affected by a condition that, in the opinion of the treatment team, may pose additional risks
• Subject, or subject's LAR, is unable or unwilling to provide informed consent

Adult patients undergoing liver transplant surgery.