# Feasibility and Confidence in Carotid Spectral Doppler for Pulse Detection: Training Outcomes Among Emergency Medicine Residents

## TL;DR

This study shows that emergency medicine residents can be quickly trained to use carotid spectral Doppler to detect pulses during CPR, with high success and confidence rates.

## Contribution

The study introduces a feasible training method for using carotid spectral Doppler for pulse detection by novice ultrasound users.

## Key findings

- All 38 residents successfully obtained a spectral Doppler waveform from the common carotid artery.
- 92% of residents performed the task without instructor assistance, and 97% felt confident using the technique on real patients.
- The average time to obtain a waveform was 23 seconds, with 32% completing it within 15 seconds.

## Abstract

Introduction

Carotid ultrasound has demonstrated utility in identifying the presence of a pulse, particularly in cardiac arrest. Despite this evidence, there is currently no existing literature that focuses on the training of physicians in this modality for the purpose of pulse detection. The primary objective of this study is to demonstrate that novice ultrasound users with varying levels of training can be taught a simple and repeatable method for identifying flow in the common carotid artery (CCA) using a combination of B-mode ultrasound and spectral Doppler. The secondary objective is to evaluate the confidence of emergency medicine (EM) residents with varying levels of ultrasound experience in accurately identifying the carotid pulse using spectral Doppler.

Methods

This is a cross-sectional study, using a convenience sample of emergency medicine (EM) residents. Residents with varying levels of ultrasound experience received training on obtaining CCA ultrasound images and spectral Doppler. Subjects were then asked to image the common carotid artery and obtain a spectral Doppler waveform on a standardized patient. Expert sonologists observed participants’ imaging in real time and recorded their performance. Participants completed a post-questionnaire detailing the number of previous ultrasound examinations they had performed and their comfort level with the carotid ultrasound technique.

Results

Thirty-eight residents participated in the study. The residents were able to obtain a spectral Doppler waveform from the CCA in 38 (100%) of cases, and 35 (92%) residents were able to perform this task without any assistance from the instructor. The average time to obtain a waveform was 23 seconds. Twelve (32%) residents were able to obtain a pulse within 15 seconds. After the training session, 37 (97%) residents felt comfortable identifying arterial flow in the CCA using spectral Doppler and would feel comfortable using this technique on an actual patient receiving cardiopulmonary resuscitation (CPR).

Conclusion

Spectral Doppler of the CCA may be a reasonable alternative for identifying return of spontaneous circulation (ROSC) during pulse check of patients receiving CPR. All residents were able to identify pulses using spectral Doppler, following a brief lecture, instructional video, and hands-on training session.