Why Mechanical CPR?
High-quality chest compressions are the foundation of cardiac arrest resuscitation. However, maintaining consistent compression depth, rate, and full recoil is physically demanding and degrades quickly, even for well-trained providers. Mechanical CPR devices deliver consistent, uninterrupted compressions that do not fatigue over time, making them valuable tools in specific prehospital scenarios.
Common Mechanical CPR Devices
LUCAS (Lund University Cardiac Assist System)
The LUCAS device uses a suction cup attached to the patient's sternum and a piston mechanism to deliver compressions at a consistent depth of approximately 5 to 6 centimeters at 102 compressions per minute. It provides active decompression (pulling the chest back up), which may improve venous return. The LUCAS device is battery-powered and can operate continuously without human intervention once applied.
AutoPulse
The AutoPulse uses a load-distributing band that wraps around the patient's torso and squeezes to deliver compressions. Instead of a single piston point, the band distributes force across the chest, potentially reducing rib fractures while maintaining effective compression. The AutoPulse automatically adjusts to the patient's chest size during its sizing sequence.
When to Use Mechanical CPR
Mechanical CPR devices are indicated in situations where manual compressions are difficult or impossible to sustain:
- Prolonged resuscitations where provider fatigue degrades compression quality
- Transport in moving ambulances where consistent manual compressions are challenging
- During procedures that require interruption of manual CPR (such as percutaneous coronary intervention in the cath lab)
- When limited personnel are available for resuscitation
- Hypothermic cardiac arrest requiring extended resuscitation
Limitations and Considerations
Mechanical CPR devices should not delay the start of manual compressions. Apply the device during a planned pause in CPR (such as during rhythm analysis) and keep interruptions to a minimum. The devices do not work on all patients: pediatric patients, patients with extreme body habitus, and patients with chest deformities may not be appropriate candidates. Current evidence shows that mechanical CPR devices produce outcomes equivalent to high-quality manual compressions, not superior. They are tools that maintain quality when manual compression quality would otherwise degrade.