Point-of-care ultrasound (POCUS), long a staple of emergency medicine, is beginning to make its presence known in primary care practice.
Whether through handheld probes that can connect to smartphones or standalone cart-based systems, POCUS technology has evolved to the point where it's available in a wide variety of inpatient and outpatient settings. It can be used to estimate systolic function, look for ascites, and differentiate between an abscess and cellulitis, for starters. Even medical schools are now outfitting students with pocket devices, and ACP recently released a statement in support of the technology.
“It's really become an all-purpose tool for many internists, and it's used not only for general information gathering and expanding the physical diagnosis but also used for augmenting confidence in performing safe procedures,” said Davoren Chick, MD, FACP, ACP's Senior Vice President for Medical Education.
For Mike Wagner, MD, FACP, an internal medicine physician at the University of South Carolina School of Medicine in Greenville who has completed a one-year ultrasound fellowship, incorporating POCUS into annual physical exams offers a more comprehensive assessment of anatomy and physiology. It can also be useful as an adjunct for patient counseling.
“For example, if you see the patient has left ventricular hypertrophy, it's a good opportunity to discuss their blood pressure. If you see that they have a fatty liver, it's a very insightful way to get a better social history and discuss their drinking habits,” he said.
Dr. Wagner said he uses POCUS whenever he has a clinical question involving the heart, lungs, or abdomen. He uses an integrated, structured approach called the PEARLS examination (Parasternal, Epigastric, Anterior Lung [and/or Apical], Right upper quadrant, Left upper quadrant, and Suprapubic), the details of which were published in Southern Medical Journal in July 2018.
POCUS can improve both the patient experience and clinical efficiency, according to Dr. Chick. “If [physicians] can perform this technique at the bedside, they don't have to inconvenience the patient or potentially add to their cost of care by making them travel to another site or perhaps on another day to wait for a procedure that can be done right there and then at the bedside by an experienced clinician,” she said. “And the clinician can make a more rapid and informed diagnosis when they receive information that helps them to either feel more comfortable with or perhaps expand their diagnosis.”
Not warranted everywhere, yet
Prior concerns over POCUS centered around its cost-effectiveness, but today the primary issue may be its widespread proliferation in cases when it might not be needed.
Andrew Coyle, MD, an assistant professor of internal medicine at Mount Sinai Hospital in New York, describes himself as slightly skeptical about POCUS, mostly due to the lack of historical data showing clinical utility, and does not currently use it himself.
“What would convince me is if we had more data saying that ultrasound technology as an add-on to the physical exam really improved our diagnostic accuracy, and with the exception of a few studies, that doesn't really exist,” he said. “I think we have enough data to say that if you're interested, it's potentially a great idea that may bring the patient and exam into focus and may be somewhat helpful, but I don't think we're at the point from a data perspective where we can say as a practice or as a field that it's an essential skill for the clinic.”
Proponents of POCUS argue that it saves physicians time by providing almost instant information, but Dr. Coyle said this isn't necessarily a benefit in primary care.
“In the clinic where we're doing important work but patients aren't critically ill and time isn't of the essence, is it necessary to have that?” he asked. “For example, it may be interesting for me in my stable patient with heart failure to put an ultrasound probe on their chest and see how their heart's doing, but I don't necessarily need that information immediately. Is there really an advantage to me doing it versus sending them to radiology to do a formal echo and get that same information, especially with all the time pressures in clinic?”
Kang Zhang, MD, FACP, of Providence Internal Medicine Residency in Spokane, Wash., uses POCUS both in his inpatient and outpatient practice as well as on home visits but acknowledged the challenge of time for a busy clinician.
“In our clinic, I have the convenience of having an ultrasound machine across the hall—I know how to use it, I teach my residents how to use it—but when you're stuck on a 15- to 30-minute visit, I can see people not wanting to use this,” he said. “Additionally, there's a whole workflow process that is needed to ensure the clinical encounter goes smoothly. From my own personal experience, there are a lot of steps where things can go wrong and eat up time. For example, there have been times where I've had to track down ultrasound gel or it has taken five minutes just to get the patient ready and positioned. All that takes time.”
