Is it appropriate to set the Impella (Intra-Aortic Balloon Pump) to P2 during cardiac arrest?

Impella Management During Cardiac Arrest

During cardiac arrest, the Impella device should be set to maximum power (P8) to provide the highest possible mechanical circulatory support for maintaining vital organ perfusion. 1

Rationale for Maximum Support Setting

• The Impella is a percutaneous ventricular assist device that propels blood from the left ventricle into systemic circulation, providing critical circulatory support during cardiac arrest 1
• Setting the Impella to maximum flow (P8) during cardiac arrest is essential to maintain vital organ perfusion while addressing the underlying cause of arrest 1
• Lower power settings (such as P2) provide insufficient support during cardiac arrest when complete circulatory collapse has occurred 1

Integration with ACLS Protocols

• High-quality chest compressions should continue at 100-120/min with 5-6 cm depth while Impella support is being maximized 1
• Chest compression fraction should be maintained at least 60% to ensure adequate perfusion 1
• Peripheral VA-ECMO increases LV afterload, which can negatively impact cardiac recovery, making appropriate Impella settings crucial 2

Clinical Evidence Supporting Maximum Support

• Early initiation of mechanical circulatory support with Impella at maximum settings has been associated with improved hospital and 6-month survival in patients with post-cardiac arrest cardiogenic shock 3
• In a multicenter registry, Impella CP insertion during ongoing CPR for cardiac arrest was associated with a 37.1% rate of 30-day survival without neurological impairment 4
• Factors associated with survival include younger age (<75 years) and shorter time from arrest to CPR (≤5 minutes) 4

Special Considerations

• Anticoagulation is required with Impella devices to prevent pump thrombosis, typically with an initial unfractionated heparin bolus of 100 U/kg (up to 5000 U maximum) 5
• Echocardiographic guidance is recommended for optimal positioning of the Impella device during placement 1
• Vascular complications are more common with Impella compared to IABP (9.8% vs 3.8%), requiring careful attention to access site management 5

Management Algorithm

1. Immediately set Impella to P8 (maximum support) during cardiac arrest 1
2. Continue high-quality CPR with minimal interruptions 1
3. Address reversible causes of arrest while maintaining maximum Impella support 1
4. If no return of spontaneous circulation within 30 minutes despite maximum support, consider escalation to VA-ECMO if available 1
5. For patients with LV distension on VA-ECMO, maintain Impella at maximum settings to provide LV venting 2

Potential Pitfalls

• Using lower power settings (such as P2) during cardiac arrest provides inadequate circulatory support 1
• Failure to maintain anticoagulation may lead to pump thrombosis 5
• In patients with hypoxemic respiratory failure, Impella use is contraindicated as it may exacerbate hypoxemic cerebral perfusion 2