Comparison Between Different Ventilator Hyperinflation Maneuvers

PURPOSE: To compare different ways of applying ventilator hyperinflation. METHODS: A randomized crossover clinical trial was performed with 30 patients (66.5 ± 17.3 years) with hypersecretion. The ventilator hyperinflation was performed in five ventilatory modalities for five minutes, with an interval of 2 hours, the order being determined by randomization: controlled ventilation at volume (VCV) with constant flow of 20 (VCV20) Lpm and 40 Lpm (VCV40), controlled ventilation pressure ventilation (PCV), controlled pressure ventilation associated with inspiratory time adjustment (PCV + Tins) and support pressure ventilation (PSV). In VCV mode, the volume was increased every 50mL, until reaching a maximum pressure of 40cmH2O. In the pressure controlled modes, the inspiratory pressure was increased every 5 cmH2O until the total pressure reached 40 cmH2O. The inspiratory time was adjusted so that the inspiratory flow reached the baseline. The following variables were evaluated: tidal volume, inspiratory time (Tins), mean airway pressure (Pmean), peak inspiratory flow (PIFR) and expiratory flow (PEFR), PIFR / PEFR and Bias Flow (PEFR-PIFR).