For those of you who have been following the blog, you might remember that I recently detailed some new studies investigating early mobility in critically ill patients (See blog post here: Is Early Mobility in the ICU at a Standstill?). This week, another new study was published, this one in The Lancet (Schaller SJ, et al. Lancet. 2016;388(10052):1377-1388). This randomized study found benefit from early mobilization in critically ill surgical patients enrolled from 5 international ICUs (3 in US, 1 in Austria, 1 in Germany). I’d like to use this opportunity to discuss the methodology and results of this study and my current thoughts on early mobility in critically ill patients.
This study randomized 200 patients ventilated for fewer than 2 days and expected to be ventilated longer than another day to standard treatment or mobilization intervention. The mobilization intervention utilized both closed loop communication and a targeted mobility optimization score. The results appear great on face value: early mobility resulted in a higher mobility optimization score, shorter ICU lengths of stay, and functional independence score at hospital discharge. Many proponents will point to the early initiation of the intervention, the goal-directed nature of the mobility intervention, and standardized critical care, including daily spontaneous awakening trials in all patients. While these are important differences from two recent negative studies of mobility, we should also take note of some other differences. First, and most obvious, these are post surgical patients – which means they have fewer comorbidities. Furthermore, only patients who were functionally independent at baseline were enrolled. In addition, patients who were hospitalized for more than 5 days prior to ICU admission or who had a motor component of the GCS less than 5 (at least localizes to painful stimuli with 6 being following commands) were excluded. These exclusions may have a significant role in explaining the apparent disparate results. Identifying the appropriate patients to aggressively try to intervene with early mobility is important. Trying to broadly apply this labor intensive treatment modality to all ICU patients is likely not going to be beneficial in many patients.
Lastly, while these outcomes are intriguing, they weren’t all positive. While the ICU length of stay (and time to ICU discharge readiness) was shorter, there wasn’t any difference in long-term (i.e. 3 month) strength or quality of life. Mortality also wasn’t statistically different, although it trended in the wrong direction – and remember that hospital (or ICU) mortality confounds lengths of stay analyses – patients who die early have really short lengths of stay (and this is an example of when short length of stay is not a positive outcome).
All of this is progress. Progress in the fact that we need to keep studying early mobility. We need to better identify patients and populations that this resource intensive intervention is likely to benefit. Might that be functionally independent surgical critically ill patients with relatively few mobilities and short hospital stays prior to ICU admission? This study suggests that this population may be one we should be targeting more aggressively for early mobility. Hopefully future studies will identify additional critically ill patient populations who may benefit from early mobility.