Continuous measurement of pulse wave velocity during general anaesthesia using carotid and femoral Doppler

Objective Pulse wave velocity (PWV), a measure of arterial stiffness, varies with mean arterial pressure (MAP). As general anesthesia (GA) causes significant variations in MAP, we proposed to study the feasibility of measuring PWV under GA and to investigate its relationship with MAP. Methods From December 2022 to February 2023, continuous carotid and femoral Doppler monitoring was performed on patients scheduled for surgery with GA, to collect PWV data at awakening (PWV _AW ) and during GA (PWV _GA ). The study investigated PWV's response to MAP fluctuations using the α-angle, a dynamic stiffness parameter. We evaluated PWV and α-angle efficacy in discriminating between low (CVR-) and high (CVR+) cardiovascular risk patients. Results Among 43 patients, 41 (95%) had successful PWV measurements. PWV _AW was significantly higher than PWV _GA (8.1 vs 7.4 m.s ^-1 , p < 0.0001). This difference vanished after matching MAP levels. A strong correlation was found between PWV _AW and PWV _GA (r = 0.88, and r = 0.97 at the same MAP levels). PWV _GA , α-angle and their product (α x PWV _GA ) were significantly higher in CVR + patients (8.1 vs 6.9 m.s ^-1 , p < 0.01; 2.6 vs 1.3 degrees, p < 0.001; 21.8 vs 8.1 degrees.m.s ^-1 , p < 0.001, respectively), with AUC values indicating good predictive capabilities for cardiovascular risk (PWV _GA : AUC [95%CI] = 0.80 [0.65–0.95]; α-angle: 0.83 [0.69–0.96]; product: 0.86 [0.74–0.97]). Conclusion Measuring PWV using carotid and femoral Doppler under GA is viable and can discriminate between varying levels of cardiovascular risk. The α-angle offers a promising approach to refining the assessment of arterial stiffness.