Another challenge of using POCUS in primary care “is when the treating provider steps outside of their training or their comfort zone to make decisions that they shouldn't be making or making interpretations of something that they are not trained to do,” said ACP Member Thomas Robertson, MD, an internal medicine physician at Allegheny Health Network in Pittsburgh. However, for trained clinicians who are knowledgeable about and comfortable with the technology, there are few risks, he stressed.
Dr. Robertson became fascinated with POCUS as a medical student and began developing ultrasound curricula as a resident. However, he said he found that the only way to really learn it is by doing. “You need to go around to patients and practice both image acquisition and then image interpretation,” he said.
ACP is actively helping internal medicine physicians improve both their knowledge and their hands-on skills by offering several live ultrasound courses for various care settings, as well as an array of interactive online learning tools, Dr. Chick said.
“We believe strongly that structured education to build cognitive knowledge and supervised direct hands-on training to build physical skills are necessary for the appropriate implementation of point-of-care ultrasound,” she added. “A growing number of medical students and residents are learning these skills during the course of their training, but many practicing physicians are seeking their POCUS training through ACP because they didn't have the benefit of training with these machines.”
While POCUS is now part of his daily practice, Dr. Zhang noted a slow learning curve and said he initially fell victim to a false sense of confidence that didn't match his initial skill. “As I did more and more, I found out the nuances of POCUS and how just moving your probe by a quarter of an inch can really change what the image would look like,” he said. “At the very beginning [I had] this false sense of security, but now I respect the machine more and the utility of it.”
He added, “POCUS can be very, very dangerous if you're not asking the appropriate questions, and even more dangerous if you abandon your clinical judgment.” When teaching residents now, Dr. Zhang tells them, “Don't use POCUS as a crutch to lean on. Use it as a compass to guide you.”
“Physicians always have to keep in mind limitations of most of their equipment and their own abilities,” Dr. Chick added. “Just like physicians are not going to necessarily perform an invasive procedure based on an indeterminant heart sound that they detect with their stethoscope, we certainly don't train people to perform an invasive procedure without a full understanding of what they're looking at in an ultrasound image.”
To bill or not?
Even though the cost of POCUS devices has come down, economical questions still remain, especially with regard to billing and reimbursement.
“Since I work at an academic center, most of our studies are not submitted for billing,” Dr. Wagner said. Even so, the cost is worth it, he noted, and billing at his facility is changing as POCUS is implemented across the entire health system.
Dr. Robertson said that while cost-effectiveness of POCUS can be difficult to study, the technology can improve clinical outcomes, reduce procedural complication and failure rates, and help reduce time to appropriate treatment, as well as radiation. “Now, whether or not internists are billing for ultrasound in terms of revenue generation, it's dependent on the hospital [and] on the practicing clinician, but I do think ultimately our goal is to provide the best care for our patients, and point-of-care ultrasound is a tool that we should use to provide the best care for our patients,” he said.
Dr. Robertson only bills for POCUS when he is using it to guide a procedure and when the images are saved and permanently stored in the electronic medical record, not when performing diagnostic imaging. Like Dr. Wagner, he believes the cost is worth it. “It's really the future of medicine and providing the best care, so it's absolutely worth the investment,” he said. “On the grand scheme in terms of what health care costs are, it's actually quite a minimal investment.”
One tip Dr. Chick offered was to potentially share POCUS devices with other services if possible. “You don't have to have one machine per person,” she said. In addition, handheld machines are useful and more affordable. However, she said, “they have some downsides in terms of how the images are processed and how easy it is to get those images into your electronic health record, for instance.”
Future studies should focus on providing more evidence for the specific diagnostic accuracy of particular ultrasound findings, according to Dr. Chick. For example, she said, “Diagnostic accuracy for venous thrombosis is fairly well established, but the specific techniques that have the most accuracy could be further refined.”
Dr. Wagner said it will become easier to do multicenter studies with larger numbers of patients as more primary care physicians become comfortable and proficient with POCUS. As POCUS becomes more portable and user-friendly, he said, it should be viewed less as a diagnostic imaging method and more as an essential clinical skill.
“This is going to be, or in many ways already is, a standard element in the toolbox of an internal medicine physician at the point of care,” Dr. Chick said. “This is certainly well within the internal medicine scope of practice, and I think you're going to see more and more internal medicine physicians training to use this skill as they would any other diagnostic or physical examination aid.”