Comorbidities, Routine Biomarkers and Early Septic Shock Occurrence in Patients with Sepsis: A Retrospective Longitudinal Study.

Background/Objectives: Early recognition of septic shock among patients with sepsis remains clinically important, particularly in settings where risk stratification relies on routinely available indicators. This study aimed to identify patient-related factors associated with septic shock, with particular emphasis on comorbidities, and to examine early changes in selected inflammatory markers during the first 72 h after diagnosis. Methods: This study included 106 intensive care patients diagnosed with sepsis or septic shock according to Sepsis-3 criteria. Baseline demographic, clinical, and laboratory characteristics were compared between groups using univariate tests. Candidate predictors were then evaluated using a LASSO-assisted logistic regression model. Longitudinal changes in inflammatory markers were analyzed using linear mixed-effects models. Results: Among baseline inflammatory markers, only procalcitonin was significantly higher in patients with septic shock than in those with sepsis. In the final logistic regression model, higher procalcitonin levels were associated with greater odds of septic shock, whereas gastrointestinal comorbidity was associated with lower odds. Patients older than 75 years also had significantly higher odds of septic shock. The model showed satisfactory discrimination (AUC = 0.795). During the first 72 h, only neutrophil percentage demonstrated a significantly different temporal pattern between groups. Conclusions: Early recognition of septic shock may benefit from combining routine biomarkers with patient-related clinical characteristics rather than relying on isolated laboratory measurements alone. Procalcitonin, older age, gastrointestinal comorbidity, and early neutrophil dynamics emerged as the most informative signals, although these findings require validation in larger multicenter cohorts.