Critical Episodes of Inflammation, Catabolism, and Immunosuppression Define Mortality Risk in Chronic Critical Illness

Background/Objectives: A globally recognized definition of chronic critical illness (CCI) is lacking. Temporal criteria produce variable estimates, while pathophysiological models emphasize inflammation, catabolism, and immunosuppression (ICS). The relationship between ICS dynamics and mortality remains unclear.

Methods

This retrospective single-center cohort study analyzed real-world data from 3374 adult intensive care unit (ICU) patients. CCI was defined by first detection of the ICS triad: C-reactive protein (CRP) >20 mg/L, albumin <30 g/L, and absolute lymphocyte count <0.8 × 109/L within 24 h. CCI days were classified as critical or non-critical. Mortality and mortality density were compared across CCI groups and periods.