Pre- and peri-operative factors associated with chronic critical illness in liver transplant recipients

Background: Chronic critical illness (CCI) is a new and increasing entity that accounts for substantial cost despite its low incidence. We hypothesized that patients with end-stage liver failure undergoing liver transplant would be at high risk for developing CCI. With limited liver donors it is essential to understand pre- and peritransplant predictors of CCI. Methods: To accomplish this we performed a retrospective cohort study at a large academic transplant center of all adult liver transplant patients from 2011 to 2017. We defined CCI as the need for mechanical ventilation for seven days or more post-transplant. Recipients who had re-transplantation during their index admission, acute rejection, or who died during transplant surgery were excluded. Logistic regression was performed using the Akaike information criterion (AIC) and the likelihood ratio test. Results: We identified 382 transplant recipients. Forty-five (11.8%) developed CCI. Univariable analysis identified 16 pre-transplant factors associated with post-transplant CCI. Subsequent multivariable logistic regression identified eight independent factors associated with CCI in liver transplant recipients including previous liver transplant, acute renal failure, frailty, lower albumin level, higher international normalized ratio, need for mechanical ventilation, and higher systolic pulmonary artery pressure. Pre-transplant factors associated with protection against CCI included higher Model for End-Stage Liver Disease (MELD) score. Conclusion: The incidence of CCI post-liver transplant is similar to the general population admitted to the intensive care unit. Pre-transplant factors associated with CCI can help identify at-risk patients, and furthermore, promote further research and interventions with the goal to decrease the incidence of CCI in the liver transplant recipients.