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. 2022 Jan 10;15(1):7.
doi: 10.1186/s13104-021-05896-y.

Carotid artery velocity time integral and corrected flow time measured by a wearable Doppler ultrasound detect stroke volume rise from simulated hemorrhage to transfusion

Jon-Émile S Kenny  1   2 , Igor Barjaktarevic  3 , David C Mackenzie  4   5 , Mai Elfarnawany  6 , Zhen Yang  6 , Andrew M Eibl  7   6 , Joseph K Eibl  7   6   8 , Chul-Ho Kim  9 , Bruce D Johnson  9
Affiliations

Carotid artery velocity time integral and corrected flow time measured by a wearable Doppler ultrasound detect stroke volume rise from simulated hemorrhage to transfusion

Jon-Émile S Kenny et al. BMC Res Notes. .

Abstract

Objective: Doppler ultrasonography of the common carotid artery is used to infer stroke volume change and a wearable Doppler ultrasound has been designed to improve this workflow. Previously, in a human model of hemorrhage and resuscitation comprising approximately 50,000 cardiac cycles, we found a strong, linear correlation between changing stroke volume, and measures from the carotid Doppler signal, however, optimal Doppler thresholds for detecting a 10% stroke volume change were not reported. In this Research Note, we present these thresholds, their sensitivities, specificities and areas under their receiver operator curves (AUROC).

Results: Augmentation of carotid artery maximum velocity time integral and corrected flowtime by 18% and 4%, respectively, accurately captured 10% stroke volume rise. The sensitivity and specificity for these thresholds were identical at 89% and 100%. These data are similar to previous investigations in healthy volunteers monitored by the wearable ultrasound.

Keywords: Carotid Doppler; Corrected flow time; Stroke volume; Velocity time integral.

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Conflict of interest statement

JESK, ME, ZY, AME, JKE are employees of Flosonics Medical, a start-up building the wearable ultrasound, IB reports consulting fees for GE Healthcare, DCM, CHK and BDJ report no conflicts.

Figures

Fig. 1
Fig. 1
Picture of wireless, wearable Doppler ultrasound device
Fig. 2
Fig. 2
Hemodynamic data captured during lower body negative pressure (LBNP) and release. Measures from A–D are synchronously captured. Each faint line represents a single protocol, while the emboldened line represents the average of all protocols. A Stroke volume (SV) percent change during progressively severe LBNP (i.e., hemorrhage model) and release of LBNP (i.e., rapid transfusion model). B Mean arterial pressure (MAP) percent change. C velocity time integral (VTI) from the wearable Doppler percent change. D corrected flow time (ccFT) percent change. E The optimal carotid artery maximum VTI threshold for distinguishing ≥  + 10% SV∆. Each data point represents a 10-s average. Prior to subsampling, there were 3596 data points categorized as <  + 10% SV∆ and 598 data points categorized as ≥  + 10% SV∆. The data categorized as <  + 10% SV∆ were randomly subsampled, iteratively 1000 times, to 598 data points (see methods). The sensitivity of maximum VTI is 532/598 = 89% and specificity is 598/598 = 100%. F The optimal ccFT threshold for distinguishing + 10% SV∆. Each data point represents a 10-s average. The sensitivity is 532/598 = 89% and specificity is 598/598 = 100%
See this image and copyright information in PMC

References

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