POCUS – Chance or Risk?POCUS – Chance oder Risiko?
14 December 2018 (online)
“Point-of-Care Ultrasound” (POCUS) is a term that is currently on everyone’s lips. Its uses vary and it is often equated with focused ultrasound, emergency ultrasound, and pocket ultrasound, for example. The increase in the use of POCUS has resulted not only in a major atmosphere of change and new opportunities for ultrasound but also in a general sense of uncertainty. Some colleagues even view POCUS as a threat with regard to quality assurance. Because POCUS will play a major role in the clinical routine in the future, it seems important to ensure clear understanding and standardized usage of the term. POCUS is a bedside ultrasound method that covers examinations from head to toe. It not only focuses on the macroanatomy and pathology but also allows direct evaluation of functional anatomical aspects, physiology, pathophysiology, and hemodynamics and provides support during interventions. Treating physicians with diverse areas of specialization and an interest in a specific organ pathology, particular diseases/symptoms, or an intervention personally perform examinations in various situations (emergency admission, consultation hours, intensive care unit, operating room, etc.) in real time while determining the scope and interpreting the findings. Another significant component of POCUS is the concept of focused ultrasound. Focused means that the examiner is limited to one or more yes-no ultrasound questions (from simple to complicated) and does not perform a conventional comprehensive organ examination or examination of a region or functional unit. The focus is less on ultrasound as an isolated diagnostic imaging method and more on the expansion of the clinical examination. This provides the examiner with an additional tool for making reliable and optimal management decisions and for monitoring patients as needed.
Conventional comprehensive ultrasound, in contrast, is divided into various well-defined anatomical regions, like the abdomen, lung, vessels, nerves, heart, soft tissues, and musculoskeletal system and is performed by a physician specialized in the particular type of imaging at a specialized medical practice or ultrasound department. It includes comprehensive examination of an individual organ, an anatomical or functional unit or a region with reliable criteria to detect or rule out the presence of certain diseases/injuries. 2 articles in this issue provide examples of this. The study on the role of high-resolution ultrasound in the follow-up of cervical lymph nodes after RCT shows that intranodal necrosis and changes in the hilar vascularization pattern can be clearly visualized and accurate control of dynamic changes is possible in sonographic tumor follow-up. A further study shows that US-guided HIFU treatment can be reliably performed even in the case of locally advanced pancreatic cancer with involvement of the mesenteric vessels and extensive collateral circulation. A significant consideration regarding the quality of ultrasound is that the method is highly examiner-dependent. Therefore, a further study in this issue shows that the interobserver agreement for ESCULAP seems better than for CEUS-LI-RADS since the perception of contrast washout can vary greatly between individual examiners. The use of high-resolution ultrasound as an established and validated method thus allows more extensive differentiated diagnosis in the hands of experienced specialists and is also suitable for monitoring therapeutic measures.
There are 2 main directions or training programs in ultrasound: 1. Conventional comprehensive ultrasound which is performed by a specialist or at a specialized medical practice usually as a referral and 2. POCUS which is performed by the treating physician as a focused examination in real time at the patient’s bedside with immediate interpretation. Therefore, the differences essentially relate to the examination location, the qualifications of the examiner, and the scope and objective of the examination.
In this connection, it is necessary to determine whether POCUS poses a threat to conventional comprehensive ultrasound or represents a risk to the quality of ultrasound examinations. This concern is evidenced by the fact that POCUS is at the bottom of an examiner-expert pyramid. In this regard POCUS is viewed as acceptable for the intended purpose but is of lower quality than a complete ultrasound examination. Consequently, the fear is that POCUS will be used ubiquitously, resulting in a loss in quality and thereby lowering the value of the method. However, this does not take into consideration the fact that a limited examination cannot be equated a priori with a low examination quality in the way that a small circle only differs quantitatively and not qualitatively from a large circle. The learning pyramid is static and does not allow any space for the advantages of POCUS over comprehensive ultrasound. Therefore, for example, the speed and availability of ultrasound examinations are lost.
Consequently, there is no doubt that comprehensive ultrasound performed by a specialist is of great importance and cannot be replaced by POCUS. However, it is also correct that ultrasound performed by a specialist is only available on a limited basis and a complete examination is often not necessary or there is insufficient time for such an examination. 6 measures are needed to ensure that traditional comprehensive ultrasound and POCUS complement one another rather than compete with one another: 1. The concept of the conventional US learning pyramid must allow room for recognition of the similarities and differences between the methods and the fact that POCUS represents a new readily available but limited ultrasound method. 2. Standardized, evidence-based training curricula and standards for POCUS must be created and various expert levels for training must be defined. 3. Tutors need to be trained and training centers for those interested in POCUS must be provided. 4. Ultrasound experts need to develop guidelines as to when POCUS patients would profit from a referral to a specialist and should be involved in training. 5. It must be recognized that POCUS is not easier to perform even though POCUS examinations are faster and limited in their scope. The POCUS spectrum ranges from simple to complicated. 6. POCUS examiners must undergo good training and supervision, observe the POCUS principles, and avoid overinterpretation and misinterpretation.
Technological advancements in the form of mini-devices and hand-held devices ([Fig. 1]) is the industry’s response to the POCUS concept. Wireless probes can be connected via Bluetooth and WiFi to a screen (smartphone, tablet, etc.). Personalized ultrasound devices will reach a quality and price level in coming years that will allow even greater use. This development will have major effects on the clinical routine in that ultrasound will ultimately replace the stethoscope. This is also not a disadvantage but rather a sign of the potential of ultrasound. The clinical examination will experience a major increase in value. By using POCUS as a triage function, many important and fundamental diagnoses can be made or ruled out. The routine use of ultrasound in invasive interventions is inevitable and will increase safety for patients. Therefore, POCUS does not represent a risk for ultrasound or patients. Rather, POCUS provides a new opportunity. It provides the possibility of improving diagnostic imaging in the clinical routine. We must meet this challenge. Our 3 national societies anticipated the development of POCUS and its potential and with the creation of the emergency certificate established a first important principle. Emergency medicine is not the only area that can profit from POCUS. Except for, for example, psychiatry, prenatal diagnosis, and pediatric hip ultrasound, many areas of specialization can benefit from POCUS. Therefore, a new certificate of competency for POCUS, which is open to all physicians, was adopted by SGUM 1 year ago. It includes a range of areas of specialization (from anesthesia to orthopedics/rheumatology). Our 3 societies have the opportunity to provide all clinical physicians, whether general practitioner or specialist, with high-quality access to POCUS with the goal of perfecting the clinical examination and providing our patients with the best possible treatment. If we choose this path, it is important to know what the ultimate result of this new approach will be. According to the literature, POCUS can reduce the time to diagnosis, the number of CT examinations, and costs, for example. However, evidence of the effect on patient outcome such as mortality and morbidity is still lacking. Research in this area should be intensified – a task for our house journal.
- 1 Moore CL, Copel JA. Point-of-Care Ultrasonography. NEJM 2011; 364: 749-757
- 2 Weile J, Brix J, Moellekaer AB. Is point-of-care ultrasound disruptive innovation? Formulating why POCUS is different from conventional comprehensive ultrasound. Crit Ultrasound J 2018; 10: 25