Evaluation of a new circuit configuration for the VDR-4 high-frequency percussive ventilator.

High-frequency percussive ventilation (HFPV) by the VDR-4(R) has been a successful mode of ventilation in the management of inhalation injuries for nearly 20 years. A limitation of the standard VDR-4 ventilator circuit is that the sliding venturi manifold is heavy in weight and is normally connected directly to the patient's endotracheal tube (ETT), resulting in potentially hazardous torque on the ETT. In this study, we evaluate the mechanics of a new circuit for the VDR-4 that relocates the sliding venturi manifold portion of the circuit away from the ETT into the ventilator proper. This new VDR-4 circuit configuration may have an important impact on patient safety.