Helping ICU patients regain independence: How early rehabilitation can speed recovery

A multicenter study across Japan found that ICU patients receiving more intensive rehabilitation regained independence faster after critical illness. Among 121 patients on mechanical ventilation, higher rehabilitation dose and mobility levels were linked to a lower risk of delayed recovery. The findings highlight that purposeful, early mobilization can improve outcomes and shorten recovery for ICU survivors.

When patients survive critical illness and leave the intensive care unit (ICU), many still face a long road to recovery. One of the most important milestones is regaining independence in activities of daily living (ADL) like the ability to walk, dress, bathe, and manage basic self-care without assistance. Unfortunately, many ICU survivors, especially those who required mechanical ventilation, struggle with muscle weakness, fatigue, and reduced physical function for weeks or even months.

This multicenter study across eight hospitals, led by study Professor Shinichi Watanabe from Nagoya Medical Center in Japan, examined whether the amount and intensity of rehabilitation therapy provided in the ICU influence how quickly patients regain their independence. This study was published on and made available in the Journal of Intensive Medicine on 14 October 2025. Professor Watanabe explained, “We hypothesized that higher rehabilitation dose and intensity would be associated with faster and more complete functional recovery.”

Researchers analyzed data from 121 adult ICU patients who had been on mechanical ventilation for at least 48 hours. Patients who were already dependent in walking before admission or had severe neurological or terminal illnesses were excluded. All participants received rehabilitation during their ICU stay, including exercises tailored to their condition, such as assisted range-of-motion, sitting up in bed, standing, and walking practice.

The team focused on five key rehabilitation parameters during the ICU stay: dose, measured using the Mobilization Quantification Score (MQS), which combines duration and difficulty of each activity; intensity, measured by the highest level achieved on the ICU Mobility Scale (IMS), from lying in bed to walking independently; duration, representing total active exercise time; frequency, or number of rehabilitation sessions; and start time, defined as days from ICU admission to first mobilization. Patients’ ADL function was measured using the Barthel Index (BI) before ICU admission, at ICU discharge, and during follow-up. Based on recovery patterns, patients were categorized as early recovery, i.e.  those who regained independence (BI ≥ 85) within 14 days after ICU discharge; recovery i.e. those who regained independence by hospital discharge; and delayed recovery, i.e. those who remained dependent at hospital discharge.

Two factors: rehabilitation dose and mobility intensity, were strongly linked to avoiding delayed recovery. Patients in the delayed recovery group had lower average MQS scores and achieved lower IMS levels during their ICU stay than those who recovered earlier. Each increase in MQS was associated with a 49% lower odds of delayed recovery, and each higher point on the IMS was linked to a 14% lower odds of delayed recovery. These results held true after adjusting for age, underlying health conditions, and illness severity.

Interestingly, the early recovery group did not show a significant relationship between rehabilitation parameters and recovery speed, likely because many were already in good physical condition before ICU admission. The findings suggest that the quality of mobilization in the ICU, getting patients to higher levels of activity, may matter more than total exercise time. Purposeful movement, such as sitting up, standing, or walking helps preserve muscle strength and function, supporting faster return to independence. Given that 42% of patients experienced delayed recovery, optimizing ICU rehabilitation programs could have a major impact. Earlier and more intense mobilization could reduce hospital stays, improve quality of life, and lower healthcare costs.

This was a secondary analysis, so causation cannot be proven. The study did not measure certain factors, such as frailty or muscle mass before ICU admission, which may influence recovery. Rehabilitation practices also varied slightly between hospitals. “Our study, reduced rehabilitation dose and mobility intensity during ICU stay were independently associated with delayed ADL recovery among mechanically ventilated patients,” concluded Prof. Watanabe.

Future studies should test standardized, high-dose rehabilitation protocols in a larger group of ICU patients, ideally through randomized trials, to confirm whether increasing rehabilitation dose and intensity can reliably speed recovery. For critically ill patients on mechanical ventilation, rehabilitation focused on higher-dose, higher-intensity mobility exercises in the ICU may help prevent long-term dependence in daily activities. The study highlights an important, modifiable part of ICU care that could improve patient outcomes and independence after discharge.

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About Professor Shinichi Watanabe

Shinichi Watanabe is a rehabilitation specialist based at the National Hospital Organization Nagoya Medical Center in Nagoya, Japan, where he works in the Department of Rehabilitation. He has 45 publications and over 396 citations, with more than 4,000 reads of his work. Watanabe’s expertise spans physical rehabilitation and mobility in critical-care settings, with recent studies exploring early mobilization in intensive-care units (ICUs), quantification of mobilization dose, and functional outcomes in mechanically ventilated patients.