Post-Intensive Care Syndrome patients experience long-term deficits in cognitive and physical function

More than half of ICU survivors may experience Post-Intensive Care Syndrome (PICS), which involves new or worsening physical, psychological, or cognitive impairments after a critical illness. Now a new study published at the ATS 2025 International Conference finds that these patients experience long-term deficits in cognitive function and ability to perform daily activities.

Researchers also identified key risk factors for PICS. The findings could be used to help identify patients at elevated risk of PICS so they can receive more appropriate care. The study could also potentially lead to the development of more targeted interventions to improve patient recovery.

Importantly, our results show that there are differences in the trajectories of each of these functional impairments, which gives us a more detailed and nuanced understanding of the unique challenges that patients with PICS experience following their critical illness."

Justin Banerdt, MD, MPH, a pulmonary and critical care fellow in the division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University Medical Center

The study builds on the team's prior research showing that delirium is an independent predictor of long-term cognitive impairment and worse functional outcomes following critical illness. Despite growing recognition of the significant morbidity associated with PICS, little has been known about the trajectory of these impairments, or about the factors that increase patients' risk.

For the new study, researchers conducted a retrospective analysis on 804 ICU survivors. They identified two recovery trajectories, one of which was consistent with PICS. Patients with the PICS trajectory had persistently worse cognitive function, as well as progressively more dependence on activities of daily living (ADLs) and instrumental activities of daily living (IADLs) through the first year of recovery.

"It is striking that not only did this group of patients with PICS show no evidence of recovery in performing ADLs and IADLs, but their functional deficits in these areas actually continued to worsen even up to a year after their critical illness," he said.

Risk factors included older age, worse baseline cognition, and greater baseline frailty. The latter was strongly associated with development of PICS, suggesting that pre-illness frailty is an important predictor of recovery from critical illness, Dr. Banerdt said.

Surprisingly, clinical variables like severity of illness and delirium duration were not significantly associated with PICS trajectory, he noted.

The findings also give clinicians a better understanding of how different areas of function change over time for these patients, which could lead to more targeted interventions like cognitive, physical, and occupational therapy, Dr. Banerdt added.

Future research projects will investigate possible pathophysiologic mechanisms underlying PICS and assess whether targeted interventions improve recovery trajectories. The team also plans to develop and validate a clinical prediction tool for PICS.