M ultiple organ failure (MOF) emerged as a deadly syndrome in surgical intensive care units (ICUs) in the early 1970s. Sepsis and trauma were the primary inciting events. With tremendous the advances in care over the ensuing four decades, the epidemiology of MOF evolved from a fulminant phenotype of progressive organ failure leading to early death into a lingering phenotype of chronic critical illness (CCI) leading to indolent death. 1,2 CCI was first described in a 1985 article entitled "to save or let die." 3 This was followed by reports in the 1990s describing CCI in ventilator-dependent patients who were discharged to long-term acute care (LTAC) facilities for ventilator weaning. 4 These reports focused on long-term functional disability using descriptive terms including "polyneuropathy of critical illness," "myopathy of critical illness," and "ICU-acquired weakness." 5 It was subsequently recognized that CCI affected other systems. 6 Most recently, the CCI literature has popularized the term "postintensive care unit syndrome," adding that ICU delirium contributes to long-term cognitive impairments with depression and posttraumatic stress disorders. 7 These reports have largely come from heterogeneous medical ICU patients and implicate different risk factors depending upon the patient population, but offer no unifying underlying pathobiology for CCI.In a 2012 review article, the University of Florida Sepsis Critical Illness Research Center coined the term persistent inflammation, immunosuppression, and catabolism syndrome (PICS) to describe underlying pathobiology of the CCI phenotype that is now commonly seen in surgical ICU survivors. 8 This term was proposed to provide a mechanistic paradigm in which to study CCI in surgical ICU patients who are now surviving previously lethal inflammatory insults (e.g., trauma, sepsis, burns, and pancreatitis). The purpose of this review article is to summarize the shift from MOF into PICS-CCI in surgical patients.