פוסט זה זמין גם ב: עברית
Abstract
Point-of-care ultrasound (POCUS) is becoming ubiquitous in emergency medicine. POCUS for abdominal aortic aneurysm is well established in practice. The thoracic aorta can also be assessed by POCUS for dissection and aneurysm and transthoracic echocardiography is endorsed by international guidelines as an initial test for thoracic aortic pathologies. A systematic search of Ovid Medline, PubMed, EMBASE, SCOPUS and Web of Science from January 2000 to August 2022 identified four studies evaluating diagnostic accuracy of emergency physician POCUS for thoracic aortic dissection (TAD) and five studies for thoracic aortic aneurysm (TAA). Study designs were heterogeneous including differing diagnostic criteria for aortic pathology. Convenience recruitment was frequent in prospective studies. Sensitivity and specificity ranges for studies of TAD were 41–91% and 94–100%, respectively when an intimal flap was seen. Sensitivity and specificity ranges for studies of thoracic aorta dilation >40 mm were 50–100% and 93–100%, respectively; for >45 mm ranges were 64–65% and 95–99%. Literature review identified that POCUS is specific for TAD and TAA. POCUS reduces the time to diagnosis of thoracic aortic pathology; however, it remains insensitive and cannot be recommended as a stand-alone rule-out test. We suggest that detection of thoracic aorta dilation >40 mm by POCUS at any site increases the suspicion of serious aortic pathology. Studies incorporating algorithmic use of POCUS, Aortic Dissection Detection Risk Score and D-dimer as decision tools are promising and may improve current ED practices. Further research is warranted in this rapidly evolving field.
Key findings
- POCUS is specific for thoracic aortic aneurysm as well as for thoracic aortic dissection when an intimal flap is seen directly and can reduce the time to diagnosis.
- Indirect signs of thoracic aortic dissection are less specific. In the correct clinical context visualisation of any indirect signs should trigger up-triage of pending advanced imaging requests.
- POCUS cannot be used in isolation to rule-out acute aortic syndromes in the ED. It is possible that combining POCUS with D-dimer and/or ADD-RS will be established as a safe approach in future studies.