Point-of-care Ultrasound in Morbidity and Mortality Cases in Emergency Medicine: Who Benefits the Most?

Who Benefits the Most?

Andrew J. Goldsmith, MD, MBA; Hamid Shokoohi, MD MPH; Michael Loesche, MD, PhD; Ravish C. Patel; Heidi Kimberly, MD; Andrew Liteplo, MD

Disclosures

Western J Emerg Med. 2020;21(6):172-178. 

In This Article

Discussion

An aggregate review of M&Ms over a one-year period showed the perceived potential for POCUS to prevent M&M. This is the first report of which we are aware that examines POCUS through a hospital's M&M conference. In this pool of high-yield cases we determined that in up to 33% (25/75) of cases of M&M, POCUS had not been done but might have helped to prevent the M&M. Of course, POCUS findings would be only one of many needed pieces of information that could have changed management, identified diagnoses, or decreased time to diagnoses.

Whether or not POCUS would have been done is harder to assess. An EM attending with US training stated that based on the retrospective information about the case, he would have personally performed a POCUS in only 52% (13/25) of cases. It should be noted that an US EM attending's usage is likely to be higher than that of an EM attending without specialized US training; thus, this number may be an overestimation. In the rest of the cases where it was felt that POCUS might have prevented M&M, the US EM attending did not think that he would have performed a POCUS. For many of the cases, the US findings might have been considered to be advanced (ie, endocarditis, focal wall-motion abnormalities) and probably fell outside the scope of standard POCUS in EM. As emergency physicians become more and more facile with POCUS, it is possible that these applications may become more commonplace.

In this study, M&M was used as a surrogate of critically ill patients with significant adverse outcomes as it has been identified in previous literature within EM.[16,17] Our data speak to the importance of POCUS use in the routine care of patients while in the ED, especially in those who are critically ill.

One of the most difficult aspects of POCUS utilization is knowing in which patients to use it. Even when an emergency physician has competence in performing, interpreting, and integrating US, if it is not done then there is no benefit to the patient. Having greater diagnostic accuracy earlier in a patient's work-up could potentially allow for optimization of care during the golden hour with streamlined treatment, better decision-making about imaging, earlier consultation, and more accurate disposition. However, POCUS takes time and so performing it in every patient may not be an efficient use of ED resources or physician time. Our results showed that patients with chief complaints of chest pain, shortness of breath, and trauma made up approximately 80% of the M&Ms where POCUS was thought to be able to help prevent its outcome. This is not surprising as chief complaints of chest pain and shortness of breath comprise a large number of ED visits and are often caused by diagnoses with high mortality.[18] Our data also show that vital sign abnormalities were common in M&M cases where POCUS may have made a difference. Specifically, patients who were tachycardic and/or hypoxic were the most likely to benefit from POCUS. This information can be used to guide physician decision-making with critically ill patients and clinical protocols in EDs.

Additionally, these data can inform ultrasound education in EM residencies and support the idea of advocating for "POCUS first" algorithms in patients presenting with chest pain, shortness of breath, hypoxia, and/or tachycardia. As FAST has been integrated into the Advanced Trauma Life Support algorithm for trauma patients, cardiac POCUS is starting to be incorporated into Advanced Cardiac Life Support for routine cardiac arrest care in the ED.[19] It may be reasonable to develop similar algorithms for patients with hypoxia and/or tachycardia or with chief complaints of chest pain and shortness of breath with the intent of improving patient outcomes. Although it is not reasonable for all patients, highly targeted POCUS for a specific patient population with cardiopulmonary complaints is reasonable. Further, this may help educators teach trainees which patients clinically may have the highest benefit of a POCUS when clinicians must triage multiple sick patients at once. A few studies have attempted to describe their integration;[12,20] however, further research is needed on specific patient outcomes.

Of the 75 cases that were presented to M&M, in 9% (7/75) POCUS may have been one component that negatively impacted the case. To inform educational endeavors, we analyzed the results by the three components of POCUS: 1) performing the POCUS and acquiring images; 2) interpreting the images; and 3) integrating the findings into clinical care. In half of the errors, the POCUS was both done and interpreted correctly, but the integration of clinical findings was flawed. This knowledge has important implications on POCUS education. POCUS curricula in EM residencies are comprised largely of scan shifts in which acquisition and interpretation of images are heavily emphasized, but integration of findings may not be. These data highlight the importance of also focusing integration of POCUS findings into clinical care needs and emphasize the need for comprehensive POCUS training.

In a quarter of the errors, POCUS was incorrectly performed. Both of the cases were related to procedural guidance. It is not entirely clear how POCUS was or was not involved in these cases as we did not perform image review, but this does speak to the importance of skills training, perhaps in simulation settings. Physicians from non-EM specialties were involved in some of these procedural errors and highlights the need for POCUS education to all services who care for patients in the ED. Finally, interpretation of POCUS was the issue in a quarter of the errors. In both of these cases (necrotizing fasciitis and focal cardiac tamponade), findings extended beyond the traditional questions that POCUS answers. This highlights a vulnerability of POCUS, in that even in these cases we as providers are responsible for images that we acquire and their findings. Identifying examples of these vulnerabilities through review of M&M cases can be one tool that we as educators use to further the education of our physicians. Although POCUS was involved in 9% of adverse cases associated with M&M, it does not suggest that US in and of itself is a dangerous tool. Rather, it underscores the importance of competence in using US and the need for high quality and continuing training.

The notion of POCUS identifying hard-to-make diagnoses is also supported by our study. Mechanisms of how POCUS was perceived to help prevent M&M were noted and quantified. POCUS was perceived to be most potentially useful in its ability to identify missed diagnoses (92% of cases) and decrease the time to diagnosis (92%). Given this ability, the threshold for performance of US in all patients with a questionable diagnosis should be very low. Ultimately, our study supports the idea that US may have a role in decreasing diagnostic and procedural errors, thereby improving patient care. However, it also shows that if US is done it needs to be done well, accurately, and integrated into patient care correctly.

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