Thursday, April 5, 2018

Applications, Barriers, and Future of Point of Care Ultrasound in Limited Resource Communities

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Author: Janette Magallanes, MS4
Medical Student
Indiana University School of Medicine

The most common use of point-of-care ultrasound (PoCUS) in the emergency department (ED) is in evaluating trauma patients by assessing for pericardial effusion, pneumothorax, and intra-abdominal hemorrhage. The advantage in such acute settings primarily lies in ultrasound’s ability to minimize delays and quickly narrow down a differential diagnosis. Although there is minimal data on the impact of ultrasound (US) findings on patient outcomes in underserved rural communities, there is data showing that portable ultrasound findings have led to changes in patient management in up to 70% of cases.[1]

Applications of PoCUS
Other relevant applications have been found for PoCUS throughout the world. It has been found to have utility in diagnosing empyema, intussusception, retinal detachment, and fractures, as well as in verifying endotracheal tube placements in neonates and in cardiopulmonary resuscitation.[1] More relevant to developing countries, protocols have been developed to include PoCUS in risk stratifying patients with malaria, predicting progression of dengue fever, and even assessing lymphatic filariasis.[1] There is no question that there is enormous potential in the utility of PoCUS all over the world.


Obstetrics and gynecology is perhaps the most widely known use of ultrasonography. According to the Agency for Healthcare Research and Quality, in 2014 there were 12.7 per 1000 ED visits in the United States with first-listed diagnosis in the maternal/neonatal category.[2] In a recent study, midwives in rural Kenya who had no prior exposure to ultrasound were given a five-week course on basic ultrasonography skills. After the short course they were able to perform scans with a 99.63% accuracy, demonstrating how even brief instruction in ultrasonography can change the way medicine is practiced and improve patient care in limited-resource areas.[3]

The portability of PoCUS makes it a versatile tool for triaging patients during disasters. In areas with poor infrastructure, where electricity may not be readily available, battery-operated PoCUS becomes extremely valuable. PoCUS has been used in Guatemala during a relief effort after a mudslide, where it was found that a single transducer sufficed for most needs.[4]

Barriers
One of the biggest barriers is the cost of the equipment. The newest PoCUS products currently on the market cost about $8,000-$20,000. This is more economical than the standard counterparts costing upwards of $100,000 per device, but still presents a barrier to widespread availability.

Recent studies are showing that another barrier, perhaps an even larger barrier, is the lack of ultrasonographers and trained physicians to operate the equipment and interpret the results.[5] Since the marked expansion of bedside ultrasound in the ED, the American College of Emergency Physicians (ACEP) states that PoCUS has “established itself as a standard in the clinical evaluation of the emergency patient.”[6] As a result, in their updated guidelines, they are requiring emergency medicine residents to have a two-week ultrasound rotation in the first year and at least one week during each subsequent year of residency, for a minimum of eighty hours of dedicated emergency ultrasound training during residency.

From the Kenya study, we can see that basic ultrasound training is feasible in a short amount of time, so why aren’t physicians in remote sites taking these courses? Often, for providers to seek this additional training, they must be able to take time off from their practice and pay out-of-pocket for the course. Physicians practicing in rural communities also find it difficult to maintain their ultrasound skills due to lower patient volumes in some sites. Many also opt not to use PoCUS out of fear of litigation.[1] In rural sites, emergency physicians have a difficult time obtaining feedback regarding the quality of their scans, which makes it more difficult to integrate their findings for clinical decision making. However, studies show that emergency physicians are more likely to be sued for not using PoCUS, since it is within their scope of practice, than they are for failing to correctly interpret a scan.[1]

Future of PoCUS Abroad and Potential Solutions to Barriers
Teleradiology is one solution whereby frontline staff can electronically send the scans for review by a radiologist at another site. This ensures quality, while also contributing to the maintenance of ultrasonography skills by providing feedback about the scans. Telesonography training can be a viable option for reducing the financial burden of obtaining training for healthcare providers in further sites. It is also a great tool for helping healthcare providers to maintain their skills and stay current with the indications and applications of PoCUS.

Additionally, biomedical companies are working to make the techynology more readily accessible via increased portability and affordability. Currently, a startup company, the Butterfly Network, is working to release a PoCUS device known as the Butterfly iQ that has obtained recent Food and Drug Administration (FDA) clearance for multiple applications, and plans to bring the device to the market at about $2000 per device.[7] The ability to decrease the price lies in the manufacturing of the product. Instead of the traditional piezoelectric crystals (which are very expensive to produce) that traditional transducers use, Butterfly Network has created a substitute chip that also eliminates the need for multiple transducers for visualization of different anatomical compartments. Butterfly Network is also working to integrate artificial intelligence into their Butterfly iQ that would evaluate the quality of the scan, aiding the ultrasonographer with proper probe positioning.[7]

Conclusion
PoCUS has become a standard of care in the emergency department in the United States and other resource-rich countries. With such a broad spectrum of applications, there is no question that it has great potential in limited-resource communities as well. There are several barriers to expanding the use of PoCUS in rural communities including from lack of training, difficulty maintaining ultrasonography skills, fears of litigation, lack of quality assurance, and cost of equipment. The more we study and learn about some of these barriers, the more we can learn how to best overcome them. Teleradiology can provide solutions to some of these barriers, and with the improving technology, there is significant potential to make ultrasound an affordable tool, ultimately improving the quality of patient care in rural communities.

References:

1. Micks T, Sue K, Rogers P. Barriers to point-of-care ultrasound use in rural emergency departments. CJEM. 2016;18(6):475-9.

2. Moore BJ (IBM Watson Health), Stocks C (AHRQ), Owens PL (AHRQ). Trends in Emergency Department Visits, 2006–2014. HCUP Statistical Brief #227. September 2017. Agency for Healthcare Research and Quality, Rockville, MD. www.hcup-us.ahrq.gov/reports/statbriefs/sb227-Emergency-Department-Visit- Trends.pdf

3. Vinayak S, Sande J, Nisenbaum H, Nols√łe CP. Training midwives to perform basic obstetric point-of-care ultrasound in rural areas using a tablet platform and mobile phone transmission technology: A WFUMB COE Project. Ultrasound Med Biol. 2017;43(10):2125-32.

4. Dean AJ, Ku BS, Zeserson EM. The utility of handheld ultrasound in an austere medical setting in Guatemala after a natural disaster. Am J Disaster Med. 2007;2(5):249-56.

5. Shah S, Bellows BA, Adedipe AA, et al. Perceived barriers in the use of ultrasound in developing countries. Crit Ultrasound J. 2015;7(1):28.

6. Ultrasound Guidelines: Emergency, point-of-care and clinical ultrasound guidelines in medicine. Ann Emerg Med. 2017;69(5):e27-54.

7. Strickland E. New "ultrasound on a chip" tool could revolutionize medical imaging. October 2017. https://spectrum.ieee.org/the-human-os/biomedical/imaging/new-ultrasound-on-a-chip-tool-could-revolutionize-medical-imaging. (Accessed December 29, 2017).

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