Comparisons of respiratory mechanics in patients under different variations of noisy pressure support ventilation...

Compared with conventional pressure support ventilation (PSV), noisy PSV offers a certain degree of pressure variability, which might benefit the process of weaning from mechanical ventilation. We investigated respiratory mechanics under different levels of variation during the weaning phase in patients receiving noisy PSV to identify the optimal level of variation.

This self-controlled before-and-after study of mechanically ventilated patients in the weaning phase was conducted from September 2020 to October 2022. Each eligible patients received noisy PSV with 0%, 15%, 25%, or 35% variation in a random order. Their respiratory mechanics were collected 1 h after the pressure variation level was switched and compared.

The study found that noisy PSV significantly improved patients' respiratory system compliance at variation levels of 25% and 35% (0% vs. 15% vs. 25% vs. 35%: 40 vs. 38.1 vs. 42.3 vs. 44.5 mL/cmH₂O, P=0.005). Importantly, subgroup analysis revealed this improvement was more pronounced in chronic obstructive pulmonary disease (COPD) patients (0% vs. 15% vs. 25% vs. 35%: 40 vs. 38.4 vs. 45 vs. 50, P=0.03). At the same time, at variability levels of 25% and 35%, patients' inspiratory trigger delay time was also significantly shorter (0% vs. 15% vs. 25% vs. 35%: 140 vs. 100 vs. 100 vs. 100 ms, P<0.001). In addition, the PeakArea was significantly lower at variation 35% (8.8±2.5 cmH₂O·s).

Pressure variation at level of 25% or 35% could improve patients' respiratory system compliance and shorten the inspiratory trigger delay time, potentially being optimal in noisy PSV during the weaning phase from mechanical ventilation.