A Comparison of Optimal PEEP Determination Guided by EIT and Conventional Protective Ventilation Tool in ARDS Patients

Acute respiratory distress syndrome (ARDS)，over the years in the treatment policy has been confirmed that: with low tidal volume to achieve lung protection strategy and high positive end-expiratory pressure (PEEP), both can effectively reduce the mortality rate. And increase PEEP，the alveolar pressure is greater than the atmospheric pressure when exhaled，So that can be effective expansion of the lungs to avoid spitting at the end of the alveolar collapse.

The study of PEEP in the setting mode has not yet been conclusive. Currently in the clinical situation，there are several ways to choose the best PEEP mode for ARDS patients. In this study the investigators selected two best PEEP assessment methods to compare:

First is using the conventional postive ventilator to choose optimal and the new non-invasive electrical impedance tomography guided method and evaluation the treatment outcome in moderate and severe acute respiratory distress syndrome patients by using pressure-volume curve guided and electrical impedance tomography guided positive end-expiratory pressure setting. In this project, the investigators utilize a newly available non-invasive method- electric impedance tomography (EIT) and Protective Ventilation to determine the optimal PEEP on ARDS patients required invasive mechanical ventilator support in ICU at the Far Eastern memorial hospital, Taiwan.

Inclusion criteria

• Moderate to severe ARDS patient on mechanical ventilation from ER or word transfer ICU. (P/F≦ 200 with PEEP ≥ 5cmH20) (PEEP greater than or equal to 5 cm H2O and Berlin criteria for ARDS)

Exclusion criteria

• On pacemaker
• Pregnant
• Thoracic or spinal cord trauma
• Pneumothorax
• Hemodynamic instability
• IICP