not result in improved patient-centered outcomes when tested in a larger trial [7, 8]. More importantly, it has been difficult to test this complex intervention, with several randomized trials delivering significantly less early mobilization than specified in the study protocol [2, 9] and observational studies reporting very low rates of early mobilization during the ICU stay [10, 11]. This chapter summarizes the considerations for patient safety during early mobilization; including the physiological assessment of the patient, the consideration of invasive lines and monitoring, the management of sedation, strategies to educate and manage the multidisciplinary team and environmental factors. Importantly, we will consider the long-term effect of early mobilization on patient outcome and the future directions for this important area of work for ICU clinicians. Safety of Early Mobilization in the ICU: Short-Term Consequences Early mobilization is a complex intervention that requires careful patient assessment and management, as well as interdisciplinary team cooperation and training [12]. Patient safety is one of the most commonly reported barriers to delivering early mobilization, including respiratory, cardiovascular and neurological stability and the integrity of invasive lines. In a recent systematic review and metaanalysis of patient safety during early mobilization, 48 studies were identified that reported data on safety during early mobilization, including falls, removal of endotracheal tubes (ETT), removal or dysfunction of intravascular catheters, removal of catheters or tubes, cardiac arrest, hemodynamic changes and oxygen desaturation [13]. Five studies were not included as their data were reported in other included publications. The 43 included studies had different descriptions of safety events and, in most, the criteria for ceasing early mobilization were the same