Relationship between Femoral Arterial Peak Systolic Velocity and Arterial Blood Pressure during Compressions in Cardiac Arrest

Despite decades of focused cardiopulmonary resuscitative (CPR) research and quality systems improvement studies, survival rates from patients who suffer from cardiac arrest remain low. Current CPR targets stress the importance of quality chest compressions.. One marker of CPR quality that has yet to be investigated is the utility of femoral arterial peak systolic velocity (PSV) as a marker of the adequacy of compressions. The objective of this study was to determine if there was a correlation between femoral arterial PSV and systolic blood pressure tracings on an arterial line during chest compressions.

This was a retrospective study carried out on a prospectively collected convenience sample of adult emergency department cardiac arrest patients in a quaternary care center. Patients were enrolled if they had a femoral arterial line in place, older than 18 years of age and either an ultrasound or critical care trained faculty member was available to record the femoral PSV. Once a patient was eligible, study personnel would place a linear probe in transverse orientation over the femoral artery and record the spectral Doppler tracing during active chest compressions.Additional study personnel would retrospectively review the arrest video to document the peak femoral arterial blood pressure that corresponded to the femoral arterial PSV on Doppler.

A total of 8 patients were included in this study with 28 pairs of PSV and SBP data analyzed. The median highest PSV during chest compressions was 70 (IQR 40.5-85.0) and the median highest SBP during chest compressions was 84 (IQR 67.0-117.5). We found a significant correlation between highest PSV during chest compressions and highest SBP during chest compressions (r = 0.71, p < 0.001)

The results of our study suggest that the peak femoral arterial systolic velocities correlate with arterial systolic blood pressures tracings from A-lines, in cardiac arrest patients receiving compressions. Recent evidence suggests that current chest compression locations may impede cardiac output; however, making this determination requires invasive monitoring devices like transesophageal echocardiograms which are not available in many ED’s. Doppler ultrasound tracings may provide a simple and non-invasive tool to evaluate perfusion. Future large-scale trials are needed to further evaluate the potential of femoral arterial tracings.