Cite as: Myhre C, Ip V.  Learning POCUS, part 1: the benefits of an early introduction. ASRA Pain Medicine News 2023;48. https://doi.org/10.52211/asra110123.008.

Introduction

Point-of-Care Ultrasound (POCUS) is becoming more widespread as a diagnostic tool in clinical practice with some even suggesting that it is the new stethoscope.¹ It is a bedside tool that is simple to learn; yet the clinical relevance of POCUS is not reflected in undergraduate medical education.² POCUS exposure in medical school is often informal and inconsistent, resulting in variable POCUS skill and knowledge between residents.³ As such, there is growing support for POCUS training to begin in medical school.⁴

In 2014, a national survey on undergraduate medical education reported that only 50% of medical schools in Canada have incorporated POCUS within the curriculum, the majority of those dedicating less than 5 hours per year.⁵ While these numbers have likely increased in recent years, POCUS in medical education remains insufficient.² As evidence of this ongoing opportunity for improvement, a recent conference hosting 14 out of 17 Canadian medical schools was held to identify strategies to overcome barriers in implementing POCUS in undergraduate medical education.² Despite recent efforts to reorient Canadian medical school curricula in keeping with current medical technology, the need for, and lack of, adequate formal POCUS training persists.

As medical technology becomes more advanced and accessible, medical education must embrace its use to prepare a well-rounded generalist for residency training.

There is a notion that undergraduate medical education serves to lay the groundwork for a generalist physician to have broad knowledge and understanding of anatomy, physiology, pathology, diagnostics, and treatment within the clinical context. There is also a culture within medical education that regards POCUS as a specialized clinical competency despite it being a necessary skill of a postgraduate physician for most residency programs. As medical technology becomes more advanced and accessible, medical education must embrace its use to prepare a well-rounded generalist for residency training.

Why Should POCUS Be Incorporated into the Medical School Curriculum?

The clinical relevance of ultrasound lies in diagnostic accuracy. Discrepancy rates between clinical diagnosis and autopsies is variable, and it is reported by that 10%-30% of patients receive major ante-mortem misdiagnosis.^6-8 To further illustrate the need to reduce diagnostic errors, the Agency for Healthcare Research and Quality commissioned a systematic review examining diagnostic errors made in emergency departments in 2022.⁹ It was shown that out of 130 million United States emergency department visits, 5.7% of patients were misdiagnosed with misdiagnosis-related harms resulting in 2% of patients.⁹ These comparatively lower rates of misdiagnosis still identify 2.5 million harms with 350,000 of those patients sustaining permanent disability or death.⁹ These statistics should not serve to criticize an individual’s inevitable human error, but to identify system-level opportunities for improvement. Although POCUS may not replace other means for diagnosis, in trained hands, it can help guide bedside decision making and clinical management. 

POCUS has potential applications as a cost effective, systemic strategy to mitigate human error if image interpretation is accurate. This supports the argument that early exposure to hands-on POCUS training in medical school better positions residents to further refine their techniques in the real-world patient care setting. A study conducted by the Norwegian University of Science and Technology implemented cardiac and abdominal ultrasound screening of internal medicine patients using a pocket-sized ultrasound. ¹⁰ As a result, 18% (36 patients) had their main diagnosis changed, while the initial diagnosis was confirmed in 19% (38 patients).¹⁰ Further, a significant additional diagnosis unrelated to the principal diagnosis was made in another 9% (18 patients).¹⁰ Overall, this use of POCUS made critical diagnostic changes in 1 out of 5 patients and was reported to have added less than 10 minutes to usual care diagnostics.¹⁰ As such, POCUS proficiency enables future physicians to access and interpret critical health information when making life-altering treatment decisions. Medical education must reflect the significance of POCUS in practice to further optimize its use.

Challenges and Solutions to Integrate POCUS into Medical School Education

To address the challenges of teaching POCUS diagnostics, Queen’s University in Canada experienced success in utilizing self-directed electronic modules to teach ultrasound image interpretation, which could be easily integrated into medical curricula.¹¹ However, this study also found that direct guided training was a crucial component of developing scanning technique, which requires expert faculty, small group teaching sessions, and individual, hands-on practice time.¹¹ There is evidence to support utilizing a flipped-classroom training program to mitigate the burden of recruiting expert faculty.³ An effective student-led ultrasound curriculum was implemented in California where second-year medical students, who had completed an ultrasound curriculum during first year, instructed first-year students.³ This was cost-effective, reduced faculty time requirements, and enabled small group learning, all while developing medical student leadership and teaching skills.³ Nevertheless, a flipped classroom cannot replace physician-led POCUS training, but rather it may facilitate hands-on practice time, ultimately improving operator skill retention.³

Another barrier is the limited time available to provide POCUS education within an already dense curriculum. The minimum number of training hours is uncertain and may be operator-dependent, as the literature reports a wide range of time dedicated to POCUS training by medical schools that offer such education.¹² POCUS is a hands-on technique whereby practical time is positively correlated with both diagnostic accuracy and procedural success.¹³ 

Despite these barriers, there is evidence of success when implementing POCUS training in undergraduate medical education. A review was conducted of 12 medical schools providing cardiac POCUS training within their curriculums and overall, these schools reported positive learning outcomes for medical students in the short term.¹³ POCUS was incorporated in anatomy, physiology, and physical examination lessons, and as a result, medical students were able to recognize simple disease states, such as valvular regurgitation and pericardial effusion.¹³ POCUS training has enabled medical students with minimal clinical training to acquire and interpret POCUS imaging with a diagnostic accuracy of 93.2% for basic pathology (eg, pleural effusions, lung comets, cholecystitis, abdominal free fluid, etc.).¹⁴ Mouratev et al. reported that medical students with limited instruction demonstrated higher accuracy in measuring liver size by using ultrasound than an experienced board certified internist measuring via physical exam.¹⁵ These positive short term outcomes have brought attention to the benefit of developing longitudinal POCUS curricula within medical schools to instill a deeper understanding of ultrasound technique and use while improving the longevity of this important skill for residency.¹² Nonetheless, POCUS competency standards within undergraduate medical education are still to be determined, which will be discussed in Part 2 of Learning POCUS. 

Rather than compartmentalize ultrasound as a skill to be acquired during specific residencies, incorporating ultrasound into anatomy and physiology lessons in the undergraduate medical curriculum enhances content retention and provides clinical relevance, positioning the student for success and seamless transition in clerkship rotations.¹⁵ Further, longitudinal, spaced repetition promotes long-term skill retention.^2,16,17 Finally, early and continued exposure to POCUS is in keeping with the curricular structure of modern medical education as students revisit key concepts longitudinally throughout medical school rather than learn a concept in depth during a single encounter.

Conclusion

Realistically, POCUS will not be mastered as a diagnostic tool or procedural aid without several years of experience. A formal introduction to POCUS in the preclinical years would facilitate this skill acquisition while building confidence in future physicians of diverse specialties to optimize POCUS in their practice. Early POCUS education is ultimately an investment in promoting good patient care. Technological developments optimize patient care, medical education must reflect these advancements to prepare future physicians for the new clinical landscape. 

Vivian Ip, MBChB, MRCP, FRCA, is a clinical professor at the University of Alberta Hospital in Edmonton, Canada.

References

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