A Physiologic State Severity Classification (PSSC) derived from clustering of 17 cardiorespiratory variables was used to predict cytokine response in critically ill posttrauma patients. The PSSC defined physiologic states: A-State (A), normal stress response; B-State (B), metabolic insufficiency; C2-State (C), respiratory insufficiency. Bayesian analysis of these states defined a probability of death (Pdeath). 416 studies from 60 newly studied multiple trauma patients (70% males, Injury Severity Score = 27.5) were analyzed; 45 (75%) had sepsis (s), 28 (47%) had sepsis-adult respiratory distress syndrome (s-ARDS). Of 35 survivors (66% s, 37% s-ARDS, mean Pdeath = .42) 23% were predominantly A, 66% B, and 11% C. Of 25 deaths (88% s, 60% s-ARDS, mean Pdeath = .64) 0% were A, 44% B, and 56% C. PSSC States were correlated with incidence and mean plasma levels (pl) in picograms/mL of cytokines. 23 samples from recovering nonseptic trauma patients were used as controls.