Variation in CTA evaluation of ED patients suspected of aortic dissection.

PURPOSE: This study was performed to investigate the variation in CTA imaging for AoD in an ED to determine if limiting the scanned region to the chest can effectively rule-out AoD without delaying care. METHODS: A retrospective chart review was performed for all patients belonging to a geographically isolated health maintenance organization who underwent CTA evaluation for possible acute AoD in the emergency department between 2016 and 2020. We evaluated for the regions included in the CTA, the presence of an acute AoD, and clinical outcomes. For those who were ruled-out of an AoD with a CTA limited to the chest, we investigated clinical follow-up up to 6 months after their initial presentation. RESULTS: Over the study period, there were 1143 CT scans ordered by ED physicians to evaluate for AoD in patients without a history of AoD. Only 23.0% of screening studies were of the chest only. There were 29 acute AoDs diagnosed (14 type A and 15 type B) making for a prevalence of 2.5%. Only one patient with an acute AoD detected on a chest-only CTA required farther imaging, which did not delay clinical care. No patients ruled-out for acute AoD with a chest-only CTA had a return ED visit or repeat CTA within 6 months diagnosing a missed AoD. There were no AoDs limited to the abdominal aorta that would have been missed on a chest-only study. CONCLUSION: In patients in the ED with suspected new acute AoD, a CTA limited to the chest can effectively evaluate the condition without delaying care in this integrated healthcare system with 24/7 CT availability.

Recommended D-Dimer Use in Suspected Pulmonary Embolism Is Insufficient to Curb the Long-Term Overutilization of CT Pulmonary Angiography.

PURPOSE: The aim of this study was to determine whether the authors' emergency medicine department has seen a significant change in CT pulmonary angiography (CTPA) utilization or positive rates for pulmonary embolism (PE) over a 10-year period for the 2 years before and 8 years after the implementation of patient population-specific D-dimer recommendations. METHODS: A retrospective chart review was performed among all patients belonging to a geographically isolated health maintenance organization who underwent CTPA for the evaluation of acute PE in the emergency department between 2010 and 2019. The positive rate for acute PE among these studies was calculated and stratified by serum D-dimer value collected within 48 hours previously. RESULTS: A total of 6,013 CT pulmonary angiographic studies were reviewed, of which 40.2% had serum D-dimer ≥ 1.0 µg/mL (positive rate 10.6%), 42.5% did not have serum D-dimer drawn (positive rate 7.3%), and 17.2% had serum D-dimer < 1.0 µg/mL (positive rate 0.6%). There was a significant increase in positivity on CTPA in 2012 with the health group's formal recommendation of a D-dimer cutoff of 1.0 µg/mL. This improvement also corresponded with fewer orders for CTPA after a negative D-dimer result. However, in the following years, CTPA utilization and percentage positivity were found to be reverting to the prerecommendation statistics. CONCLUSIONS: The failure to mandate the use of serum D-dimer with a higher threshold value for patients who are to undergo CTPA for possible PE has resulted in poor lasting compliance despite promising early results. A firmer approach is likely necessary to yield positive long-term outcomes.