There have been a few recent randomised control studies of early mobilisation. The pros seem to be reduced inpatient length of stay, reduced 6-month inpatient days, improved 6-month activities of daily living, and reduced 6-month anxiety and depression scores. The cons seem to be no improvement in 6-month mortality and no overall reduction in healthcare costs.

Have a look on the Cochrane Library of trials. This seems like a particularly good one:

Wolfe KS, Wendlandt BN, Patel SB et al. Long-term survival and health care utilization of mechanically ventilated patients in a randomized controlled trial of early mobilization. American journal of respiratory and critical care medicine. 2013 (187).

An upper classmate of mine implemented an EBP project related to this three years ago. Her presentation was astounding. It ended with a short video of her team ambulatory a morbidly obese woman 10 meters. The biggest challenge to implementing was the manpower necessary to provide the service. If you message me directly I can get you in touch with her.

I would recommend you spend some time on the ICULiberation web site and icudelirium.org.  Both of these have some great resources for implementing early mobility on ventilated patients.  Vanderbilt University Hospital in the US has been a leader in this area and published some of their results.

It is possible to do this in smaller hospitals but it takes alot of coordination between services-nursing, resp therapy, physical therapy-to make it work. But its worth it. We schedule it the day before so all players can plan & be there ready to go. Less delirium, fewer days on the vent. 

You need to define what "early" is and what resources you have to facilitate this; respiratory therapy, PT, nursing, perfusion and how this fits into their workflow. Early planning is essential and early mobility is key to recovery and ventilator liberation.

Will agree with Donna in that the definition of early can be subjective. Nonetheless, it's pretty clear that mobilizing ventilated patients, even some ECMO patients, favors "early" liberation (or should I say it facilitates liberation, period.). Vandy has been the leader in this area and I know they have had great success with it and we also, are seeing favorable results at our institution.