# 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.

## Key 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.