OBJECTIVE: To determine whether intermittent positive-pressure breathing (IPPB) improved lung compliance, work of breathing, and respiratory function in patients with recent high spinal cord injury (SCI). DESIGN: An unblinded randomized crossover trial. SETTING: Rehabilitation hospital. PARTICIPANTS: Patients (N=14) with SCI caused by trauma within the last 6 months and located between C5 and T6. INTERVENTION: Two months of IPPB and 2 months of conventional treatment were evaluated prospectively in random order in patients with SCI. MAIN OUTCOME MEASURES: Noninvasive lung function tests and arterial blood gas measurements were obtained repeatedly in all patients. Repeated measurements of dynamic lung compliance and work of breathing as measured by computing the area enclosed between the inspiratory esophageal pressure-tidal volume curve, and the theoretical chest wall static pressure-volume curve were performed in 7 patients. RESULTS: IPPB had no long-term effects on vital capacity (52.1%+/-11.3% vs 54.5%+/-12.5%, after conventional treatment and IPPB, respectively; P=.27), lung compliance (66.4+/-48.9 mL/cmH(2)O vs 70.3+/-38.4 mL/cmH(2)O; P=.56), or other lung function tests. IPPB did not exert short-term effects on lung compliance or work of breathing. CONCLUSIONS: IPPB produced no immediate or long-term improvements in lung function or ventilatory mechanics in patients with recent SCI. (ClinicalTrials.gov identifier: NCT00476866.).