Titration of PEEP During Mechanical Ventilation in Patients With ARDS Using Electrical Impedance Tomography.

Lung units that participate in gas exchange are known as 'recruited' lung. Patients with lung injury suffer from a proportion of units that do not participate in gas exchange (i.e. the derecruited lung), which results in impaired gas exchange and induces an inflammatory cascade. The level of PEEP is often coupled to indices of oxygenation such as PaO2, PaO2 to FIO2 ratio, or oxygen index. Currently, two strategies are widely accepted and considered equivocal, one strategy using a lower PEEP level coupled to a certain oxygen requirement, the other using a higher PEEP level. The primary purpose of this study is to demonstrate the safety and efficacy of an electrical impedance tomography (EIT) PEEP titration protocol designed to recruit collapsed lung in children with ARDS and properly maintain lung volumes by setting an optimal PEEP level. A safety system has been developed using the ARDSnet FIO2/PEEP High (upper threshold limit) and Low (lower threshold limit) algorithm. Efficacy will be defined as an improvement in lung volume as assessed by electrical impedance tomography, lung compliance and by an improvement in markers of gas exchange. Safety will be defined as the incidence of barotrauma and hemodynamic consequences that occur during the protocol. Those results will be compared to incidences of barotrauma and hemodynamic compromise within the ARDS literature. Knowledge gained from this pilot will be instrumental in developing an EIT imagine guided protocol which will allow us to conduct future RCTs utilizing EIT technology