From the Health Sciences North Research Institute (J.-É.S.K., A.M.E., J.K.E.); Northern Ontario School of Medicine (J.K.E.), Sudbury, Ontario, Canada; Flosonics Medical (J.-É.S.K., M.E, Z.Y., A.M.E., J.K.E.), Toronto, Ontario, Canada; and Human Integrative and Environmental Physiology Laboratory, Department of Cardiovascular Diseases (C.-H.K. B.D.J.), Mayo Clinic, Rochester, MN.
J Trauma Acute Care Surg. 2022 Aug 1;93(2S Suppl 1):S35-S40. doi: 10.1097/TA.0000000000003698. Epub 2022 May 21.
We have developed a wireless, wearable Doppler ultrasound system that continuously measures the common carotid artery Doppler pulse. A novel measure from this device, the Doppler shock index, accurately detected moderate-to-severe central blood volume loss in a human hemorrhage model generated by lower body negative pressure. In this analysis, we tested whether the wearable Doppler could identify only mild-to-moderate central blood volume loss.
Eleven healthy volunteers were recruited and studied in a physiology laboratory at the Mayo Clinic. Each participant underwent a lower body negative protocol in duplicate. Carotid Doppler measures including Doppler shock indices were compared with blood pressure and the shock index for their ability to detect both 10% and 20% reductions in stroke volume.
All carotid Doppler measures were better able to detect diminishing stroke volume than either systolic or mean arterial pressure. Falling carotid artery corrected flow time and rising heart rate/corrected flow time (DSI FTc ) were the most sensitive measures for detecting 10% and 20% stroke volume reductions, respectively. The area under the receiver operator curves (AUROCs) for all shock indices was at least 0.86; however, the denominators of the two Doppler shock indices (i.e., the corrected flow time and velocity time integral) had AUROCs ranging between 0.81 and 0.9, while the denominator of the traditional shock index (i.e., systolic blood pressure) had AUROCs between 0.54 and 0.7.
The wearable Doppler ultrasound was able to continuously measure the common carotid artery Doppler pulse. Carotid Doppler measures were highly sensitive at detecting both 10% and 20% stroke volume reduction. All shock indices performed well in their diagnostic ability to measure mild-to-moderate central volume loss, although the denominators of both Doppler shock indices individually outperformed the denominator of the traditional shock index.
Diagnostic test or criteria; Level III.
我们开发了一种无线可穿戴式多普勒超声系统，可连续测量颈总动脉多普勒脉搏。该设备的一项新指标——多普勒冲击指数，可准确检测下体负压致人体中度至重度中心血容量丢失。在这项分析中，我们测试了可穿戴式多普勒是否仅能识别轻度至中度中心血容量丢失。
11 名健康志愿者在梅奥诊所的生理学实验室中进行了研究。每位参与者均进行了两次下体负压方案。比较颈动脉多普勒测量指标（包括多普勒冲击指数）与血压和冲击指数，以评估其检测心排量降低 10%和 20%的能力。
所有颈动脉多普勒测量指标均比收缩压或平均动脉压更能检测到心排量减少。颈动脉校正流量时间减少和心率/校正流量时间升高（DSI FTc）分别是检测心排量减少 10%和 20%的最敏感指标。所有冲击指数的接收者操作特征曲线（AUROCs）均至少为 0.86；然而，两个多普勒冲击指数的分母（即校正流量时间和速度时间积分）的 AUROCs 在 0.81 到 0.9 之间，而传统冲击指数（即收缩压）的分母的 AUROCs 在 0.54 到 0.7 之间。
可穿戴式多普勒超声能够连续测量颈总动脉多普勒脉搏。颈动脉多普勒测量对检测心排量降低 10%和 20%非常敏感。所有冲击指数在检测轻度至中度中心容量丢失方面的诊断能力都很好，尽管两个多普勒冲击指数的分母单独优于传统冲击指数的分母。
诊断测试或标准；三级。
