CHAPTER 22: Early Mobilization and Rehabilitation in Critically Ill Patients

KEY POINTS

• Survivorship from critical illness, regardless of the cause of critical illness, may include substantial neuromuscular weakness that can persist for many years following the index hospitalization.

• Immobility can commonly accompany supportive care. Understanding the effects of bed rest and immobility on muscle, heart, and nervous system is necessary to balance the risks and benefits of early mobilization.

• Early mobilization and rehabilitation can be performed safely despite ongoing critical illness. Safety management screening focuses on three major domains: neurological, respiratory, and cardiovascular stability, but other factors must be considered for the individual.

• Innovative programs have safely implemented early mobility in patients with extensive extracorporeal support devices, such as continuous renal replacement therapy and temporary circulatory support.

• Successful early mobility and rehabilitation programs include standardized scales for measuring mobility milestones, simple and well understood daily mobility goals, and enhanced team communication strategies to ensure rehabilitation is a priority and barriers are addressed.

• Alternative strategies for mobilization include cycle ergometry, neuromuscular stimulation, and functional electrical stimulation with cycling.

INTRODUCTION—SURVIVORSHIP AND WEAKNESS

More than 4 million patients are admitted to ICUs in the United States each year. Innovations in ICU care have resulted in yearly reductions in hospital mortality from critical illness, particularly sepsis; nearly 80% to 90% of critically ill patients survive.^1–3 However, these same data reveal a sizable number of ICU survivors are not returning home to functional lives post ICU. Tragically, a high proportion of survivors experience significant cognitive, psychological, and physically disabling side effects of their critical illness, regardless of their admitting diagnosis.^4,5 These impairments are substantial and can be persistent, resulting in measurable loss of independence and reduced quality of life among ICU survivors.

Weakness is a common problem. Arising from an interaction of inflammatory and metabolic changes due to critical illness, it is theorized to be exacerbated by the detrimental effects of prolonged bedrest commonly imposed on ICU patient care.⁶ ICU-acquired weakness occurs in approximately 50% of patients with sepsis, multiple organ failure, or prolonged mechanical ventilation.⁷ Furthermore, such weakness is associated with prolonged hospitalization, delayed weaning, and increased mortality. ICU follow-up data consistently show persistent functional limitation resulting in only 50% of patients returning to employment at one year post ICU, difficulty performing activities of daily living and only reaching 60% to 65% of functional exercise capacity at 12 months.^8–10 Survivors report that prolonged weakness and loss of function associated with ICU are the most concerning disabilities they experience.¹¹ ‘Survivorship’, or addressing impaired quality of life in ICU survivors has been named ‘the defining challenge of critical care’ for this century.¹²

The benefits of physical activity for improving longevity, physical functioning, and cognitive vitality in non-ICU patients are well established, even for people with chronic ailments such as heart disease and cancer. Historically, critically ill patients had not been considered appropriate for early physical activity because ...