The purpose of this pilot study is to test the feasibility of two turning protocols and study procedures for a multi-site randomized clinical trial to evaluate efficacy and safety of horizontal positioning interventions to reduce pulmonary complications in mechanically ventilated critically ill adult patients. The hypothesis of the randomized controlled trial (RCT) is no difference in pulmonary complications between manual, 2-hourly lateral rotation to > 45 degrees (control), and continuous automated turning to 45 degrees (experimental) groups.