Pocket sized ultrasound devices (PUDs) have potential to improve global health care delivery due to their potential role in areas with limited resources. Although theoretically they have much promise, their use has been limited due to a lack of imaging protocol and trained users.
This particular study, titled — “Feasibility of remote real-time guidance of a cardiac examination performed by novices using a pocket-sized ultrasound device” looked at the cardiac limited ultrasound exam (CLUE) to screen for left ventricular (LV) systolic dysfunction, left atrial (LA) enlargement, ultrasound lung comets, and elevated central venous pressure (CVP).
Previous studies have shown that CLUE not only provides diagnostic and prognostic data, but also confers the potential of wireless transmission of data (unavailable for traditional bedside cardiac exams).
To determine the feasibility of utilizing low-cost smartphone based applications that allow wireless video conferencing to guide novice users in using CLUE.
A novice with limited training can perform CLUE using PUD when wirelessly guided by an expert (using FaceTime — explained in the Methods section below). This method can increase the use of PUD and help in emergency settings and medical triage.
Commentary and Implication to mHealth:
CLUE screens for signs associated with potentially life-threatening diagnoses. For example, LV systolic dysfunction detected by CLUE occurs acutely in myocardial infarctions, septic shock, and acute heart failure. Based on the results of this study, Facetime technology can be used with PUDs to perform CLUE in emergency settings when cardiologists are not on the scene.
Not only would these signs evaluate acute cardiac processes, but the eCVP for example, can help differentiate between different types of shock. Using tools that allow healthcare providers to communicate with experts and consult specialists can save valuable time and minimize morbidity and mortality and lead to better patient outcomes. This was a relatively small study and needs further and larger studies that investigate using other signs that can be present in emergency situations. Also, as this has implied use as a screening tool in emergency scenarios, one would hope the technology should achieve higher sensitivity (study’s sensitivity was 0.67).
Three trainees in San Diego, California with less than one-hour device orientation and no previous ultrasound experience performed CLUE using a PUD ( either the Vscan, GE Healthcare, or the P10, Siemens Healthcare) attached to an iPhone 4 or iPod using a mount. The mount enabled the iPhone/iPod’s front facing VGA camera to be facing the PUD display screen using the Apple’s Facetime — data from subjects’ ultrasound was transmitted to an off-site cardiologist’s iPod. The off-site cardiologist then assessed the quality of the images and trainee’s image acquiring technique and provided remote audiovisual guidance and interpretation of CLUE signs to the trainees.
The accuracy and quality of the PUD transmitted images was then compared to the gold standard echocardiograms performed by a registered sonographer. Values such as diagnostic sensitivity, specificity, accuracy, positive and negative predictive value were derived by using the standard echocardiogram for reference.
In all 27 subjects, there was successful transmission of Ultrasound images and guidance from offsite physicians. 2/27 transmissions were dropped and re-initiated. Remotely-guided novice image yielded adequate CLUE views with 90% success versus sonographer imaging which achieved 96% success(p <0.05). Compared to the gold-standard echo thresholds, CLUE had a combined sensitivity of 0.67, specificity of 0.96, and an accuracy of 0.90 .
Article Name: Feasibility of remote real-time guidance of a cardiac examination performed by novices using a pocket-sized ultrasound device.
Authors: Mai TV, Ahn DT, Phillips CT, Agan DL, Kimura BJ.
Journal Published: Emerg Med Int.
Date Published: August 20, 2013
Citation: Emerg Med Int. 2013;2013:627230. doi: 10.1155/2013/627230. Epub 2013 Aug 20.