Hepatic drug metabolism is altered in critically ill patients. The eti
ology and mechanisms of the alterations are not clearly understood and
are difficult to address in clinical studies. For this reason, in vit
ro and animal models were developed to investigate the effects of crit
ical illness on hepatic drug metabolism. Specifically, those with seps
is, septic shock, hemorrhagic shock, trauma, neurotrauma, and burns ar
e populations that have been studied. Most of this research, however,
has not led to established guidelines for the administration of drugs
in these populations.