Effects of chest compression on secretion removal, lung mechanics, and gas exchange in mechanically ventilated patients. [Carta]: a crossover, randomized study - Gonçalves, Elaine Cristina; Souza, Hugo Celso Dutra de; Tambascio, Joana; Almeida, Marcelo Barros; Basile Filho, Aníbal; Gastaldi, Ada Clarice (Intensive Care Medicine, 2016)