Selecting the best ventilator hyperinflation technique based on physiologic markers: A randomized controlled crossover study

Background: Ventilator hyperinflation (VHI) is effective in improving respiratory mechanics, secretion removal, and gas exchange in mechanically ventilated subjects; however, there are no recommendations for the best ventilator settings to perform the technique. Objective: To compare six modes of VHI, concerning physiological markers of efficacy and safety criteria to support the selection of optimal settings. Methods: Thirty mechanically ventilated patients underwent six modes of VHI in a randomized order. The delivered volume, expiratory flow bias criteria, overdistension, patient-ventilator asynchronies and hemodynamic variables were assessed during the interventions. Results: Volume-controlled ventilation with inspiratory flow of 20 lpm (VC-CMV20) and pressure support ventilation (PSV) achieved the best effectiveness scores (P < 0.05). The target peak pressure of 40 cmH(2)O was associated with a high incidence of overdistension. PSV showed a lower incidence of patient-ventilator asynchronies. Conclusions: The modes VC-CMV20 and PSV are the most effective for VHI. Alveolar overdistension and patient-ventilator asynchronies must be considered when applying VHI. (C) 2018 Elsevier Inc. All rights reserved.