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Can emergency physicians perform common carotid Doppler flow measurements to assess volume responsiveness?

Stolz LA, Mosier JM, Gross AM, Douglas MJ, Blaivas M, Adhikari S - West J Emerg Med (2015)

Bottom Line: Participants successfully completed all performance measures greater than 75% of the time, with the exception of obtaining measurements during systole, which was completed in 65% of examinations.When assessed at performing this examination, they completed several performance measures with greater than 75% success.No differences were found between novice and experienced groups.

View Article: PubMed Central - PubMed

Affiliation: University of Arizona, Department of Emergency Medicine, Tucson, Arizona.

ABSTRACT

Introduction: Common carotid flow measurements may be clinically useful to determine volume responsiveness. The objective of this study was to assess the ability of emergency physicians (EP) to obtain sonographic images and measurements of the common carotid artery velocity time integral (VTi) for potential use in assessing volume responsiveness in the clinical setting.

Methods: In this prospective observational study, we showed a five-minute instructional video demonstrating a technique to obtain common carotid ultrasound images and measure the common carotid VTi to emergency medicine (EM) residents. Participants were then asked to image the common carotid artery and obtain VTi measurements. Expert sonographers observed participants imaging in real time and recorded their performance on nine performance measures. An expert sonographer graded image quality. Participants were timed and answered questions regarding ease of examination and their confidence in obtaining the images.

Results: A total of 30 EM residents participated in this study and each performed the examination twice. Average time required to complete one examination was 2.9 minutes (95% CI [2.4-3.4 min]). Participants successfully completed all performance measures greater than 75% of the time, with the exception of obtaining measurements during systole, which was completed in 65% of examinations. Median resident overall confidence in accurately performing carotid VTi measurements was 3 (on a scale of 1 [not confident] to 5 [confident]).

Conclusion: EM residents at our institution learned the technique for obtaining common carotid artery Doppler flow measurements after viewing a brief instructional video. When assessed at performing this examination, they completed several performance measures with greater than 75% success. No differences were found between novice and experienced groups.

No MeSH data available.


Ultrasound image of common carotid diameter measurement obtained within 0.5 cm of the carotid bulb and measured intima to intima.
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Related In: Results  -  Collection

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f1-wjem-16-255: Ultrasound image of common carotid diameter measurement obtained within 0.5 cm of the carotid bulb and measured intima to intima.

Mentions: We created a five-minute instructional video demonstrating a technique to obtain common carotid ultrasound images and measure the common carotid VTi based on previously published methods.12 The published technique involves obtaining antero-posterior measurements of the common carotid artery diameter in systole within approximately 0.5cm of the common carotid bulb in the long axis with a 12-7 MHz broadband linear array transducer (Figure 1, Video 1). The VTi is then determined through digitalized Doppler spectral envelopes with the sample obtained at the location that the diameter was taken. The Doppler gate is placed in the middle of the artery with a 45- to 60-degree angle of insonation (Figure 2, Video 2). We sent the instructional video by email to all potential participants to review, and it was available for them to review again prior to their performance of the examination. Images were obtained by each participant on two healthy volunteers using a Mindray M7 (Shenzhen, China). Two expert sonographers observed participants performing the technique in realtime. They recorded each participant’s performance on nine performance measures as a dichotomous variable, either as successfully completed or not. Participants filled out a questionnaire detailing the number of previous ultrasound examinations they had performed, their comfort level with the technique and their preference for the brief video as a learning method versus others. An additional expert sonographer who was blinded to the study hypothesis reviewed the images and assessed all images for Doppler sample volume placement, accuracy of measurement of common carotid artery diameter and image quality using a scale of 1 (poor image quality) - 5 (excellent image quality). All expert sonographers had performed greater than 1000 POC ultrasound examinations before the study period.


Can emergency physicians perform common carotid Doppler flow measurements to assess volume responsiveness?

Stolz LA, Mosier JM, Gross AM, Douglas MJ, Blaivas M, Adhikari S - West J Emerg Med (2015)

Ultrasound image of common carotid diameter measurement obtained within 0.5 cm of the carotid bulb and measured intima to intima.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4380375&req=5

f1-wjem-16-255: Ultrasound image of common carotid diameter measurement obtained within 0.5 cm of the carotid bulb and measured intima to intima.
Mentions: We created a five-minute instructional video demonstrating a technique to obtain common carotid ultrasound images and measure the common carotid VTi based on previously published methods.12 The published technique involves obtaining antero-posterior measurements of the common carotid artery diameter in systole within approximately 0.5cm of the common carotid bulb in the long axis with a 12-7 MHz broadband linear array transducer (Figure 1, Video 1). The VTi is then determined through digitalized Doppler spectral envelopes with the sample obtained at the location that the diameter was taken. The Doppler gate is placed in the middle of the artery with a 45- to 60-degree angle of insonation (Figure 2, Video 2). We sent the instructional video by email to all potential participants to review, and it was available for them to review again prior to their performance of the examination. Images were obtained by each participant on two healthy volunteers using a Mindray M7 (Shenzhen, China). Two expert sonographers observed participants performing the technique in realtime. They recorded each participant’s performance on nine performance measures as a dichotomous variable, either as successfully completed or not. Participants filled out a questionnaire detailing the number of previous ultrasound examinations they had performed, their comfort level with the technique and their preference for the brief video as a learning method versus others. An additional expert sonographer who was blinded to the study hypothesis reviewed the images and assessed all images for Doppler sample volume placement, accuracy of measurement of common carotid artery diameter and image quality using a scale of 1 (poor image quality) - 5 (excellent image quality). All expert sonographers had performed greater than 1000 POC ultrasound examinations before the study period.

Bottom Line: Participants successfully completed all performance measures greater than 75% of the time, with the exception of obtaining measurements during systole, which was completed in 65% of examinations.When assessed at performing this examination, they completed several performance measures with greater than 75% success.No differences were found between novice and experienced groups.

View Article: PubMed Central - PubMed

Affiliation: University of Arizona, Department of Emergency Medicine, Tucson, Arizona.

ABSTRACT

Introduction: Common carotid flow measurements may be clinically useful to determine volume responsiveness. The objective of this study was to assess the ability of emergency physicians (EP) to obtain sonographic images and measurements of the common carotid artery velocity time integral (VTi) for potential use in assessing volume responsiveness in the clinical setting.

Methods: In this prospective observational study, we showed a five-minute instructional video demonstrating a technique to obtain common carotid ultrasound images and measure the common carotid VTi to emergency medicine (EM) residents. Participants were then asked to image the common carotid artery and obtain VTi measurements. Expert sonographers observed participants imaging in real time and recorded their performance on nine performance measures. An expert sonographer graded image quality. Participants were timed and answered questions regarding ease of examination and their confidence in obtaining the images.

Results: A total of 30 EM residents participated in this study and each performed the examination twice. Average time required to complete one examination was 2.9 minutes (95% CI [2.4-3.4 min]). Participants successfully completed all performance measures greater than 75% of the time, with the exception of obtaining measurements during systole, which was completed in 65% of examinations. Median resident overall confidence in accurately performing carotid VTi measurements was 3 (on a scale of 1 [not confident] to 5 [confident]).

Conclusion: EM residents at our institution learned the technique for obtaining common carotid artery Doppler flow measurements after viewing a brief instructional video. When assessed at performing this examination, they completed several performance measures with greater than 75% success. No differences were found between novice and experienced groups.

No MeSH data available.