Handheld Ultrasound A Heartbeat Away from Ousting the Stethoscope?

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 - VScan
The Vscan is a portable and pocket-size ultrasound device that allows cardiologists to do imaging at the point of care.
Source: Scripps Health

The stethoscope appears to have a name branding issue. The word “scope” derives from the Greek word for “to look,” yet stethoscopes only let physicians listen to a patient. Handheld ultrasound technology has gained traction as a tool to improve cost-efficient care and serve as an extension to traditional physical examination. Are we entering the era of handheld ultrasound as the new stethoscope?

Ultrasound devices are now at a point where they can be kept in a physician’s pocket, yet the tiny tools still pack enough technological capability to generate high-quality images of cardiac structure and function from the patient’s bedside. There’s nothing you can learn with a stethoscope during a physical exam that you can’t with a handheld ultrasound, according to Jagat Narula, MD, PhD, director of the cardiovascular imaging program at the Icahn School of Medicine at Mount Sinai in New York City.

Narula is a passionate evangelist of the power of handheld ultrasound, and considers the technology as perhaps the most important addition to the doctor’s handbag in all of medical history. A strong endorsement, but considering it may be on the cusp of replacing the traditional stethoscope—a tool used for nearly 200 years—the declaration may not be hyperbole.

“We can use [handheld ultrasound] as a physical exam device and it will improve sensitivity,” says Narula. “It will allow us to reduce referrals to imaging.”

What the research says

While the number of studies on the effectiveness of handheld ultrasound as a tool for spotting cardiac abnormalities is limited, the results so far have been promising. A decade ago, an early study of handheld ultrasound found that first-year medical students with just 18 hours of ultrasound training could outperform the physical exam findings of board-certified cardiologists. The ultrasound-equipped students were able to identify 75 percent of the cardiac abnormalities present in the study population, compared with 49 percent identified by cardiologists (Am J Cardiol 2005;96:1002-1006).

More recent studies have shown similarly promising results for the technology. Last year, a study from Sanjiv Kaul, MD, head of the Division of Cardiovascular Medicine at Oregon Health & Science University in Portland, and colleagues sought to test both the accuracy of handheld ultrasound vs. traditional physical examination and also the impact of the devices on downstream testing and costs (J Am Coll Cardiol Img 2014;7:983–990).

A total of 250 patients were included in the study, and all had been referred for a standard echocardiogram for common indications such as murmur, stroke, cardiac function or arrhythmia. Patients underwent examination using a handheld ultrasound and also a physical exam from separate cardiologists.

“These were all trained cardiologists, academic cardiologists, who did the physical exam on patients. That’s as good as it can get,” says Kaul. “They were no match for the handheld ultrasound.”

Of the 142 abnormal findings identified on the standard echocardiogram, handheld ultrasound was able to correctly flag 82 percent, while physical exam identified only 47 percent. Handheld ultrasound was superior to physical exam for both normal and abnormal cardiac function, and it was better able to identify substantial valve disease (71 percent vs. 31 percent) and miscellaneous findings (47 percent vs. 3 percent) than physical exam.

Kaul notes that handheld ultrasound’s impact on costs as assessed by the study could be as significant as the findings on accuracy. Of the 108 patients without any abnormalities on standard echocardiography, 82 percent were referred to further testing on the basis of physical exam, while only 56 percent were referred for additional tests after undergoing examination with handheld ultrasound.

Kaul and colleagues took these referral rates and used cost modeling to show that handheld ultrasound had an average overall cost of $644.43, once additional testing was factored in, compared with $707.44 for physical exam, yielding a savings of $63.01 per patient when handheld ultrasound was used.

“In this era of Obamacare and [a focus on healthcare costs], if we can be more efficient in our patient management starting from examining them to deciding whether they need any further tests, that would be a big boost. It could save millions of dollars,” says Kaul.

Back to school

While also being bullish on the prospects of handheld ultrasound, Scott D. Solomon, MD, director of noninvasive cardiology at Brigham and Women’s Hospital in Boston, notes that cost studies are fraught with challenges that mean the economic argument for handheld ultrasound is far from settled, at least for now. For example, with a well-trained user, handheld ultrasound could save money once the technology becomes more established, but in the short-term there may be an impulse to refer patients to additional testing for miscellaneous findings that wouldn’t have been apparent to a physician armed only with a stethoscope.

