Persistent Inflammation, Immunosuppression, and Catabolism: Evolution of Multiple Organ Dysfunction.

BACKGROUND Multiple organ dysfunction (MOD) has plagued intensive care units (ICUs) for more than four decades, and its epidemiology has evolved because more patients are surviving previously lethal insults. Over the years, different predominant phenotypes of MOD have been described, all of which have consumed tremendous healthcare resources and have been associated with prolonged ICU stays and prohibitive mortality rates. METHODS Review of the English-language literature. RESULTS By the 1990s, it became widely accepted that MOD could ensue after both infectious and non-infectious insults by what appeared to be a similar auto-destructive systemic inflammatory response. A 1996 analysis recognized that MOD was a bimodal phenomenon. As a result of years of implementation efforts, fewer patients died of early fulminant sepsis, and those who developed MOD survived hospitalization. Unfortunately, a substantial portion of these patients enter a state of persistent inflammation, immunosuppression, and catabolism (PICS) marked by persistent loss of lean body mass with failure to rehabilitate, sepsis recidivism necessitating re-hospitalization, increasing functional dependence, and an indolent path to death. CONCLUSION Unfortunately, as our population ages and peri-operative care improves, PICS will become an insurmountable epidemic. We believe PICS is the next horizon in surgical critical care and have developed a program to study the pathogenesis and novel therapies for this vexing problem.