A wearable carotid Doppler tracks changes in the descending aorta and stroke volume induced by end-inspiratory and end-expiratory occlusion: A pilot study

Abstract

Background and Aims: To test the feasibility of a novel, wearable carotid Doppler ultrasound to track changes in cardiac output induced by end-inspiratory and end-expiratory occlusion tests. Methods: We observed the pattern of Doppler change of the common carotid artery during a simulated end-inspiratory and expiratory occlusion test (sEIOT/sEEOT) in 10, nonventilated, healthy subjects. Simultaneously, we measured the Doppler signal of the descending aorta using duplex ultrasound (Xario, Toshiba Medical Systems) and stroke volume (SV) using noninvasive pulse contour analysis (Clearsight, Edwards Lifesciences, Irvine, California). Results: During sEIOT, SV, maximum velocity time integral (VTI) of the descending aorta, and common carotid fell by 25.7% (P =.0131), 26.1% (P