Airway pressure release ventilation versus pressure-controlled ventilation in acute hypoxemic respiratory failure

Background
Airway pressure release ventilation (APRV) is defined as ventilation modality with triggered time, limited pressure, and cycled time. In this mode, the pressure altered from a high level applied for a prolonged time to maintain adequate lung volumes and alveolar recruitment, to a low level for a short period of time that allows efficient ventilation and CO2 removal.


Patients and methods
Patients with acute hypoxemic respiratory failure were mechanically ventilated, and then, shifted to either synchronized intermittent mandatory ventilation, pressure control (group I) or to APRV (group II). The following parameters were monitored and compared: arterial blood gas measurements, hemodynamic, respiratory mechanics, peak pressure, plateau pressure, mean airway pressure, compliance, minute ventilation, indices of hemodynamic, and tissue perfusion.


Results
This study involved 60 mechanically ventilated patients. Our study demonstrated no significant difference between both groups regarding demographic data. We found that APRV group have better hemodynamic, better oxygenation, lower need for sedation and vasopressors, higher cardiac index, and higher estimated glomerular filtration rate. ICU scores were comparable in both groups, whereas lung injury score significantly decreased with APRV mode in APRV group. Decreased duration of mechanical ventilation, ICU stay, hospital stay, less complication risk, and less mortality rate were seen with APRV mode.


Conclusion
The early application of APRV in patients with acute severe hypoxemic respiratory failure was associated with better hemodynamic, better oxygenation, better respiratory mechanics, less sedation use, better perfusion, lower risk of complication, and a shorter duration of ICU stay. Future research should compare APRV strategies to assign the best management approach.