2005 OPEN FORUM Abstracts
USING THE PRESSURE-VOLUME (P/V) CURVE TO SET PROPER PEEP IN ACUTE LUNG INJURY.
Joseph DiRocco MD, David Carney MD,Kathy Snyder, Gary Nieman Upstate Medical University, Department of Surgery, Syracuse, NY
Background: Mechanical ventilation if applied improperly will significantly increase the mortality in patients with ARDS. A current strategy of protective mechanical ventilation is known as the "Open Lung Approach". Open lung ventilation is accomplished by first inflating atelectatic areas of lung with a recruitment maneuver and then adding sufficient PEEP to keep the newly inflated alveoli patent. However, the level of PEEP necessary to prevent recollapse of alveoli is currently under debate.
Methods: We used the PubMed database and reviewed studies that utilized the P-V curve to identify optimal PEEP. In addition, we reviewed the findings in our laboratory viewing alveoli using an in vivo microscope (DiRocco et al, Am J Resp Crit Care Med. 2005;2:A545, Fig).
Results: Early studies suggest that PEEP should be set on the lower inflection point (LIP) on the inflation limb of the P-V curve, however, more recent studies suggest that PEEP should be set at the upper inflection point (UIP) on the deflation limb. Our work supports the latter hypothesis (Figure).
Conclusions: The optimal place to set PEEP when using an "Open Lung Approach" ventilation strategy is at the UIP on the deflation limb of the P-V curve.