Question: What level of noninvasive positive airway pressure is able to expand the lungs of
people with pleural drainage? Design: Cross-sectional, experimental and randomized study.
Participants: Four consecutive people with pleural effusion drained within 24 hours, with
controlled pain and without contraindications to use of noninvasive positive pressure.
Intervention: Each person will be randomly subjected to three levels of noninvasive positive
airway pressure: 0 (zero), 4 and 15 cmH2O for evaluation via chest computed tomography.
Outcome measures: Lung area.