Paramedic assessment of carotid artery pulsation using pre-recorded ultrasound videos: a comparative analysis of three ultrasound modes

TL;DR

This study shows that paramedics with minimal training can accurately detect carotid artery pulsation using ultrasound, which could replace manual pulse checks during resuscitation.

Contribution

The study demonstrates that paramedics can reliably detect carotid artery pulsation via ultrasound, particularly using M-mode and Color Doppler.

Findings

M-mode and Color Doppler ultrasound achieved over 95% accuracy in identifying carotid artery pulsation.

B-mode ultrasound had lower accuracy (78%) for detecting pulsation compared to other modes.

Paramedics showed high accuracy in identifying both presence and absence of pulsation in controlled settings.

Abstract

This cross-sectional study aimed to determine whether paramedics with limited or no prior ultrasound experience can consistently identify the presence or absence of common carotid artery (CCA) pulsation, as a potential alternative to manual pulse checks during cardiopulmonary resuscitation.

Following a six-minute instructional video, paramedics assessed short pre-recorded ultrasound videos of the CCA acquired in B-mode, M−mode, and Color Doppler. Each of the 93 participants viewed 24 randomized 10-second videos and classified each as showing pulsation or no pulsation. To replicate clinical conditions where manual pulse checks may fail − such as post-resuscitation − videos were recorded during two distinct phases of cardiac surgery: (1) under controlled hypotension and (2) during complete circulatory standstill following aortic clamping.

A total of 2232 assessments were analyzed. M−mode: Participants correctly identified CCA pulsation in 95 % (265/279) of assessments. In videos without CCA pulsation, the correct classification of ‘no pulsation present’ was achieved in 97 % (270/279). B-mode: The presence of CCA pulsation was correctly identified in 78 % (218/279), whereas in 22 % (61/279) of cases, participants incorrectly categorized the video as ‘no pulsation present’ despite pulsation being present. Conversely, the absence of CCA pulsation was accurately detected in 98 % (635/651) of cases. Color Doppler: CCA pulsation was correctly identified in 99 % (551/558) of assessments. Similarly, in videos without CCA pulsation, participants correctly classified 96 % (185/186) as ‘no pulsation present’.

Paramedics demonstrated a high level of diagnostic accuracy in identifying both the presence and absence of CCA pulsation using two-dimensional (2D) ultrasound across multiple imaging modes in a controlled study setting. The findings suggest that the combination of Color Doppler and, in particular, M−mode appears to be the most suitable approach for identifying CCA pulsation via ultrasound.

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