Reconsidering exercise in critical care: Mechanisms, thresholds, and therapeutic intent

Rehabilitation of patients with and recovering from Critical Illness has been in the spotlight of Critical Care Research for over 2 decades. Yet little progress has been made in defining interventions that address the physical sequalae of critical illness. There is a lack of knowledge describing which patients will benefit from rehabilitation, when to start, what to do or how to quantify the intervention. The lack of an underlying theoretical framework for why rehabilitation with exercise as part of that rehabilitation, should have an impact on patient outcomes, further hinders delineating interventions. If indeed exercise underpins improvements in Physical Function, what constitutes exercise in a patient with or recovering from critical illness?