SGEM#295: Teacher Teacher – Tell Me How to Do It (Diagnose a PE)

Date: June 9th, 2020 Guest Skeptic: Dr. Chris Bond is an Emergency Medicine Physician and Assistant Professor at the University of Calgary. He is also an avid FOAM supporter/producer through various online outlets including TheSGEM. Reference: Westafer et al. Provider Perspectives on the Use of Evidence-based Risk Stratification Tools in the Evaluation of Pulmonary Embolism: A Qualitative Study. AEM June 2020. Case: A 63-year-old female presents to the emergency department (ED) with chest pain for the past eight hours. It is pleuritic, worse with certain movements and associated with some shortness of breath. Her vital signs are within normal limits and oxygen saturation is 95% on room air. An ECG, chest x-ray and troponin are all within normal limits and she has no calf swelling or tenderness. She does have a previous history of DVT/PE 12 years ago after returning from a transatlantic flight. She has also been doing more work around the house and lifting the past few weeks because of COVID and has some mild chest wall tenderness on palpation. The remainder of her Wells’ criteria are unremarkable. How do you proceed in evaluating this patient for pulmonary embolism (PE)? Background: Pulmonary embolism is a common ED diagnosis with an estimated 1-2% of all patients presenting to United States EDs undergoing CT for suspected PE (1). However, less than 10% of these scans show PE (2-4). We have covered the topic of PE frequently on the SGEM. SGEM#51: Home (Discharging Patients with Acute Pulmonary Emboli Home from the Emergency Department) SGEM#118: I Hope you Had a Negative D-dimer (ADJUST PE Study) SGEM#126: Take me to the Rivaroxaban – Outpatient treatment of VTE SGEM#163: Shuffle off to Buffalo to Talk Thrombolysis for Acute Pulmonary Embolism SGEM#219: Shout, Shout, PERC Rule Them Out SGEM#277: In the Pregnant YEARS – Diagnosing Pulmonary Embolism SGEM#282: It’s All ‘bout that Bayes, ‘Bout that Bayes- No Trouble – In Diagnosing Pulmonary Embolism There are multiple validated risk stratification tools to evaluate for PE and reduce inappropriate testing, including the Pulmonary Embolism Rule Out Criteria (PERC), Wells’score, YEARS algorithm and D-Dimer testing (5-7). There have also been more recent adjustments to D-Dimer threshold based on clinical probability as calculated by a trichotomized Wells score (8). Unfortunately, clinician uptake of these validated tools has been incomplete, with some ED studies finding 25% of patients who warranted no laboratory or imaging studies still received testing (4, 9-12.) Low-value testing increases costs, ED length of stay and subjects patients to unnecessary ionizing radiation and risk of anaphylaxis from intravenous contrast dye (13-14).  Moreover, false positives CT scans are common and estimated to be between 10-26%, resulting in unnecessary anti-coagulation and risk to patients (15-17). This can ultimately lead to over-testing, over-diagnosing and over-treating. The American Board of Internal Medicine (ABIM) started the project called Choosing Wisely to try and mitigate this problem. The SGEM looked at this imitative on an SGEM Xtra. The American College of Emergency Physicians (ACEP) is part of the Choosing Wisely program and has a number of recommendations. One of the recommendations is on CT scans for ruling out PE. They have encouraged physicians to” “Avoid CT pulmonary angiography in emergency department patients with a low-pretest probability of pulmonary embolism and either a negative Pulmonary Embolism Rule-Out Criteria (PERC) or a negative D-dimer.” ACEP 2014 The Right Care Alliance (RCA) was established in 2015. Certainly, patients at times need less care but they also at times need more care. This group’s goal is to advocate for the goldilocks zone of care, not too much but also not too little (SGEM Xtra). Clinical Question: What are the barriers and facilitators to the uptake of evidence-based practice in the ED evaluation for pulmonary embolism? Reference: Westafer et al. Provider Perspectives on the Use of Evidence-based Risk Stratification Tools in the Evaluation of Pulmonary Embolism: A Qualitative Study. AEM June 2020. Dr. Lauren Westafer As this is a qualitative study, we will use a modified PICO question Population: Emergency physicians Interest: The use of evidence-based risk stratification tools Context: The evaluation of acute pulmonary embolism This is an SGEMHOP episode and we have the lead author of this quantitative study, Dr. Lauren Westafer. Lauren is an emergency medicine physician practicing in Massachusetts, and avid FOAM producer. Authors’ Conclusions: “Our findings suggest that common barriers exist to the use of risk stratification tools in the evaluation of pulmonary embolism in the ED and provide insight into where to focus efforts for future implementation endeavors. Overall, provider-level factors such