Reducing Pain With Methadone and Ketamine in Liver Transplant

The goal of this clinical trial is to learn if using methadone and ketamine during an adult deceased donor liver transplant can help decrease pain after surgery. The main questions it aims to answer are: * What impact does using methadone and ketamine during a deceased donor liver transplant have on pain after surgery? * Does the use of methadone and ketamine also have an impact on mental confusion (delirium) after surgery? Researchers will compare the use of methadone and ketamine to standard of care to see if the two drugs work to decrease pain and impact delirium after liver transplant. Participants will: * Receive either methadone and ketamine or standard of care during their deceased donor liver transplant. * Allow researchers to follow medical care throughout inpatient stay.