Cold ischemia time is an important risk factor for post-liver transplant prolonged length of stay.

Risk analysis of cold ischemia time (CIT) in liver transplantation has largely focused on patient and graft survival. Posttransplant length of stay is a sensitive marker of morbidity and cost. We hypothesize that CIT is a risk factor for posttransplant prolonged length of stay (PLOS) and aim to conduct an hour-by-hour analysis of CIT and PLOS. We retrospectively reviewed all adult, first-time liver transplants between March 2002 and September 2016 in the United Network for Organ Sharing database. The 67,426 recipients were categorized by hourly CIT increments. Multivariate logistic regression of PLOS (defined as >30 days), CIT groups, and an extensive list of confounding variables was performed. Linear regression between length of stay and CIT as continuous variables was also performed. CIT 1-6 hours was protective against PLOS, whereas CIT >7 hours was associated with increased odds for PLOS. The lowest odds for PLOS were observed with 1-2 hours (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.45-0.92) and 2-3 hours (OR, 0.65; 95% CI, 0.55-0.78) of CIT. OR for PLOS steadily increased with increasing CIT, reaching the greatest odds for PLOS with 13-14 hours (OR, 2.05; 95% CI, 1.57-2.67) and 15-16 hours (OR, 2.06; 95% CI, 1.27-3.33) of CIT. Linear regression revealed a positive correlation between length of stay and CIT with a correlation coefficient of +0.35 (P < 0.001). In conclusion, post-liver transplant length of stay is sensitive to CIT, with a substantial increase in the odds of PLOS observed with nearly every additional hour of cold ischemia. We conclude that CIT should be minimized to protect against the morbidity and cost associated with posttransplant PLOS. Liver Transplantation 24 762-768 2018 AASLD.