Emergency Medicine Case Series: Episode 1

Panel:
Pramod Chandru and Shreyas Iyer.

Case Summary:

• 61-year-old male presenting with 2 distinct episodes of shortness of breath, chest pain, and associated presyncope.  
• Asymptomatic by the time of arrival to the emergency department.  
• ECG and observations at triage were unremarkable. 
• No recent travel or recent major surgeries. 
• Initial troponin and serial troponin were 80ng/L.  
• D-dimer was ordered given static troponin and the nature of symptoms: 0.58. 
• Although this D-dimer was negative when age-adjusted, a V/Q scan was pursued as the patient was not felt to fit a ‘low risk’ pre-test probability for PE (IV contrast shortage dictated V/Q over CTPA). 
• Bilateral segmental pulmonary PE identified on V/Q scan with mild right heart strain evident on subsequent CTPA and TTE.  

Key Discussion Points:

• If a case does not follow the usual ‘pattern’ of your initial diagnosis, consider alternate aetiologies. 
• There are many tools available for risk-stratifying PE including PERC, age-adjusted D-dimer, and the YEARS diagnostic pathway. However, the way in which to appropriately utilize these tools is nuanced.  
• A paper published in JAMA in December 2021 demonstrates some ways in which these tools can be used together (see first reference below).  
• The PESI score (even prior to definitive diagnosis) can be useful to risk stratify patients with possible PE and help determine their disposition.  

Take-Home Points:

• Pre-test probability is incredibly important, particularly in entities such as PE where only highly invasive imaging modalities are diagnostic. 
• Having a structured approach to protect yourself from your own mistakes is extremely important (such as a hypothesis and hypothesis testing approach). 

References & Background Reading: 

• Effect of a Diagnostic Strategy Using an Elevated and Age-Adjusted D-Dimer Threshold on Thromboembolic Events in Emergency Department Patients With Suspected Pulmonary Embolism: A Randomized Clinical Trial. JAMA. 2021 Dec 7;326(21):2141-2149. doi: 10.1001/jama.2021.20750. 
• Thiruganasambandamoorthy, V., Stiell, I.G., Sivilotti, M.L. et al. Risk stratification of adult emergency department syncope patients to predict short-term serious outcomes after discharge (RiSEDS) study. BMC Emerg Med 14, 8 (2014). https://doi.org/10.1186/1471-227X-14-8.
• Crane SD, Risk stratification of patients with syncope in an accident and emergency department Emergency Medicine Journal 2002;19:23-27.
• Almulhim KN. The Characteristics of Syncope-Related Emergency Department Visits: Resource Utilization and Admission Rate Patterns in Emergency Departments. Cureus. 2022 Feb 8;14(2):e22039. doi: 10.7759/cureus.22039. PMID: 35340474; PMCID: PMC8913182. 
• Iwuji K, Almekdash H, Nugent KM, Islam E, Hyde B, Kopel J, Opiegbe A, Appiah D. Age-Adjusted D-Dimer in the Prediction of Pulmonary Embolism: Systematic Review and Meta-analysis. J Prim Care Community Health. 2021 Jan-Dec;12:21501327211054996. doi: 10.1177/21501327211054996. PMID: 34814782; PMCID: PMC8640977. 
• Schouten HJ, Geersing GJ, Koek HL, et al. Diagnostic accuracy of conventional or age-adjusted D-dimer cut-off values in older patients with suspected venous thromboembolism: systematic review and meta-analysis. 2012. In: Database of Abstracts of Reviews of Effects (DARE): Quality-assessed Reviews [Internet]. York (UK): Centre for Reviews and Dissemination (UK); 1995-. Available from: https://www.ncb