Trajectories of cumulative fluid balance and the association with pressure injuries in ICU patients

This study aimed to investigate the longitudinal trajectories of cumulative fluid balance (CFB) in intensive care unit (ICU) patients and analyze the relationship between different trajectory groups and the occurrence of pressure injuries (PIs). In this retrospective longitudinal study, we obtained health-related data from the Medical Information Mart for Intensive Care IV database, including sociodemographic, disease-related variables, and ICU treatment variables. The daily CFB adjusted for body weight was calculated, and the occurrence of PIs during the ICU stay was recorded. A group-based trajectory model was used to explore the different CFB trajectories. Binary logistic regression was used to analyze the relationship between the CFB trajectory group and PIs. Among the 4,294 included participants, we identified four distinct trajectories of CFB in ICU patients: the rapid accumulation group (12.5%), the slow accumulation group (28.5%), the neutral balance group (41.7%), and the negative decrease group (17.3%). After adjusting for some sociodemographic, disease-related variables, and ICU treatment variables, the rapid accumulation group had an OR of 1.63 (95 % CI : 1.30, 2.04) for all stages of PIs and an OR of 1.36 (95 % CI : 1.08, 1.72) for stage II or higher PIs compared to the neutral balance group. Four unique trajectories of CFB were identified among patients in the ICU, including rapid accumulation, slow accumulation, neutral balance, and negative decrease. Rapid accumulation independently increased the risk of PIs during ICU stay. What is known? • Fluid balance in ICU patients fluctuates continuously, and fluid overload is associated with various adverse clinical outcomes. • A potential association between fluid balance and pressure injuries may exist, but evidence on the relationship between longitudinal changes in fluid balance and the development of pressure injuries remains limited. What is new? • Four distinct trajectories of cumulative fluid balance (CFB) were identified in ICU patients, including rapid accumulation, slow accumulation, neutral balance, and negative decrease. • Rapid fluid accumulation was an independent risk factor for the development of pressure injuries in the ICU. • The findings highlight the potential value of integrating dynamic CFB monitoring into pressure injury prevention strategies in critical care settings.