as risk avoidance and lack of knowledge of the tools dominated as barriers, while inner-setting factors were identified as facilitators. Future efforts to improve evidence based diagnosis of pulmonary embolism should focus on implementation strategies targeting these domains.” CASP Checklist for Qualitative Research Was there a clear statement of the aims of the research? Yes Is a qualitative methodology appropriate? Yes Was the research design appropriate to address the aims of the research? Yes Was the recruitment strategy appropriate to the aims of the research? No. Emails were sent to a purposive sample of physicians, many of whom were colleagues of the principal investigators and thus there would be bias as to those physicians potentially known practice patterns and potential responses. We do know that two physicians declined, and an effort was made to have a cross-section experience (years in practice), gender and practice setting (academic vs. community based). Was the data collected in a way that addressed the research issue? Yes Has the relationship between researcher and participants been adequately considered? Unsure. As before, the researcher was a colleague with six of the 23 study participants, this will introduce some bias. Have ethical issues been taken into consideration? Yes Was the data analysis sufficiently rigorous? Yes Is there a clear statement of findings? Yes How valuable is the research? The external validity of this study is seriously questionable given the small number of participants and practice setting of four Northeastern US emergency settings. There may be generalizability to the American practice setting, but I question its applicability in Canada, Europe, the ANZACS and other areas of the world. That said, there is value in recognizing what barriers and facilitators practicing physicians find for the use of any clinical decision making or decision instrument. The same themes often emerge regardless of where you are in the world. For example, fear, anxiety, uncertainty, knowledge gaps and medicolegal risk are all barriers that need to be addressed when working up patients for any disease process. The study also identifies that physicians are more comfortable making decisions that are clearly aligned with institutional goals/policies as well as in line with their colleagues practice patterns. Audit and feedback were also identified as a helpful tool by some physicians. Audit and feedback can be an extremely powerful tool if delivered well, I will encourage those who are interested to read the following paper. “Audit and Feedback for individual practitioners in the Emergency Department: An Evidence-based and Practical Approach” was recently published in CJEM and covers critical elements of implementing an ED based audit and feedback program (Dowling et al CJEM 2020). Key Results: They had 23 physicians from a total of 12 academic and community hospitals in New England were interviewed. Two potential participants declined. Participants had a median of 14 years in practice, 48% practiced solely in an academic setting, 20% practiced exclusively in a community ED and the remaining 32% practiced in a combination of academic and community EDs. All clinicians reported some familiarity and some use of risk-stratification tools, particularly PERC in the workup of PE. Barriers: Clinician-level barriers to use of risk-stratification tools centered on knowledge, belief about consequences and emotions. There was a lack of knowledge regarding validated cutoffs for the Wells score, lack of knowledge of a trichotomized Wells threshold, and most providers would only use a D-dimer for patients with a Wells score less than or equal to 3. Providers reported more confidence in their gestalt than risk stratification tools. They commonly reported that if a patient satisfied “PE is the most likely diagnosis” or there was a prior history of venous thromboembolism (VTE) or had active malignancy, the patient would automatically be too high risk to order a D-Dimer. Beliefs about consequences of using the tools, particularly risk avoidance and fear of missing PE were also common provider-level barriers. Nearly all participants were unaware of existing professional guidelines on PE. Facilitators: Study participants reported facilitators primarily at the level of the institutional setting. All clinicians felt that institutional support and a clear easy-to-follow algorithm endorsed by their hospital or group would facilitate their use of evidence-based approaches. This would also need to be easily accessible on shift. They also felt this would provide perceived medicolegal protection and establish a cultural norm of practice, and cited peer pressure as a root cause to motivate them to change practice. Clinicians felt that simplicity of PERC facilitated its use, while the element of gestalt incorporated into Wells made it more challenging to use.