Abnormalities of liver function during critical illness

Purpose of review Liver dysfunction is a frequent yet underrecognized feature of critical illness, affecting up to 20–40% of ICU patients. Even mild abnormalities in liver function tests are associated with increased morbidity, prolonged ICU stay, and higher mortality. Hepatic dysfunction may be the primary reason for ICU admission or develop during the ICU stay. Its clinical presentation is broad, ranging from abnormal liver function tests due to sepsis, drug toxicity, or hypoxia during critical illness, to acute liver failure in previously healthy individuals, and acute-on-chronic liver failure in patients with preexisting liver disease. Recent findings Recent advances highlight the importance of dynamic liver function testing, such as indocyanine green clearance, in early detection and prognostication. Moreover, evolving concepts around acute-on-chronic liver failure (ACLF) emphasize its systemic nature and the need for timely intervention, including liver support therapies and transplantation. Understanding the interplay between hepatic dysfunction and multiorgan failure is essential for improving outcomes in this vulnerable population. Summary This review highlights recent advances in understanding into the mechanisms, diagnosis, and management of liver dysfunction in critically ill patients, with a particular emphasis on ACLF.