Intraventricular pressure and volume during conventional and automated head-up CPR

Area of Science:

• Cardiology
• Emergency Medicine
• Physiology

Background:

• Conventional cardiopulmonary resuscitation (CPR) has limitations in maintaining adequate blood flow.
• Active compression-decompression (ACD) CPR with an impedance threshold device (ITD) and automated head and thorax elevation (AHUP-CPR) shows promise in animal models.
• AHUP-CPR has demonstrated increased perfusion pressures and blood flow in preclinical studies.

Purpose of the Study:

• To test the hypothesis that AHUP-CPR yields higher cardiac stroke volume (SV) compared to conventional (C) CPR or ACD + ITD.
• To evaluate the impact of AHUP-CPR on hemodynamic parameters in a porcine cardiac arrest model.

Main Methods:

• A porcine model of cardiac arrest (n=14) was utilized.
• Hemodynamic measurements, including biventricular pressure-volume loops, were continuously recorded.
• Sequential application of C-CPR, ACD + ITD, and AHUP-CPR was performed, followed by statistical analysis.

Main Results:

• AHUP-CPR significantly increased right and left ventricular stroke volumes compared to C-CPR.
• Right ventricular SV increased from ~48% to ~90% of baseline with AHUP-CPR, and left ventricular SV increased from ~35% to ~80% of baseline.
• Progressive and significant increases in perfusion pressures, end-tidal CO2, and cerebral oximetry were observed with AHUP-CPR.

Conclusions:

• AHUP-CPR effectively overcomes the limitation of reduced cardiac stroke volume inherent in conventional CPR.
• The enhanced forward flow achieved with AHUP-CPR may contribute to improved clinical outcomes.
• These findings support the potential benefit of early implementation of AHUP-CPR in cardiac arrest management.