Trajectory and determinants of intensive care unit–acquired weakness in critical illness: A multicentre, prospective, longitudinal study

Abstract Background Intensive care unit–acquired weakness (ICU‐AW) is prevalent and adversely affects patient outcomes. Muscle strength progression and response to rehabilitation differ across ICU populations. However, the trajectories, determinants and prognoses of muscle strength changes remain unclear. Aim This study aimed to investigate the trajectory and determinants of ICU‐AW in critical illness and its impact on 60‐day postadmission mortality. Study design A multicentre prospective cohort study was conducted, involving critically ill patients from 10 ICUs across five tertiary hospitals in Fujian Province, China. Patients were evaluated using the Medical Research Council (MRC) scale at three time points: within 48 h of ICU admission or within 24 h of regaining consciousness (T1), within 24 h of ICU discharge (T2) and at the time of hospital discharge (T3). The latent class growth mixed model was utilized for data analysis, and multivariable logistic regression was employed to examine the determinants of muscle strength trajectories. Results This study encompassed 343 patients from five tertiary hospitals. Three latent trajectory groups were identified: a low‐level decline group (5.83%), a medium‐level stability group (25.36%) and a high‐level recovery group (68.81%). Multivariable logistic regression revealed that Charlson comorbidity index (CCI) and alcohol consumption significantly influenced the trajectory of muscle strength development in ICU patients ( p < .05). The mortality rate at 60 days was significantly higher in both the low‐level decline and medium‐level stability groups compared with the high‐level recovery groups ( p < .05). Conclusions This study identified three muscle strength trajectories in ICU patients: low‐level decline, medium‐level stability and high‐level recovery. CCI and alcohol consumption significantly influenced these trajectories. The lower 60‐day mortality rate in the high‐level recovery group underscores the need for early intervention and tailored care. Relevance to Clinical Practice Developing targeted rehabilitation strategies for those at risk of low‐level decline or medium‐level stability group is challenging and may potentially improve recovery and outcomes.