Open lung approach versus standard protective strategies: Effects on driving pressure and ventilatory efficiency during anesthesia - A pilot, randomized controlled trial

PLoS One. 2017 May 11;12(5):e0177399. doi: 10.1371/journal.pone.0177399. eCollection 2017.

Abstract

Background: Low tidal volume (VT) during anesthesia minimizes lung injury but may be associated to a decrease in functional lung volume impairing lung mechanics and efficiency. Lung recruitment (RM) can restore lung volume but this may critically depend on the post-RM selected PEEP. This study was a randomized, two parallel arm, open study whose primary outcome was to compare the effects on driving pressure of adding a RM to low-VT ventilation, with or without an individualized post-RM PEEP in patients without known previous lung disease during anesthesia.

Methods: Consecutive patients scheduled for major abdominal surgery were submitted to low-VT ventilation (6 ml·kg-1) and standard PEEP of 5 cmH2O (pre-RM, n = 36). After 30 min estabilization all patients received a RM and were randomly allocated to either continue with the same PEEP (RM-5 group, n = 18) or to an individualized open-lung PEEP (OL-PEEP) (Open Lung Approach, OLA group, n = 18) defined as the level resulting in maximal Cdyn during a decremental PEEP trial. We compared the effects on driving pressure and lung efficiency measured by volumetric capnography.

Results: OL-PEEP was found at 8±2 cmH2O. 36 patients were included in the final analysis. When compared with pre-RM, OLA resulted in a 22% increase in compliance and a 28% decrease in driving pressure when compared to pre-RM. These parameters did not improve in the RM-5. The trend of the DP was significantly different between the OLA and RM-5 groups (p = 0.002). VDalv/VTalv was significantly lower in the OLA group after the RM (p = 0.035).

Conclusions: Lung recruitment applied during low-VT ventilation improves driving pressure and lung efficiency only when applied as an open-lung strategy with an individualized PEEP in patients without lung diseases undergoing major abdominal surgery.

Trial registration: ClinicalTrials.gov NCT02798133.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Anesthesiology / methods*
  • Capnography
  • Female
  • Humans
  • Lung / physiology*
  • Male
  • Middle Aged
  • Positive-Pressure Respiration*
  • Tidal Volume

Associated data

  • ClinicalTrials.gov/NCT02798133

Grant support

This work was funded by the INCLIVA Biomedical Research Institute.