Temporal Dynamics and Transitions in Limitation of Life-Sustaining Treatment Across ICU Stay: A Multicenter Cohort Study

Objective: To analyze the temporal dynamics and transitions in Limitation of Life-Sustaining Treatment (LLST) classifications between ICU admission and outcome, describe associated patient profiles, and identify factors influencing these transitions in a multicenter cohort.Method: This retrospective cohort study included 13,215 adult patients admitted to ICUs across five hospitals in Curitiba, Brazil, from May 1, 2023, to December 31, 2024. Patients were daily classified into one of four LLST levels. We compared admission characteristics, severity scores (APACHE II, SOFA, Clinical Frailty Scale [CFS]), clinical course, and outcomes among groups with unchanged LLST, progression to less restrictive LLST, and progression to more restrictive LLST. Ordinal logistic regression assessed the impact of ICU admission characteristics on LLST levels at outcome, while longitudinal models evaluated daily LLST variation.Results: This multicenter retrospective study analyzed 13,215 ICU patients (2023-2024) to evaluate LLST transitions. Most patients (89.4%) maintained their initial LLST classification, while 9.8% progressed to more restrictive levels and 0.8% to less restrictive. Patients progressing to stricter LLST were older (74±14 vs. 65±17 years), had higher severity scores (APACHE II 23 vs. 11; SOFA 7 vs. 3), greater frailty (CFS 5 vs. 3), and worse outcomes (75% mortality vs. 5.8%). Key predictors included age (OR=2.3), frailty (OR=1.42 per CFS unit), and admission SOFA (OR=1.27 per unit). Half of initial LLST decisions occurred within 4 days, with escalating organ dysfunction (rising ΔSOFA) in restrictive cases. The findings underscore how patient acuity and early decisions shape LLST trajectories, highlighting opportunities to optimize end-of-life care through proactive assessment.Conclusion: LLST decisions are dynamic during ICU stays and are significantly influenced by patient age, frailty, initial severity, and admission type. A substantial proportion of patients experience progression to more restrictive LLST, which is associated with higher morbidity and mortality. Early identification of at-risk patients and proactive discussions about care goals are crucial to optimize resource allocation and improving end-of-life care quality in intensive care.