Longer-term cognitive impairment at 12 months in mechanically ventilated intensive care patients can be reduced through early mobilisation
The potential for long-term cognitive impairment (CP) among mechanically ventilated patients within an intensive care unit can be significantly reduced through early mobilisation according to the findings of a randomised trial by researchers at the University of Chicago, Chicago, USA.
Patients in both medical and surgical intensive care units are at a high risk of long-term cognitive impairment. In fact, after only two days of documented delirium, at 12 months, 71% of survivors had cognitive impairment and of whom, 36% had severe impairment. While delirium commonly occurs in critical illness, whether this causes longer-term cognitive impairment is less clear. Delirium can be reduced through early mobilisation, i.e., whole-body rehabilitation with interruption of sedation and physical and occupational therapy in the earliest days of critical illness. However, no studies have examined whether early mobilisation also positively impacts on the longer-term development of CP.
In the current study, the US team performed a randomised trial of early mobilisation among functionally independent and mechanically ventilated patients admitted to the ICU versus usual care to determine if this reduced cognitive impairment, 12 months after the critical illness. Adult patients admitted to the ICU intensive-care unit (ICU), were randomised 1:1 to either early physical and occupational therapy (i.e., early mobilisation) or usual care. The primary outcome, cognitive impairment 1 year after hospital discharge, was assessed using the Montreal Cognitive Assessment (MoCA) scale and on which, CP is deemed to be present if the score is < 26.
Cognitive impairment and early mobilisation
A total of 198 patients with mean age of 56.2 years (42.5% female) were equally randomised to early mobilisation or usual care.
When assessed after 12 months, the rate of CP among those assigned to early mobilisation was 24% (mean MoCA score = 26) compared with 43% (mean MoCA score = 23) with usual care and this difference was statistically significant (p = 0.0043). In fact, CP was also significantly lower upon hospital discharge, (54% vs 69%, p = 0.029). The early mobilisation group also had significantly fewer ICU-acquired weaknesses (p = 0.0001) and higher physical component quality-of-life scores (p < 0.0001). However, there were no significant differences in the rates of functional independence or mental component scores between groups after 12 months.
The authors concluded that early mobilisation could be the first known intervention to improve long-term cognitive impairment among ICU patients following mechanical ventilation.
Patel BK et al. Effect of early mobilisation on long-term cognitive impairment in critical illness in the USA: a randomised controlled trial. Lancet Respir Med 2023