Abstract Background:Proportional assist ventilation (PAV) is a physiological ventilation mode
with better patient ventilator synchrony. However its role in intubated patients with chronic
obstructive pulmonary disease (COPD) is still not well defined.
Objective:To evaluate the efficacy of PAV mode in intubated patients with COPD exacerbation
in comparison with conventional synchronized intermittent mandatory ventilation (SIMV) mode.
Patients & methods:Fifty COPD patients presented with hypercapnic respiratory failure who are
intubated and ventilated were recruited to the study. After 12 h of assist-control ventilation, 25
patients shifted to SIMV mode (group 1) while the other 25 patients shifted to PAV mode (group
2). Vital signs, gasometric and mechanical parameters, duration of ventilation and intensive care
unit (ICU) stay were measured.
Results:The successful outcome was achieved in 76.0% in group 1 versus 72.0% in group 2.
Significant improvement in vital signs, gasometric and mechanical parameters was observed in all
patients. Comparison between the two groups after 24 h of ventilation showed significantly higher
values in the PAV group for respiratory rate, heart rate, and systolic blood pressure (P< 0.001).
Significantly lower pH (P< 0.01), higher partial arterial carbon dioxide pressure (PaCO2
)
(P< 0.001), significantly lower tidal volume, peak inspiratory pressure, auto-positive end expira-tory pressure (auto-PEEP), missing efforts, inspiratory time over total time (Ti/Ttot), shorter
duration of ventilation and ICU stay were observed in the PAV group (P< 0.01 for each).