Abstract 84: Continuous Passive Ventilation With Airway Pressure-Aided CPR
Airway control devices during CPR have shown efficacy improving hemodynamics and survival. For example, the Impedance Threshold Device (ITD), employ a negative thoracic pressure during the decompression phase of CPR, which draws blood into the thorax, and better primes the thoracic pump. However, ventilation accompanying these devices is delivered with a relatively long and profound positive pressure that disrupts the beneficial vacuum of the ITD. Proposed here is a method to achieve vacuum while providing passive ventilation, continuously.
Methods: An electronic valve was constructed to occlude the airway at appropriate times, synchronized to the CPR compressions. Per the figure below, (right), the synchronized airway valve (SAV) CPR is delivered in couplets. The first peak shown is a compression delivered with a closed airway, to achieve good thoracic ejection. The second peak is a compression with an open airway, allowing pulmonary gas exit (orange dots). A pause follows with the valve closed, creating thoracic vacuum, enabling ITD benefits. At the end of this pause, the valve is opened, allowing air or passively insufflated oxygen to enter (blue dots). The cycle then repeats. A hydro-pneumatic cardiopulmonary model was constructed on the bench that reflects pressure interactions between lungs and heart during CPR. A circulation circuit is included, with St Jude Medical prosthetic valves. Arterial pressures were measured as developed with each of the 3 compared modalities of CPR: standard (STD), ITD, and the proposed synchronized airway valve (SAV) CPR.
Results: SAV mean arterial presures were 38 mmHg, while STD and ITD pressures were 26 and 31 mmHg, respectively.
Conclusions: On a bench model, using synchronized airway valve CPR enhanced mean arterial blood pressure beyond standard and ITD.
- © 2010 by American Heart Association, Inc.