ABSTRACT: IMPORTANCE:Physical rehabilitation in the intensive care unit (ICU) may improve the outcomes of patients with acute respiratory failure. OBJECTIVE:To compare standardized rehabilitation therapy (SRT) to usual ICU care in acute respiratory failure. DESIGN, SETTING, AND PARTICIPANTS:Single-center, randomized clinical trial at Wake Forest Baptist Medical Center, North Carolina. Adult patients (mean age, 58 years; women, 55%) admitted to the ICU with acute respiratory failure requiring mechanical ventilation were randomized to SRT (n=150) or usual care (n=150) from October 2009 through May 2014 with 6-month follow-up. INTERVENTIONS:Patients in the SRT group received daily therapy until hospital discharge, consisting of passive range of motion, physical therapy, and progressive resistance exercise. The usual care group received weekday physical therapy when ordered by the clinical team. For the SRT group, the median (interquartile range [IQR]) days of delivery of therapy were 8.0 (5.0-14.0) for passive range of motion, 5.0 (3.0-8.0) for physical therapy, and 3.0 (1.0-5.0) for progressive resistance exercise. The median days of delivery of physical therapy for the usual care group was 1.0 (IQR, 0.0-8.0). MAIN OUTCOMES AND MEASURES:Both groups underwent assessor-blinded testing at ICU and hospital discharge and at 2, 4, and 6 months. The primary outcome was hospital length of stay (LOS). Secondary outcomes were ventilator days, ICU days, Short Physical Performance Battery (SPPB) score, 36-item Short-Form Health Surveys (SF-36) for physical and mental health and physical function scale score, Functional Performance Inventory (FPI) score, Mini-Mental State Examination (MMSE) score, and handgrip and handheld dynamometer strength. RESULTS:Among 300 randomized patients, the median hospital LOS was 10 days (IQR, 6 to 17) for the SRT group and 10 days (IQR, 7 to 16) for the usual care group (median difference, 0 [95% CI, -1.5 to 3], P?=?.41). There was no difference in duration of ventilation or ICU care. There was no effect at 6 months for handgrip (difference, 2.0 kg [95% CI, -1.3 to 5.4], P?=?.23) and handheld dynamometer strength (difference, 0.4 lb [95% CI, -2.9 to 3.7], P?=?.82), SF-36 physical health score (difference, 3.4 [95% CI, -0.02 to 7.0], P?=?.05), SF-36 mental health score (difference, 2.4 [95% CI, -1.2 to 6.0], P?=?.19), or MMSE score (difference, 0.6 [95% CI, -0.2 to 1.4], P?=?.17). There were higher scores at 6 months in the SRT group for the SPPB score (difference, 1.1 [95% CI, 0.04 to 2.1, P?=?.04), SF-36 physical function scale score (difference, 12.2 [95% CI, 3.8 to 20.7], P?=?.001), and the FPI score (difference, 0.2 [95% CI, 0.04 to 0.4], P?=?.02). CONCLUSIONS AND RELEVANCE:Among patients hospitalized with acute respiratory failure, SRT compared with usual care did not decrease hospital LOS. TRIAL REGISTRATION:clinicaltrials.gov Identifier: NCT00976833.