Redefining Survivorship: POWER to Maximize Physical Function for Survivors of Critical Illness

Overview

Patients surviving critical illness experience significant skeletal muscle dysfunction and weakness. Muscle atrophy suffered during critical illness has a long-term impact on the functionality and mobility of these individuals. As a result, individuals surviving critical illness have a significant reduction in quality of life, even up to 5 years post discharge. Research including large randomized controls demonstrates that rehabilitation focused on active mobilization may positively influence patient outcomes. Thus, early mobilization is an important intervention that has many purported benefits. Current rehabilitation practice in the intensive care unit (ICU) and recommendations from clinical practice guidelines such as the Society of Critical Care Medicine, PADIS Guidelines support these interventions to reduce the detrimental effects of immobilization during critical illness. Early mobilization is routinely thought of as standard of care for patients admitted for acute respiratory distress syndrome and sepsis. However, a significant number of recent randomized controlled trials implementing early rehabilitation and mobilization interventions fail to demonstrate immediate or long-term benefits.10,11,18,19 Interesting, active mobilization and rehabilitation analyzed in systematic review had no impact on mortality and "no consistent effects of function, quality of life and ICU or hospital length of stay."18 There are a few potential explanations for interventions not leading to reduction in impairment or functional benefit. Scientific Premise: From our preliminary data (Figure 1) and my clinical experience, a significant cause of the physical impairments in these patients is reductions in muscular power. Muscular power is a critical determinant of functional mobility.20 Preliminary data demonstrate that lower extremity muscle power is significantly reduced in this population and furthermore, these deficits are strongly correlated to physical function. Muscle power training is a potential therapeutic intervention that could lead to more robust improvements in physical function. This concept has been explored extensively in community-dwelling older adults. A recent systematic review of controlled trials demonstrates that power training is superior to traditional resistance training at improving functional performance when comparing the two training modalities.21 Furthermore, power training is feasible for older adults and clinical populations of Parkinson's Disease, Stroke, and frailty.22-27 Thus the feasibility and pragmatic nature of power training is not a concern. Of interest, a randomized controlled trial was completed in institutionalized frail nonagenarians (\>85 years or older).27 In this study, no patients drop-out of study due to power training and significant benefits in function were achieved.27 Therefore, the investigators propose a interventional trial to study the effect of a standardized muscle power training program for patients admitted to the ICU for critical illness.