Continuous measurement of carotid-femoral pulse wave velocity (PWVcf.) during general anaesthesia using Doppler: a preliminary study.

This study explores the feasibility of continuous pulse wave velocity (PWV) monitoring during general anaesthesia (GA), particularly in response to blood pressure fluctuations. Our aim is to evaluate whether dynamic PWV can provide new insight to detect cardiovascular risks. 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. 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]). Measurement of PWV under GA using carotid and femoral Doppler is a feasible method to continuously assess arterial stiffness under general anaesthesia. Further studies are required to validate the α-angle parameter in different physiological conditions.