Study objective: To develop an automatic mechanical device capable of performing active compression–decompression (ACD) CPR in laboratory animals.

Design: A swine model was used to study standard and ACD CPR. One-minute periods of standard mechanical chest compressions were alternated with mechanical ACD CPR. Setting: University hospital laboratory. Interventions: A commercially available device that provided standard chest compressions only was modified to deliver ACD CPR. Results: The absolute difference in intrapleural pressure and tidal volume almost doubled during ACD CPR compared with that with standard CPR. Conclusion: The presence of a greater negative change in intrapleural pressure confirmed that active decompression of the chest had occurred and that the device was capable of performing ACD CPR. The device provides consistent rate, depth, force, and duty cycle. [Wenzel V, Fuerst RS, Idris AH, Banner MJ, Rush WJ, Orban DJ: Automatic mechanical device to standardize active compression–decompression CPR. Ann Emerg Med March 1995;25:386-389.]