• Ultimately, despite much research, the best method to set PEEP in patients with ARDS remains uncertain
  • Several approaches have been suggested each with their own merits and problems:

    Method

    Steps

    Adjust according to FiO2

    • PEEP is adjusted according to the FiO2
    • Protocols describe the use of PEEP tables to match the PEEP with the FiO2 – including that used in the original ARDSNET trial[AC1]

    Lower Inflection point

    • The pressure-volume loop can be used to determine the "critical opening pressure" of the alveoli
    • PEEP can then be set to something slightly above this.

    Maximal Static Compliance

    • PEEP can be adjusted up or down to determine the maximal compliance
    • Can be used in conjunction with a recruitment manoeuvre with PEEP decreased in 2cm H2O decrements and the point of maximal compliance determined

    CT of the Chest

    • CT scans can be used to visually determine the PEEP level which recruits the optimal amount of lung
    • Usually reserved for the use of research purposes

    Oesophageal Balloon Manometry

    • Transpulmonary pressures can be used to establish transpulmonary pressures and optimise PEEP