Abstract 10014: Guiding Novices to Obtain a Cardiac Limited Ultrasound Exam with Ultrasound Stethoscopes Using Wireless Transmission: Feasibility of Low-Cost Remote Imaging and Training
Background: Although battery-operated ultrasound stethoscopes can augment the physical exam, their potential to improve global healthcare delivery has been limited by the lack of a suitable imaging protocol and trained users. Therefore, we investigated the feasibility of performing a brief, evidence-based cardiac limited ultrasound exam (CLUE) through wireless guidance of novice users.
Methods: Three briefly-oriented trainees (medical student, intern, and pharmacy resident) applied pocket-sized ultrasound devices (Vscan, GE Healthcare; P10, Siemens Healthcare) on 27 subjects (22 outpatients, 5 controls) while directed by an off-site cardiologist, in order to obtain a 4-view CLUE (parasternal LV long-axis, bilateral apical lung and subcostal IVC) shown to screen for LV systolic dysfunction (LVD), LA enlargement (LAE), interstitial lung edema (ILE), and elevated CVP (eCVP). Remote audio guidance and subjective interpretation of CLUE signs were performed in real-time using off-the-shelf technologies (iPod/FaceTime, Apple Inc.), that were attached to the stethoscopes and transmitted data wirelessly through the Internet. Screening accuracy and technical quality (scale 1-4) of transmitted CLUE images were compared to on-site, gold-standard echo thresholds of E-point septal separation>1.0cm, >3 lung comets/field, LA diameter>4.0 cm and IVC collapse <50%.
Results: Guided-novice vs. sonographer imaging yielded technically-adequate CLUE views (score >3) in 122/135 (90%) vs. 130/135 (96%) (p<0.05). Two calls (7%) were dropped and re-initiated. CLUE had a combined SN, SP, and ACC of 0.67, 0.96, and 0.90 for echo thresholds. Technical adequacy (%) and CLUE accuracy for each abnormality (n) were: LVD (85%, 0.93, n=5), LAE (89%, 0.74, n=16), ILE (100%, 0.94, n=5), and eCVP (78%, 0.96, n=1).
Conclusion: A novice can perform a specific 4-view CLUE appropriate for ultrasound stethoscopes when guided “live” by an expert using wireless transmission. This method combines a simplified imaging protocol with inexpensive technologies and could facilitate the use of ultrasound for off-site bedside medical decision-making and training.
- © 2011 by American Heart Association, Inc.