Rehabilitation and the post-intensive care syndrome across the recovery continuum: a narrative review.

Purpose

Improved survival from critical illness has produced a growing population of intensive care unit (ICU) survivors with new or worsened physical, cognitive, and mental-health impairment, defined as post-intensive care syndrome (PICS), and frequent distress among families/caregivers (PICS-family, PICS-F). This narrative review synthesises the evidence in adults treated in high-resource settings.

Methods

Rather than a formal guideline process, we used a structured descriptive approach: for each recommendation, we identified the predominant study design, assessed the consistency of findings, summarised uncertainties, and assigned an evidence-strength label (high, moderate, low, or insufficient).

Results

We summarise the definition of PICS and its overlap with related constructs (post-sepsis morbidity, chronic critical illness, post-COVID conditions, and frailty); the mechanisms linking acute injury to persistent disability, including skeletal-muscle pathobiology, neuroinflammation, mitochondrial and neuroendocrine dysfunction, and epigenetic change; and the instruments assessing the three PICS core domains (recommending a two-step assessment approach), as well as quality of life, across the care continuum. We describe preventive and rehabilitative interventions from the ICU (e.g., the ABCDEF bundle that includes light/no sedation, delirium prevention, early mobilisation and family participation) through the ward to the post-hospital phase, the heterogeneous organisation of post-ICU recovery services, PICS-F, the educational and cultural change needed, and the health-system and policy context. PICS-F affects 20-60% of relatives; nurse-led family interventions seem promising.

Conclusion

The evidence base remains limited and heterogeneous, preventing firm recommendations. Research priorities include harmonised outcome measurement, phenotyping of recovery trajectories, the optimal dose and timing of rehabilitation, and rigorous comparison of follow-up models.