Early mobilization and recovery in mechanically ventilated patients in the ICU: a bi-national, multi-centre, prospective cohort study

Abstract

Introduction: The aim of this study was to investigate current mobilization practice, strength at ICU discharge and functional recovery at 6 months among mechanically ventilated ICU patients.

Method: This was a prospective, multi-centre, cohort study conducted in twelve ICUs in Australia and New Zealand. Patients were previously functionally independent and expected to be ventilated for >48 hours. We measured mobilization during invasive ventilation, sedation depth using the Richmond Agitation and Sedation Scale (RASS), co-interventions, duration of mechanical ventilation, ICU-acquired weakness (ICUAW) at ICU discharge, mortality at day 90, and 6-month functional recovery including return to work.

Results: We studied 192 patients (mean age 58.1 ± 15.8 years; mean Acute Physiology and Chronic Health Evaluation (APACHE) (IQR) II score, 18.0 (14 to 24)). Mortality at day 90 was 26.6% (51/192). Over 1,351 study days, we collected information during 1,288 planned early mobilization episodes in patients on mechanical ventilation for the first 14 days or until extubation (whichever occurred first). We recorded the highest level of early mobilization. Despite the presence of dedicated physical therapy staff, no mobilization occurred in 1,079 (84%) of these episodes. Where mobilization occurred, the maximum levels of mobilization were exercises in bed (N = 94, 7%), standing at the bed side (N = 11, 0.9%) or walking (N = 26, 2%). On day three, all patients who were mobilized were mechanically ventilated via an endotracheal tube (N = 10), whereas by day five 50% of the patients mobilized were mechanically ventilated via a tracheostomy tube (N = 18).

Conclusions: Early mobilization of patients receiving mechanical ventilation was uncommon. More than 50% of patients discharged from the ICU had developed ICU-acquired weakness, which was associated with death between ICU discharge and day-90.

Clinical trial registration: ClinicalTrials.gov NCT01674608. Registered 14 August 2012.

Figure 1

Flow of patients through the study.

Figure 2

Flow of included patients through the study from days 1 to 14. Data for the number of patients invasively ventilated and mobilising (active), invasively ventilated and inactive, dead, extubated or discharged from the ICU.

Figure 3

Maximum level of activity in invasively ventilated patients for days 1 to 14. Measured using the ICU mobility scale, where 0 = no activity, 1 = exercises in bed, 2 = passively moved to the chair, 4 = sitting on the edge of the bed, 5 = standing, 6 = transferring from bed to chair through standing, 7 = marching on the spot, 8 = walking with assistance of two people, 9 = walking with assistance of one person and 10 = walking independently.

Figure 4

Survival to day 90 in patients who survived to ICU discharge and were diagnosed with ICU-acquired weakness compared with patients without ICU-acquired weakness. ICUAW, ICU-acquired weakness.