“You are going to find things you weren’t going to be concerned with on a physical exam and, in part because of medico-legal conscious environment, people will think ‘I saw something on this screening test I did so I’m going to send this patient for an echocardiogram,’” says Solomon.

The key for Solomon is that the current and future generations of physicians will need to be trained to use handheld ultrasound properly. “This is a device that takes more training than a stethoscope, even though, to be honest, most people aren’t that good with a stethoscope.” Solomon suggests that the art of the physical exam has been de-emphasized with the evolution of sophisticated testing, and that physicians wound up relying on technology. True advances in accuracy and cost-savings will come when technology—in this case the handheld ultrasound—is paired with adroit examination skills.

There is every indication, however, that quality instruction can get students quickly up to speed. Fourth-year medical students with 10 days of intensive instruction showed improvement in the accuracy of cardiac bedside diagnoses using handheld ultrasound (J Am Soc Echocardiogr 2005;18:257-263). A recent study of various training regimens concluded that third-year medical students were most readily able to learn skills in performing and interpreting handheld-focused cardiac ultrasound compared with first-year students. That research also found that electronic educational modules were as effective as traditional lectures, and that hands-on sonographer training trumped simulation-based learning (J Am Soc Echocardiogr 2014;27: 302-309).

Dedication to training led to the formation of the Society for Ultrasound in Medical Education, which was developed specifically to address the need to incorporate ultrasound acquisition and interpretation skills into general medical curriculum. Severalmedical schools have taken notice and are starting to implement ultrasound training early in the curriculum, including a recent collaborative program between the Mayo Medical School in Rochester, Minn., and Mount Sinai Medical School.

“[Students examine] each other to find what is normal in their first year,” says Narula. “We hope that in the second year they will be able to see what is abnormal when they go from anatomy to pathology.”

Harvard Medical School has also introduced a pilot ultrasound curriculum integrating the technology with the teaching of the physical exam.

Beyond training, there are a number of practical issues that must be addressed before handheld ultrasound sees widespread clinical use. Solomon points out the question of documentation and whether findings should be recorded in a hospital’s picture archiving and communication system, a much more extensive record than a physician’s notes from a physical exam. There is also the matter of billing. The act of putting a stethoscope on a patient is not billed, and while the addition of handheld ultrasound does introduce some limited imaging capability, it’s doubtful that this would be seen as a formal ultrasound exam requiring separate reimbursement. If it is billed, that would start to eat into any cost savings experienced by improving accuracy over the traditional physical exam.

The devices themselves also present a cost barrier, with a price tag of around $7,000 or more. This is likely too costly to make the handheld ultrasound as ubiquitous as the stethoscope is currently, but if the price drops, market adoption may grow.

The final hurdle will be tradition. The stethoscope is one of the quintessential symbols of the medical profession, and more seasoned physicians may not be as receptive to learning a new device to integrate into their physical exam routine that has been perfected over decades. However, as training programs take hold, the next generation may “rebrand” the handheld ultrasound as the new stethoscope.

“It won’t replace echo labs or ultrasound labs by any stretch, but I also think we’re not going to be able to prevent physicians of all types from using these devices once they become inexpensive,” says Solomon.

Correct Diagnoses by Handheld Ultrasound vs. Physical Exam

Echocardiogram FindingHHU% CorrectPE%Correct% Difference
Normal LV function (n = 196)895831
Abnormal LV function (n = 54)963561
Normal RV function (n = 203)945737
Abnormal RV function (n = 47)682147
Pulmonary hypertension absent (n = 191)92893.1
Pulmonary hypertension present (n = 59)534210
Valve disease, mild or absent (n = 199)94913.5
Valve disease, moderate or severe (n = 51)713139
Miscellaneous findings absent (n = 143)776413
Miscellaneous findings present (n = 107)47344
HHU=handheld ultrasound; PE=physical exam; LV=left ventricle; RV=right ventricle
Source: J Am Coll Cardiol Img 2014;7:983–990
   

The between-group differences are the mean differences at 12 weeks, adjusted for study site, presence or absence of coronary artery disease, and blood pressure as measured at baseline. CPAP denotes continuous positive airway pressure, NSO nocturnal supplemental oxygen, and HLSE healthy lifestyle and sleep education.

Source: 2013 Lancet;382:1329-1340.