An Evaluation of Various Inspiratory Times and Inflation Pressures During Airway Pressure Release Ventilation.
There are few recommendations how best to apply certain modes of mechanical ventilation, and the application of Airway Pressure Release Ventilation (APRV) requires strategic implementation of specific inspiratory (I-time) and expiratory times (E-time) and particular mean airway pressures (MAWP), neither of which is standardized. We sought to identify whether an ideal I-time or MAWP could be identified to favor more positive clinical outcomes.
A retrospective analysis of archived electronic health record data to evaluate the clinical outcomes of adult patients that had been placed on APRV for a target of at least 8 hours. 68 adult subjects were evaluated from a convenient sample.
All outcomes of interest (surrogates) for short-term clinical outcomes to include the PaO2/FiO2 (P/F) ratio, Oxygen Index (OI), Oxygen Saturation Index (OSI), and Modified Sequential Organ Failure Assessment (MSOFA) scores showed improvement after at least approximately 8 hours on APRV. Most notably, there was significant improvement in P/F ratio (p = 0.012) and OSI (p = 0.000). Results of regression analysis showed MAWP as a significant positive predictor of post-APRV OSI and P high as a significant positive predictor of post-APRV MSOFA score.
In summary, it was found that settings for P high, Plow, and T low in addition to overall MAWP and Body Mass Index (BMI) had significant correlation to impact at least one of the short-term clinical outcomes measured with a lower setting for both P high and MAWP predictive of a better post-APRV OSI and MSOFA score.