Chest compression with a higher level of pressure support ventilation: effects on secretion removal, hemodynamics, and respiratory mechanics in patients on mechanical ventilation

Objective: To determine the efficacy of chest compression accompanied by a 10-cmH(2)O increase in baseline inspiratory pressure on pressure support ventilation, in comparison with that of aspiration alone, in removing secretions, normalizing hemodynamics, and improving respiratory mechanics in patients on mechanical ventilation. Methods: This was a randomized crossover clinical trial involving patients on mechanical ventilation for more than 48 h in the la of the Porto Alegre Hospital de Clinicas, in the city of Porto Alegre, Brazil. Patients were randomized to receive aspiration alone (control group) or compression accompanied by a 10-cmH(2)O increase in baseline inspiratory pressure on pressure support ventilation (intervention group). We measured hemodynamic parameters, respiratory mechanics parameters, and the amount of secretions collected. Results: We included 34 patients. The mean age was 64.2 +/- 14.6 years. In comparison with the control group, the intervention group showed a higher median amount of secretions collected (1.9 g vs. 2.3 g; p = 0.004), a greater increase in mean expiratory tidal volume (16 +/- 69 mL vs. 56 +/- 69 mL; p = 0.018), and a greater increase in mean dynamic compliance (0.1 +/- 4.9 cmH(2)O vs. 2.8 +/- 4.5 cmH(2)O; p = 0.005). Conclusions: in this sample, chest compression accompanied by an increase in pressure support significantly increased the amount of secretions removed, the expiratory tidal volume, and dynamic compliance.