Purpose of Review
Bed rest was a treatment recommended for critically ill patients admitted to the intensive care unit (ICU) that aimed to minimize energy expenditure, permit wound healing and minimize somatic stressors. However, evidence demonstrates that bed rest leads to disuse atrophy, which may be compounded by premorbid sarcopenia and ICU-acquired weakness (ICUAW). ICUAW partly results from muscle breakdown and systemic inflammation and may exacerbate critical illness. Coupled with analgosedation, ICUAW may prolong mechanical ventilation (Kho et al. in BMJ Open Respir Res. 2019;6(1) 2019; Maffei et al. in Arch Phys Med Rehabil. 2017;98 2017; McWilliams et al. in J Crit Care. 2018;44 2018; Sarfati et al. in J Crit Care. 2018;46 2018), increase risk of venous thromboembolism (Denehy et al. in Intensive Care Med. 2017;43(1) 2017; Lyles in J Am Geriatr Soc. 1988;36(11) 1988) create dependence on vasopressor agents (Lyles in J Am Geriatr Soc. 1988;36(11) 1988; Fortney et al. in Comprehen Physiol. 1996) restrict joint mobility, and induce pressure injuries. Neurologically injured patients may be at a higher risk of ICUAW than other critically-ill patients, given that neurological injury itself results in weakness, which may be focal or generalized. Early mobilization (EM), typically defined as physical therapy within 72 h of ICU (Cumming et al. in Neurology. 2019;93(7) 2019), may preempt or mitigate these deleterious consequences of critical care.
Recent Findings
Retrospective data suggest that EM protocols reduce ventilator days, decrease venous thromboembolism, avert pressure wounds, and reduce the length of stay. EM may reduce the incidence, duration, and severity of delirium (Morris et al. in Crit Care Med. 2008;36(8) 2008; Needham et al. in Arch Phys Med Rehabil. 2010;91(4) 2010). Larger and more rigorous studies have not demonstrated benefit of EM on outcomes after critical care; some have demonstrated harm. Neurologically injured critical care patients have generally been excluded from early mobilization protocols due to safety concerns that stem from the increased potential for falls, disorders of consciousness, cognitive impairment, intracranial hypertension, and potential dislodgment of intracranial devices. Notably, data from patients with ischemic stroke suggest that EM may also be associated with harm in this group.
Summary
EM may benefit neurologically injured patients once acute ischemia, elevated ICP, and seizures are resolved. Targeting moderate acuity patients may be critical to improving outcomes and optimizing resource utilization in this resource-intensive intervention. The duration of mobility session, optimal frequency of mobility session, and timing of session remain to be determined.
