Evaluation of an automated PEEP controller in mechanical ventilation support

Abstract

Mechanical ventilation implies the risk of ventilator induced lung injury (VILI). One of the goals of mechanical ventilation is to sustain alveolar recruitment while avoiding excessive lung inflation. To achieve this goal the patient should be ventilated within that range of the PV-loop, where the compliance of the respiratory system is maximal. A PEEP controller was designed to adapt the PEEP setting such as the patient is ventilated within the range of maximal compliance. This method was implemented in the automatic ventilator control system AUTOPILOT-BT. To evaluate and test such a complex system with different interacting components a realistic test bed is required. An experimental setup was created including physical lung simulators. Two different simulators were tested before they were selected for the evaluation of the PEEP controller. The PEEP-controller is able to identify the appropriateness of six shape categories which quantitatively describe the shape of the compliance-volume curve on each PEEP-level. If the shape doesn't correspond to the maximal compliance, the Autopilot-BT titrates the PEEP until the target shape is obtained. The AUTOPILOT-BT system might help to avoid excessive lung inflation as well as underinflation in mechanical ventilation support by obtaining maximal compliance. © 2009 Springer Berlin Heidelberg.